Glossary for Nystagmus

• $18p minus syndrome$: A rare chromosomal disorder where a portion of chromosome 18 is missing which is characterized by mental and growth deficiencies, drooping upper eyelid and prominent ears. The type and severity of symptoms is determined by the amount of genetic material that is missing.
• Abetalipoproteinemia: A rare disorder involving abnormalities in fat metabolism. The resulting insufficiency of fats and vitamins affect the normal development and function of the body.
• Ablinism I syndrome: A recessively inherited form of albinism involving the complete lack of skin, hair and eye pigments.
• Absence of septum pellucidum and septo-optic dysplasia: A rare birth defect where a thin membrane in the middle of the brain is missing. This brain abnormality is never present on it's own but is a characteristic of septo-optic dysplasia where the patient also has optic disk abnormalities and pituitary deficiencies.
• Absence of septum pellucidum with porencephalia syndrome: A rare syndrome present at birth and characterized by the absence of the thin membrane in the middle of the brain (septum pellucidum) as well as abnormal cavities in the brain (porencephaly). The syndrome also involves other structural brain abnormalities.
• Acanthocytosis: A rare disorder where most of the red blood cells are abnormal with spiny projections due to lipid abnormalities. The blood abnormality is seen in conditions such as abetalipoproteinemia, severe liver disease and severe malnutrition. Symptoms and prognosis depend on the underlying disorder.
• Achromatopsia: A rare condition characterized by color blindness - there are various subtypes.
• Achromatopsia incomplete, X-linked: An inherited form of blue color blindness.
• Acoustic neuroma: A benign tumor of the 8th cranial nerve which lies in the tube connecting the inner ear to the brain.
• Adams Nance syndrome: A rare genetic disorder characterized by rapid heartbeat, high blood pressure, small eyes and the presence of excess glycine in the urine.
• Adrenoleukodystrophy, autosomal, neonatal form: A rare inherited disorder involving the adrenal glands, testes and certain parts of the brain (white matter). It is a less severe form of leukodystrophy where an abnormality within the body cells prevents the metabolism of certain fats (long chain fatty acids).
• Adversive syndrome: A rare condition where the patient turns compulsively when trying to move forwards. It can be caused by damage to a part of the brain called the Brodmann's area, neurosurghery, brain tumor or other brain lesions.
• Albinism: A rare inherited condition characterized by a lack of pigmentation in the hair, skin and/or eyes.
• Alcohol abuse: Excessive use of alcohol ranging from binge drinking to severe alcoholism
• Alcoholism: Excessive addictive use of alcohol.
• Alstrom syndrome: A rare genetic disorder involving a group of abnormalities affecting vision, hearing, kidney function and also characterized by obesity and diabetes mellitus.
• Amaurosis congenita of Leber, type 1: A rare inherited retinal disease (retinal dystrophy) that starts during the fetal stage. Vision impairment is obvious at birth or within months of birth. Type I is distinguished from the other forms of this condition by the genetic origin of the defect - chromosome 17p13.1, RETGC1 gene.
• Amaurosis congenita of Leber, type 10: A rare inherited retinal disease (retinal dystrophy) that starts during the fetal stage. Vision impairment is obvious at birth or within months of birth. Type 10 is distinguished from the other forms of this condition by the genetic origin of the defect - chromosome 12, CEP290 gene.
• Amaurosis congenita of Leber, type 11: A rare inherited retinal disease (retinal dystrophy) that starts during the fetal stage. Vision impairment is obvious at birth or within months of birth. Type 11 is distinguished from the other forms of this condition by the genetic origin of the defect - chromosome 7q, IMPDH1 gene.
• Amaurosis congenita of Leber, type 2: A rare inherited retinal disease (retinal dystrophy) that starts during the fetal stage. Vision impairment is obvious at birth or within months of birth. Type 2 is distinguished from the other forms of this condition by the genetic origin of the defect - chromosome 1, RPE65 gene.
• Amaurosis congenita of Leber, type 3: A rare inherited retinal disease (retinal dystrophy) that starts during the fetal stage. Vision impairment is obvious at birth or within months of birth. Type 3 is distinguished from the other forms of this condition by the genetic origin of the defect - chromosome 14q23.3, RDH12 gene.
• Amaurosis congenita of Leber, type 4: A rare inherited retinal disease (retinal dystrophy) that starts during the fetal stage. Vision impairment is obvious at birth or within months of birth. Type 4 is distinguished from the other forms of this condition by the genetic origin of the defect - chromosome 17p13.1, AIPL1 gene.
• Amaurosis congenita of Leber, type 5: A rare inherited retinal disease (retinal dystrophy) that starts during the fetal stage. Vision impairment is obvious at birth or within months of birth. Type 5 is distinguished from the other forms of this condition by the genetic origin of the defect - chromosome 6q11-q16.
• Amaurosis congenita of Leber, type 6: A rare inherited retinal disease (retinal dystrophy) that starts during the fetal stage. Vision impairment is obvious at birth or within months of birth. Type 6 is distinguished from the other forms of this condition by the genetic origin of the defect - RPGRIP1 gene.
• Amaurosis congenita of Leber, type 7: A rare inherited retinal disease (retinal dystrophy) that starts during the fetal stage. Vision impairment is obvious at birth or within months of birth. Type 7 is distinguished from the other forms of this condition by the genetic origin of the defect - CRX gene.
