Diseases » Klinefelter syndrome » Summary

What is Klinefelter syndrome?

What is Klinefelter syndrome?

• Klinefelter syndrome: A genetic condition where males have at least one extra X chromosome or extra copies of both the X and Y chromosomes in each cell. Normally male cells contain one X and one Y chromosome in each cell. The condition is not inherited but is a result of problems during cell division. Klinefelter syndrome variants is a more severe form of the condition as it involves more than one extra X or X and Y chromosome in each cell.
• Klinefelter syndrome: A common sex chromosomal anomaly in males characterized mainly by small testes with tubular hyalinization, azospermia with infertility, slight breast enlargement, elevated urinary gonadotropins, and decreased urinary 17-ketosteroids. Dull mentality has been noted. The affected individuals appear normal after birth, except for small testes. Most characteristic features become evident at adolescence as hypogonadism, gynecomastia, incomplete virilization with variable eunuchoidism, and dull mentality. Without testosterone therapy, most adult patients may become obese. Occasional abnormalities may include cryptorchidism, hypospadias, ataxia, scoliosis during adolescence, and diabetes mellitus in adulthood.
  Source - Diseases Database
• Klinefelter syndrome: syndrome in males that is characterized by small testes and long legs and enlarged breasts and reduced sperm production and mental retardation; a genetic defect in which an extra X chromosome (XXY) is present in the male.
  Source - WordNet 2.1

Ophanet, a consortium of European partners, currently defines a condition rare when it affects 1 person per 2,000. They list Klinefelter syndrome as a "rare disease".
Source - Orphanet

Klinefelter syndrome: Introduction

Types of Klinefelter syndrome:

Types of Klinefelter syndrome:

• XXXY syndrome
• more types...»

Broader types of Klinefelter syndrome:

• Sex chromosome conditions
• Intersex conditions
• Y Chromosome Disorders
• X Chromosome Disorders
• more types...»

How many people get Klinefelter syndrome?

Prevalance of Klinefelter syndrome: 1 per 500 - 1,000 males are affected by Klinefelter syndrome, Genetics Home Reference website
Prevalance Rate of Klinefelter syndrome: approx 1 in 500 or 0.20% or 544,000 people in USA [about data]
Incidence (annual) of Klinefelter syndrome: 1-in-500 to 1-in-1000 male births (NIDCD)
Incidence Rate of Klinefelter syndrome: approx 1 in 68,000 or 0.00% or 4,000 people in USA [about data]

Who gets Klinefelter syndrome?

Gender Profile for Klinefelter syndrome: Males only.

How serious is Klinefelter syndrome?

Complications of Klinefelter syndrome: see complications of Klinefelter syndrome

What causes Klinefelter syndrome?

Causes of Klinefelter syndrome: see causes of Klinefelter syndrome

What are the symptoms of Klinefelter syndrome?

Symptoms of Klinefelter syndrome: see symptoms of Klinefelter syndrome

Complications of Klinefelter syndrome: see complications of Klinefelter syndrome

Can anyone else get Klinefelter syndrome?

Inheritance of genetic conditions: see details in inheritance of genetic diseases.

Klinefelter syndrome: Testing

Diagnostic testing: see tests for Klinefelter syndrome.

Misdiagnosis: see misdiagnosis and Klinefelter syndrome.

How is it treated?

Treatments for Klinefelter syndrome: see treatments for Klinefelter syndrome
Research for Klinefelter syndrome: see research for Klinefelter syndrome

Organs Affected by Klinefelter syndrome:

Organs and body systems related to Klinefelter syndrome include:

• Chromosome
• X chromosome
• Y chromosome
• Sex chromosomes

Name and Aliases of Klinefelter syndrome

Main name of condition: Klinefelter syndrome

Class of Condition for Klinefelter syndrome: genetic sex chromosomal

Other names or spellings for Klinefelter syndrome:

XXY males, XXY syndrome, 47,XXY, XXY trisomy

XXY syndrome Source - Diseases Database

Klinefelter's syndrome, Klinefelter syndrome, XXY-syndrome
Source - WordNet 2.1

Research the causes of these diseases that are similar to, or related to, Klinefelter syndrome:

• XXY male
• XXY syndrome
• XXXY syndrome
• XXYY syndrome
• XXXXY syndrome
• XXXYY syndrome
• Genotype XXY
• Hypogonadism
• Gynecomastia
• Elevated urinary gonadotropins
• Androgen deficiency
• Decreased libido
• Systemic lupus erythematosus
• Rheumatoid arthritis
• Sjögren syndrome
• Mental retardation
• Infertility
• Erectile dysfunction

 » Next page: Online Medical Textbooks for Klinefelter syndrome

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