• Amaurosis congenita of Leber, type 8: A rare inherited retinal disease (retinal dystrophy) that starts during the fetal stage. Vision impairment is obvious at birth or within months of birth. Type 8 is distinguished from the other forms of this condition by the genetic origin of the defect - CRB1 gene.
• Amaurosis congenita of Leber, type 9: A rare inherited retinal disease (retinal dystrophy) that starts during the fetal stage. Vision impairment is obvious at birth or within months of birth. Type 9 is distinguished from the other forms of this condition by the genetic origin of the defect - chromosome 1p36.
• Amaurosis hypertrichosis: A rare syndrome characterized by severe retinal dystrophy and excessive growth of hair.
• Ampola syndrome: A rare genetic disease characterized primarily by mental retardation, facial anomalies, short stature, seizures and finger and toe abnormalities.
• Amyloidosis, oculoleptomeningeal: Amyloidosis involves the abnormal deposit of a substance called amyloid in various parts of the body. In this particular type, the amyloid deposits in the leptomeningeal blood vessels, brainstem, spinal cord and eye causing central nervous system dysfunction, brain hemorrhages and vision impairment.
• Aniridia: A genetic disorder where part or all of the iris of one or both eyes is missing. The iris is the colored part of the eye. There are four forms of the disease: AN-1, AN-II, AN-III and AN-IV.
• Aniridia - ptosis - mental retardation - obesity, familial: A rare familial disorder characterized by eye abnormalities, mental retardation and obesity.
• Aniridia, sporadic: A rare eye malformation where part or all of the iris of the eye is missing at birth.
• Arima syndrome: A rare disorder characterized mainly by eye and brain abnormalities.
• Arnold Stickler Bourne syndrome: A very rare syndrome characterized by muscle problems in hands, mouth and pharynx, kidney anomalies and corneal crystals.
• Arnold-Chiari malformation type 3: An extremely rare malformation where the base of the brain enters into the upper spinal canal. Type 3 involves the herniation of brain or brain stem tissue out of the back of the neck or head. The condition generally has a poor prognosis.
• Arnold-Chiari malformation type 4: Arnold-Chiari malformation is a rare malformation where the base of the brain enters into the upper spinal canal. Type 4 actually involves a lack of development of a portion of the base of the brain (cerebellum). The prognosis is very poor with death often occurring during infancy.
• Arthritis - short stature - deafness: A very rare syndrome characterized by arthritis, short stature, deafness and numerous other abnormalities.
• Ataxia spastic congenital miosis: A rare, dominantly inherited disorder characterized mainly by ataxia, spasticity and small pupils that respond poorly to light.
• Ataxia tapetoretinal degeneration: Conditions involving incoordination and an eye anomaly.
• Ataxia, Hereditary, Autosomal Dominant: A group of rare, dominantly inherited neuromuscular disorder involving degeneration of the brain and spinal cord. The range, progression and severity of symptoms can vary quite considerably depending on the genetic defect involved.
• Ataxia, spastic with congenital miosis: A rare disorder characterized by movement problems of the limbs as well as an impaired pupil reaction to light (miosis).
• Auricular abnormalities - cleft lip with or without cleft palate - ocular abnormalities: A rare syndrome characterized by the association of external ear and eye abnormalities, cleft lip and sometimes a cleft palate.
• Auriculoocular anomalies - cleft lip: A very rare syndrome characterized by the association of abnormal external ears and a cleft lip and sometimes a cleft palate. Only two cases of the condition has been reported.
• Babinski-Nageotte syndrome: A rare disorder caused by damage to a part of the brain (medullobulbar transitional area) which causes a variety of neurological symptoms, some of which affect only one side of the body.
• Bardet-Biedl Syndrome: A rare genetic disorder characterized by mental retardation, obesity, polydactyly and retinal pigmentation as well as other abnormalities.
• Bardet-Biedl syndrome, type 1: A rare genetic disorder characterized by mental retardation, obesity, polydactyly and retinal pigmentation as well as other abnormalities. Type 1 is caused by a defect in chromosome 11q13.
• Bardet-Biedl syndrome, type 10: A rare genetic disorder characterized by mental retardation, obesity, polydactyly and retinal pigmentation as well as other abnormalities. Type 10 is caused by a defect in chromosome 12q.
• Bardet-Biedl syndrome, type 11: A rare genetic disorder characterized by mental retardation, obesity, polydactyly and retinal pigmentation as well as other abnormalities. Type 11 is caused by a defect in chromosome 9q33.1.
• Bardet-Biedl syndrome, type 12: A rare genetic disorder characterized by mental retardation, obesity, polydactyly and retinal pigmentation as well as other abnormalities. Type 12 is caused by a defect in chromosome 4q27.
• Bardet-Biedl syndrome, type 2: A rare genetic disorder characterized by mental retardation, obesity, polydactyly and retinal pigmentation as well as other abnormalities. Type 2 is caused by a defect in chromosome 16q21.
• Bardet-Biedl syndrome, type 3: A rare genetic disorder characterized by mental retardation, obesity, polydactyly and retinal pigmentation as well as other abnormalities. Type 3 is caused by a defect in chromosome 3p12-q13.
• Bardet-Biedl syndrome, type 4: A rare genetic disorder characterized by mental retardation, obesity, polydactyly and retinal pigmentation as well as other abnormalities. Type 4 is caused by a defect in chromosome 15q22.3.
• Bardet-Biedl syndrome, type 5: A rare genetic disorder characterized by mental retardation, obesity, polydactyly and retinal pigmentation as well as other abnormalities. Type 5 is caused by a defect in chromosome 2q31.
• Bardet-Biedl syndrome, type 6: A rare genetic disorder characterized by mental retardation, obesity, polydactyly and retinal pigmentation as well as other abnormalities. Type 6 is caused by a defect in chromosome 20p12.
• Bardet-Biedl syndrome, type 7: A rare genetic disorder characterized by mental retardation, obesity, polydactyly and retinal pigmentation as well as other abnormalities. Type 7 is caused by a defect in chromosome 4q27.
• Bardet-Biedl syndrome, type 8: A rare genetic disorder characterized by mental retardation, obesity, polydactyly and retinal pigmentation as well as other abnormalities. Type 8 is caused by a defect in chromosome 14q32.11.
• Bardet-Biedl syndrome, type 9: A rare genetic disorder characterized by mental retardation, obesity, polydactyly and retinal pigmentation as well as other abnormalities. Type 9 is caused by a defect in chromosome 7p14.
• Benign Paroxysmal Positional Vertigo: A condition where certain head movements cause extreme dizziness.
• Blue cone monochromatism: A genetic eye disorder where the S cones function normally but the L and M cones don't resulting in poor color vision.
• Bone marrow failure - neurologic abnormalities: A rare syndrome characterized by the association of bone marrow failure and neurological abnormalities.
• Bonnier's syndrome: A range of symptoms caused by damage to Dieter's nucleus (the lateral nucleus of the vestibular nerve) or its connections.
• Borjeson Syndrome: A rare genetic disorder characterized by severe mental deficiency, large ears, hypogonadism and other abnormalities.
• Brachmann-De Lange Syndrome: A rare congenital disorder characterized by very small stature, synophrys, thin downturning upper lip and micromelia.
• Brain cancer: Cancer of the brain.
• Branchio-skeleto-genital syndrome: A rare inherited disorder characterized by mental retardation, jaw anomalies, cleft palate, sunken chest and other abnormalities.
• Brown-Symmers disease: A rare form of brain inflammation that occurs in children and can quickly lead to death. Symptoms usually start suddenly.
• $CRAPB$: A rare inherited eye disorder involving slow-progressing chorioretinal damage which leads to vision impairment.
• Cardiofaciocutaneous Syndrome: A rare genetic disorder characterized by short stature, congenital heart defects skin anomalies and frontal bossing.
• Cataract and cardiomyopathy: A rare syndrome characterized by the association of congenital cataracts, heart muscle disease, lactic acidosis and skeletal muscle disease. The disorder involves the abnormal storage of lipids and glycogen in the skeletal and heart muscles. The cataracts progress rapidly and require surgery. The severity of the disorder ranges from stillbirth to survival into the fourth decade.
• Cataract, microphthalmia and nystagmus: A rare genetic eye disorder characterized by congenital cataracts (cloudy eye lens), small eyes and rapid, involuntary eye movements.
• Caudal appendage - deafness: A very rare syndrome characterized mainly by deafness, finger bone abnormalities and a spinal extension giving a tail-like appearance (caudal appendage).
• Cerebellar abscess: An abscess that forms in the part of the brain called the cerebellum. The abscess may result from other infections such as ear infections, dental abscess and lung infections. The prognosis is determined by the size and exact location of the abscess
• Cerebellar ataxia, X-linked: A disorder where degeneration of certain parts of the brain results in symptoms such as ataxia. The rate of progression can vary.
• Cerebellar ataxia, areflexia, pes cavus, optic atrophy and sensorinural hearing loss: A rare syndrome characterized mainly by ataxia, absent reflexes, high foot arch (pes cavus), progressive optic nerve degeneration and hearing impairment. The ataxic symptoms tended to occur early in life after an illness involving fevers. The ataxia then tends to come and go but then persists into adulthood.
• Cerebellar degeneration: Degeneration of nerves in the part of the brain called the cerebellum which controls balance and muscle coordination.
• Cerebellar hypoplasia - endosteal sclerosis: A rare disorder character where a part of the brain (cerebellum) is underdeveloped and abnormally increased bone density (endosteal sclerosis).
• Cerebellar hypoplasia - tapetoretinal degeneration: A rare disorder character where a part of the brain (cerebellum) is underdeveloped and a nonprogressive eye disorder involving the retinal pigments. The cerebellum is the part of the brain that controls balance and movement.
• Cerebelloparenchymal autosomal recessive disorder 3: A rare, recessively inherited disorder characterized mainly by albinism, incoordination, low muscle tone and eye problems.
• Cerebral abscess: An abscess that forms in the part of the brain called the cerebrum. The abscess may result from other infections such as ear infections, dental abscess and lung infections. The prognosis is determined by the size and exact location of the abscess.
• Cerebro oculo skeleto renal syndrome: A very rare syndrome characterized mainly by brain, eye, skeletal and kidney abnormalities.
• Cerebrorenodigital syndrome: A rare group of syndromes characterized mainly by brain, kidney, finger and toe abnormalities.
• Cerebrovascular accident: Occurs when the blood supply to the brain is interrupted and results in cell injury and death.
• Cholesteatoma: Uncommon middle ear condition
• Chorioretinal atrophy, progressive bifocal: A slow-progressing, inherited, degenerative eye disease.
• Chromosome 10, trisomy 10pter p13: A rare chromosomal disorder where duplication of a portion of chromosome 10 causes various abnormalities such as a wasted build, gut and heart placement abnormalities and lack of reflexes.
• Chromosome 10p duplication syndrome: A rare chromosomal disorder where there are three copies of the short arm (p) of chromosome 11 rather than the normal two resulting in various abnormalities. The type and severity of symptoms depend on the amount and location of genetic material duplicated.
• Chromosome 11q duplication syndrome: A rare chromosomal disorder where there are three copies of the long arm (q) of chromosome 11 rather than the normal two resulting in various abnormalities. The type and severity of symptoms depend on the amount and location of genetic material duplicated.
• Chromosome 15q triplication syndrome: A rare chromosomal disorder where there are three copies of a part of the long arm of chromosome 15 resulting in various anomalies.
• Chromosome 18 deletion syndrome: A rare chromosomal disorder where a portion of chromosome 18 is missing.
• Chromosome 18q, partial deletion: A rare chromosomal disorder involving deletion of genetic material from the long arm of chromosome 18. The type and severity of symptoms are determined by the amount and location of the lost genetic material.
• Chromosome 6 ring syndrome: A rare chromosomal disorder where the ends of chromosome 6 have been deleted and the two broken ends have rejoined to form a ring shape resulting in a range of symptoms determined by the size of the genetic deletion.
• Chromosome 6, monosomy 6p23: A very rare chromosomal disorder characterized by various abnormalities including mental retardation, facial, finger and toe anomalies as well as heart, skeletal and neurological problems.
• Chromosome 8 recombinant syndrome: A rare recombinant chromosomal disorder involving chromosome 8 which results in various abnormalities.
• Chromosome 8p deletion syndrome: A rare chromosomal disorder involving deletion of the short arm (p) of chromosome 8 resulting in various abnormalities.
• Cockayne syndrome: A rare genetic disorder characterized by a senile-like appearance, hearing and vision impairment and sun sensitive skin.
• Coloboma chorioretinal cerebellar vermis aplasia: A very rare syndrome characterized by an eye anomaly (gap in eye structures such as choroids and retina) and abnormal development of the midline structure of the brain (cerebellar vermis aplasia).
• Combarros Calleja Leno syndrome: A rare disorder characterized by the association of glaucoma at birth with a form of ataxia.
• Congenital disorder of glycosylation type 1/IIX: Congenital disorders of glycosylation is a group of very rare inherited metabolic disorder where defective carbohydrate compounds are attached to glycoproteins and thus impairing glycoprotein function. Type I/IIX refers to cases where the specific abnormality cannot be determined.
• Corneal dystrophy - ichthyosis - microcephaly - mental retardation: A very rare syndrome characterized by vision loss, scaly skin, small head and mental retardation.
• Craniofacial dysostosis type 1: A rare genetic disorder characterized by premature joining of certain skull bones during development which has an impact on the shape of the head and face. Features include poor vision, hypoplasia of maxilla an impaired hearing.
• Céstan-Chenais syndrome: A rare brain stem disorder characterized by neurological abnormalities that occur on one side of the face but on the opposite side of the rest of the body. It is usually caused by damage to a part of the brain (pontobulbar area) or a blood clot in a particular part of the vertebral artery.
• Dandy-Walker - facial hemangioma: A very rare syndrome characterized mainly by a brain malformation (Dandy-Walker) and a hemangioma on the face (mass of dilated blood vessels).
• Dandy-Walker Syndrome: A congenital brain malformation characterized by increased fluid in the brain.
• Dandy-Walker malformation with mental retardation, macrocephaly, myopia, and brachytelephalangy: A very rare syndrome characterized mainly by mental retardation, large head, short fingers, nearsightedness and brain abnormalities (Dandy-Walker type).
• Decompression sickness: Condition from overly rapid decompression, especially when diving.
• Dobrow syndrome: A very rare syndrome characterized mainly by abnormal webbing inside the mouth, short stature, eye problems, mental retardation and small head, jaw, eyes and mouth.
• Donepezil toxicity: The toxic reaction of the body to the substance, possibly via allergic reaction or overdose.
• Down Syndrome: A chromosome syndrome causing physical effects and mental retardation.
• Drug abuse: Addiction to any of various illicit drugs.
• Encephalitis, California serogroup viral: A mosquito borne viral illness
• Episodic ataxia, type 2: A rare genetic disorder characterized by episodes of incoordination and unsteadiness as well as nystagmus (rapid, involuntary eye movements). Stress, exertion, alcohol and coffee may trigger the episodes which can last from hours to days. Type 2 is caused by a defect in the calcium ion gene on chromosome 19p13.
• Episodic ataxia, type 4: A rare genetic disorder characterized by episodes of incoordination and unsteadiness. Stress and exertion may trigger the episodes. Type 4 is distinguished from the other types by it's late onset - 3rd to 6th decade.
• Episodic ataxia, type 5: A rare genetic disorder characterized by episodes of incoordination, unsteadiness and seizures. Stress and exertion may trigger the episodes. Type 5 is caused by a defect on chromosome 2q22-q23.
• Ermine phenotype: A very rare syndrome characterized by pigmentation abnormalities as well as deafness.
• Erythrokeratodermia with ataxia: A rare syndrome characterized by the association of a skin disorder with slowly progressive neurological symptoms.
• Eye movement symptoms: Symptoms affecting the movement of the eye
• Fabry's Disease: Genetic fat storage disorder
• Fanconi pancytopenia: A rare genetic disorder characterized by upper limb defects and kidney abnormalities.
• Fanconi-Turler syndrome: A rare syndrome characterized mainly by mental retardation, ataxia and uncoordinated eye movements due to degeneration of parts of the brain.
• Fitzsimmons-McLachlan-Gilbert syndrome: A very rare syndrome characterized mainly by mental retardation paraplegia and thickened coarse skin on palms and soles.
• Forsius-Eriksson syndrome: A rare inherited disorder characterized by reduced eye pigmentation and various eye problems. The disorder is inherited in a familial X-linked manner so only males manifest the symptoms whereas females may be asymptomatic or suffer mild symptoms.
• Francois dyscephalic syndrome: A rare genetic disorder characterized by very small stature, microphthalmia, small pinched nose and hypotrichosis.
• Friedreich's ataxia: Progressive muscle weakness from nerve damage.
• GM1 gangliosidosis: A rare biochemical disorder involving a deficiency of an enzyme (beta-galactosidase A) which results in the accumulation of harmful chemicals (GM1 gangliosides) in the central nervous system and other body tissues. Type 1 is a severe infantile form of the disorder and involves a greater degree of accumulation than type II or III.
• Gangliosidosis generalized GM1, type 1: A rare biochemical disorder involving a deficiency of an enzyme (beta-galactosidase A) which results in the accumulation of harmful chemicals (GM1 gangliosides) in the central nervous system and other body tissues. Type 1 is a severe infantile form of the disorder and involves a greater degree of accumulation than type II or III.
• Griscelli disease: A rare genetic disorder characterized mainly by albinism (lack of pigmentation). There are three different subtypes of the disorder (I, II and III) each with varying additional features such as immunodeficiency and neurological symptoms. Type 1 involves partial albinism and neurological symptoms, type II involves partial albinism, immunodeficiency and sometimes neurological symptoms and type III involves albinism, only.
• Griscelli syndrome type II: A rare genetic condition characterized by a partial lack of pigmentation in the eye, skin and hair, clumps of pigmentation in hair shafts, immunodeficiency and neurological symptoms.
• Hajdu-Cheney Syndrome: A rare genetic disorder characterized by early tooth loss, relaxed joints, small stature and bone abnormalities.
• Hemiplegic migraine, familial type 1: A rare inherited form of migraine that characteristically causes temporary paralysis on one side of the body and involves the presence of an aura. A migraine episode may be triggered by minimal trauma to the head. The severity of the disorder is variable with some patients experiencing paralysis on one side of the body or coma for weeks.
• Hepatic encephalopathy syndrome: A rare syndrome involving the association of advanced liver disease and neurological problems.
• Hersh-Podruch-Weisskopk syndrome: A very rare syndrome characterized mainly by progressive retinal damage, mental retardation and deafness.
• Homocystinuria due to defect in methylation (cbl g): An inherited organic acid disorder where an enzyme deficiency (methionine synthase) impairs the body's ability to break down certain proteins consumed in the diet. This results in a buildup of methylmalonic acid and homocystine which results in harmful affects. It is a form of vitamin B12 deficiency.
• Homocystinuria due to defect in methylation cbl e: An inherited organic acid disorder where an enzyme deficiency (methionine synthase reductase) impairs the body's ability to break down certain proteins consumed in the diet. This results in a buildup of methylmalonic acid and homocystine which results in harmful affects. It is a form of vitamin B12 deficiency.
• Hydroxyacyl-coa dehydrogenase, type 2, deficiency: A rare genetic disorder involving the deficiency of an enzyme (hydroxyacyl-coa dehydrogenase). The severity of the symptoms is highly variable with some cases resulting in death during the first decade while others suffer psychomotor and regression. Some cases simply involve developmental delay.
• Hypertrophic neuropathy of Dejerine-Sottas: An inherited neurological disease characterized by the gradual degeneration of nerves which starts in the hands and feet and results in numbness, muscle weakness and loss of function. The severity of the condition is variable.
• Hypomagnesemia primary: Low blood magnesium levels which is caused by the abnormal absorption and excretion of the mineral and can be caused by such things as kidney problems and intestinal malabsorption.
• Hypomyelination - hypogonadotropic hypogonadism - hypodontia: A rare syndrome characterized by delayed puberty, missing teeth and reduced myelination which causes progressive ataxia.
• Incontinentia Pigmenti: A rare genetic skin pigmentation disorder characterized by eye, teeth, bone, nail and hair malformations as well as central nervous abnormalities and mental deficiency.
• Infantile Refsum Disease: Genetic disease affecting nerve and muscle control.
• Infantile sialic acid storage disorder: A rare inherited biochemical disorder characterized by the accumulation of sialic acid in the tissues and excretion of sialic acid in the urine. The disorder results in death within the first few years of life - usually in infancy.
• Kallmann Syndrome: A rare inherited condition characterized by hypogonadism, eunuchoidism and impaired or absent sense of smell. The condition occurs as a result of failure of a part of the hypothalamus which results in hormonal imbalance.
• Karandikar-Maria-Kamble syndrome: A very rare syndrome characterized mainly by cataracts, mental retardation and genitourinary tract abnormalities and
• Kaufman oculocerebrofacial syndrome: A rare syndrome characterized by a small head, narrow face, eye anomalies, severe mental retardation and long thin hands and feet. The disorder is recessively inherited.
• Klippel Feil Syndrome: A rare congenital disorder characterized by abnormal fusion of two or more vertebrae in the neck. The disorder is often associated with other abnormalities but their incidence is highly variable.
• Krause-Kivlin syndrome: A rare genetic disorder characterized by short limb dwarfism, mental retardation and Peters anomaly.
• Labrynthitis: Inner ear condition affecting various ear structures
• Lissencephaly with cerebellar hypoplasia, recessive: Abnormal brain development where the brain is abnormally smooth and the cerebellum is underdeveloped.
• Lowry-Wood syndrome: A rare syndrome characterized by a small head, rapid involuntary eye movements (nystagmus) and abnormal development of the ends of long bones where growth occurs.
• Luteinizing hormone releasing hormone, deficiency of, with ataxia: A very rare syndrome characterized mainly by insufficient sex hormone production and impaired balance and coordination due to nervous system dysfunction.
• MOMO syndrome: A very rare syndrome characterized mainly by a large size and weight at birth, a large head and eye abnormalities.
• Macular dystrophy, retinal, 1, North Carolina type: A rare genetic eye disorder that affects the central part of the retina (macula).
• Manz syndrome: A rare inherited kidney disorder characterized low blood magnesium and high urine calcium levels as well as nystagmus.
• Marinesco-Sjogren syndrome: A group of recessively inherited disorder characterized mainly by incoordination due to a brain anomaly.
• Meier-Blumberg-Imahorn syndrome: A very rare syndrome characterized mainly by high urine calcium level and eye problems.
• Mental retardation - blepharophimosis - obesity - web neck: A very rare syndrome characterized mainly by mental retardation, eye abnormalities, obesity and a webbed neck.
• Mental retardation - macrocephaly - coarse facies - hypotonia: A very rare syndrome characterized mainly by mental retardation, large head, coarse face and reduced muscle tone.
• Mental retardation - skeletal dysplasia - abducens palsy: A very rare syndrome characterized mainly by mental retardation, skeletal abnormalities and weakness of an eye muscle.
• Mental retardation, Mietens-Weber type: A very rare genetic condition characterized by mental retardation, corneal opacity, nystagmus, elbow contractures and dwarfism.
• Methylcobalamin deficiency, cbl E complementation type: An inherited organic acid disorder where an enzyme deficiency (cbl E) impairs the body's ability to break down cobalamin in the diet. This results in a buildup of homocystine which results in harmful affects.
• Microcephaly - mental retardation - retinopathy: A very rare syndrome characterized mainly by a small head, mental retardation and retinal disease.
• Microcephaly - microphthalmos - blindness: A very rare syndrome characterized mainly by a small head, small eyes and blindness.
• Minamata disease: Ingestion of seafood containing methylmercury can result in neurological toxicity symptoms.
• Multiple Sclerosis: Autoimmune attack on spinal nerves causing diverse and varying neural problems.
• Ménière's disease: Ear fluid disorder causing balance problems.
• Neuroaxonal dystrophy - renal tubular acidosis: A very rare syndrome characterized mainly by muscle and kidney abnormalities.
• Neurofibromatosis-Noonan syndrome: A rare disorder where the patients has symptoms of neurofibromatosis (nerve tumors) and Noonan syndrome (short stature, bleeding problems, heart defect, unusual facial features, skeletal anomalies, webbed neck).
• Neuronal intranuclear inclusion disease: A very rare syndrome characterized mainly by muscle and nerve degeneration.
• Night blindness, congenital stationary, type 2A: A rare X-linked disorder of the retina that involves the rods of the eyes. A reduced sharpness of vision and night blindness are usually the only symptoms. The non-progressive disorder is linked to a defect at chromosome Xp11.23 and occurs only in males though females may be carriers.
• Night blindness, congenital stationary, type 2B: A rare inherited disorder of the retina that involves the rods of the eyes. A reduced sharpness of vision and night blindness are usually the only symptoms. The non-progressive disorder is recessively inherited and is linked to a defect at chromosome 11q13.1.
• Noonan Syndrome: A rare genetic disorder characterized by a webbed neck, chest deformity, undescended testes and pulmonic stenosis.
• OFD syndrome type 8: A rare genetic disorder characterized by oral frenula, oral clefts, underdeveloped nose flapss and finger abnormalities.
• OFD syndrome type IX: A rare genetic disorder characterized by oral frenula, oral clefts, underdeveloped nose flapss and finger and retinal abnormalities.
• Ocular Albinism type 1: A rare eye disorder characterized primarily by lack of eye pigmentation. Females tend to have few if any symptoms as the condition is X-linked.
• Ocular albinism: A rare inherited disorder where a person lacks pigments in the eye. Vision problems may be involved.
• Oculo-osteo-cutaneous syndrome: A rare syndrome characterized mainly by eye, skeletal and skin abnormalities.
• Oculocerebral hypopigmentation syndrome, type Preus: A very rare syndrome characterized mainly by eye, brain and pigmentation abnormalities.
• Oculocutaneous albinism, type 3: A rare inherited disorder characterized by slightly reduced pigmentation in the skin, eyes and hair (due to a genetic mutation of the TYRP1 gene). Type 3 is characterized by some pigmentation of the iris despite the complete absence of tyrosinase which is needed for the production of melanin which gives the skin, hair and eyes their color. Type 3 also has the milder eye problems than the other types.
• Oculocutaneous albinism, type 4: A rare inherited disorder characterized by reduced pigmentation in the skin, eyes and hair. Type 4 involves a normal levels of tyrosinase which is needed for the production of melanin which gives the skin, hair and eyes their color. However, albinism is caused by mutation of the MATP gene (membrane associated transporter protein).
• Oculopalatoskeletal syndrome: A very rare syndrome characterized mainly by eye, mouth palate and skeletal abnormalities.
• Olivopontocerebellar atrophy - deafness: A very rare syndrome characterized mainly by brain abnormalities and deafness.
• Ophthalmoplegia, progressive external - scoliosis: A very rare syndrome characterized mainly by progressive eye muscle weakness and scoliosis.
• Opthalmoplegia progressive external scoliosis: A rare disorder characterized by progressive weakening of external eye muscles and scoliosis.
• Optic atrophy, idiopathic, autosomal recessive: A rare form of optic nerve dysfunction which is recessively inherited and is usually severe and starts at birth or soon after. by
• Optic pathway glioma: A type of tumor that arises in the optic nerve which sends messages from the eye to the brain. These tumors tend to occur mainly in children under the age of 10. The tumor may affect the hormone center of the brain and hence can affect such things as growth and weight.
• Osteosclerosis, abnormalities of nervous system and meninges: A very rare syndrome characterized mainly by increased bone density and nervous system abnormalities.
• Paraneoplastic cerebellar degeneration: Disorders of the cerebellum associated with tumors. The cerebellum is the part of the brain that controls coordination. It is believed that the body's immune system's attempt to destroy the tumor results in damage to the cerebellum. The main tumors associated with this condition include lung and breast cancer, Hodgkin's lymphoma and reproductive organ tumors.
• Pelizaeus-Merzbacher Disease: Rare brain myelin disorder.
• Pellagra-like syndrome: A rare disorder where the body is unable to metabolise tryptophan which causes a distinctive skin rash and neurological symptoms.
• Pena-Shokeir syndrome Type 2: A rare progressive congenital syndrome involving degeneration of the brain and spinal cord and characterized by facial, head, skeletal and muscular abnormalities as well as eye abnormalities.
• Phenytoin toxicity: The toxic reaction of the body to the substance, possibly via allergic reaction or overdose.
• Phillips-Griffiths syndrome: A rare syndrome characterized mainly by an eye defect called a coloboma and variable skeletal abnormalities.
• Pierson syndrome: A very rare syndrome characterized mainly by a small pupil and kidney disease at birth.
• Proud-Levine-Carpenter syndrome: A very rare syndrome characterized mainly by abnormal brain development, a small head and genital abnormalities.
• Pseudoadrenoleukodystrophy: A rare disorder where an enzyme deficiency (Acyl-CoA Oxidase) results in symptoms such as seizures, apnea, delayed psychomotor retardation and neurological deterioration.
• Ramsay Hunt syndrome: Facial paralysis with a vesicular eruption
• Red skin pigment anomaly of New Guinea: A rare skin anomaly observed in New Guinea natives where the skin is a reddish-brown color rather than the normal black.
• Refsum Disease: A metabolic disorder where a deficiency of phytanic acid alpha-hydroxylase results in a buildup of phytanic acid in the body which causes neurological disorders.
• Retinal degeneration - nanophthalmos - glaucoma: A very rare syndrome characterized by eye problems that has an early onset.
• Retinal dysplasia, X-linked: Abnormal development of the retina that affects males only and affects vision. The severity of the condition is variable and may involve retinal anomalies such as folds in the retina or blood vessel abnormalities within the eye.
• Retinis pigmentosa - deafness - hypogenitalism: A very rare syndrome characterized mainly by progressive retinal damage, deafness and genital anomalies.
• Retinitis pigmentosa - mental retardation - deafness: A very rare syndrome characterized mainly by progressive retinal damage, mental retardation and deafness.
• Richieri Costa Guion-Almeida syndrome: A very rare syndrome characterized mainly by mental retardation, short stature, cleft lip/palate and eye anomalies.
• Rufous oculocutaneous albinism: A rare inherited disorder characterized by abnormal pigmentation balance in the skin, eyes and hair (due to a genetic mutation of the MC1R gene). Tyrosinase, which is needed for the production of melanin which gives the skin, hair and eyes their color, is present but but a pigmentation imbalance causes a distinctive reddish coloration to the skin and hair.
• Sensory ataxic neuropathy, dysarthria, and ophthalmoparesis: A very rare syndrome characterized by progressive ataxia, eye muscle problems and a speech disorder (dysarthria).
• Septo-Optic Dysplasia: A rare birth defect characterized by impaired vision and pituitary deficiency.
• Sialidosis type 1 and 3: A rare inherited biochemical disorder involving the deficiency of an enzyme (alpha-N-acetylneuraminidase) which results in the harmful accumulation of certain chemicals (sialyloligosaccharides and sialylglycopeptides) in various body tissues.
• Sialuria, Finnish type: A rare inherited biochemical disorder characterized by the accumulation of sialic acid in the tissues and excretion of sialic acid in the urine. This condition is an adult form of sialuria.
• Singh-Chhaparwal-Dhanda syndrome: A very rare syndrome characterized mainly by short stature, mental retardation, eye defects and a missing kneecap.
• Spastic paraplegia 16, X-linked: A rare condition characterized by spasticity and weakness of the arms and legs, mental retardation, impaired vision and poor bowel and bladder control. In most cases, sufferers never gain the ability to walk.
• Spastic paraplegia 2, X-linked: A very rare genetic disorder characterized by lower leg spasticity and weakness. It has an early onset, progresses slowly and eventually the brain becomes involved as well which produces sensory, speech and eye problems.
• Spastic paraplegia 7, autosomal recessive: A rare syndrome characterized mainly by progressive stiffness and increased reflexes in the leg muscles.
• Sphingolipidosis: A group of diseases involving the abnormal metabolism and storage of a substance called sphingolipid. Symptoms will vary depending on the disease. Examples of diseases from this group include gangliosidosis, Gaucher's disease and Niemann-Pick disease.
• Spinocerebellar ataxia - dysmorphism: A rare inherited syndrome characterized by ataxia and unusual facial appearance.
• Spinocerebellar ataxia 10: A rare genetic disorder (chromosome 22q13 defect) characterized by gait ataxia and dysarthria (speech disorder). The severity of the condition is variable with some patients becoming wheelchair dependent.
• Spinocerebellar ataxia 11: A rare genetic disorder (chromosome 15q14-21.3 defect) characterized by gait ataxia and dysarthria (speech disorder). This form of the condition progresses slowly and doesn't affect life expectancy.
• Spinocerebellar ataxia 12: A rare genetic disorder (chromosome 5q31-q33 defect) characterized by variable symptoms such as arm tremors, gait ataxia and dysarthria (speech disorder) with other.
• Spinocerebellar ataxia 13: A rare genetic disorder (chromosome 19 defect) characterized by progressive mental retardation. Gait ataxia and dysarthria (speech disorder) also occur and are symptoms common to all the spinocerebellar ataxia types.
• Spinocerebellar ataxia 15: A rare genetic disorder (chromosome 3p26-p25 defect) characterized by gait ataxia, eye movement problems and dysarthria (speech disorder). The condition tends to progress slowly over decades with most patients retaining the ability to walk.
• Spinocerebellar ataxia 16: A rare genetic disorder (chromosome 3p26.2-pter defect) characterized by gait ataxia, eye movement problems, tremor and dysarthria (speech disorder). The progression of the condition is variable (1-40 years).
• Spinocerebellar ataxia 17: A rare genetic disorder (chromosome 6q27 defect) characterized by . Gait ataxia and dysarthria (speech disorder) also occur and are symptoms common to all the spinocerebellar ataxia types.
• Spinocerebellar ataxia 25: A rare genetic disorder (chromosome 2p15-p21 defect) characterized by sensory neuropathy and damage to the motor control part of the brain (cerebellar atrophy) resulting in ataxia. It is a slow progressing condition.
• Spinocerebellar ataxia 26: A rare genetic disorder (chromosome 19p13.3 defect) characterized by slowly progressive ataxia and dysarthria (speech disorder).
• Spinocerebellar ataxia 27: A rare genetic disorder (chromosome FGF14; 13q34 defect) characterized by tremors, dyskinesia and psychiatric episodes. Gait ataxia and dysarthria (speech disorder) also occur and are symptoms common to all the spinocerebellar ataxia types.
• Spinocerebellar ataxia 28: A rare genetic disorder (chromosome 18p11 defect) characterized by eye muscle paralysis (ophthalmoplegia) and increased reflexes. Gait ataxia and dysarthria (speech disorder) also occur and are symptoms common to all the spinocerebellar ataxia types.
• Spinocerebellar ataxia 29: A rare genetic disorder (chromosome 3p26 defect) characterized by nonprogressive ataxia that has an early onset.
• Spinocerebellar ataxia, X-linked, 5: A rare, X-linked neurological disorder which is not progressive and mainly involves ataxia, nystagmus and dysarthria.
• Spinocerebellar ataxia, autosomal dominant: A group of disorder involving slow progressing incoordination and speech and eye movement problems due to degeneration of the cerebellum of the brain. The various forms of the disorder vary according to the degree and range of muscle involvement.
• Stroke: Serious brain event from bleeding or blood clots.
• Syringobulbia: A neurological disorder that progresses slowly and is characterized by a fluid filled cavity in the spinal cord and brain stem.
• Tacrine toxicity: The toxic reaction of the body to the substance, possibly via allergic reaction or overdose.
• Unusual facies, hepatic fibrosis, renal cysts and mental retardation: A rare syndrome characterized mainly by liver fibrosis, unusual facial appearance, kidney cysts and mental retardation.
• Urban Schosser Spohn syndrome: A condition which is characterised by hereditary mucoepithelial dysplasia
• Verloes-Deprez syndrome: A rare syndrome characterized by the association of scoliosis, muscle disease and eye condition called Duane anomaly.
• Vestibular neuronitis: Infection of vestibular nerve.
• Volubilis, syndrome du: A rare birth defect of the optic papilla which is the part of the eye where the optic nerve emerges. Usually only one eye is affected.
• WAGR Syndrome: A syndrome that is due to the deletion of chromosome 11.
• Wallenberg's Syndrome: A rare neurological condition caused by a stroke (involving the cerebellar artery) and resulting in symptoms such as facial paralysis or weakness on one side of body.
• Wernicke-Korsakoff syndrome: A rare degenerative brain disorder caused by thiamine (Vitamin B1) deficiency. Chronic alcoholics are prone to this condition.
• Wilkie Taylor Scambler syndrome: A syndrome characterised by cataracts with microphthalmia and septal defect
• Yemenite deaf-blind hypopigmentation syndrome: A condition which is characterised by the association of several symptoms which affect ones hearing and vision
• Zonular cataract and nystagmus: Cataracts that affect only certain layers of the lens