Klinefelter Syndrome

Definition: condition in which human males have an extra X chromosome “XXY syndrome”

Etiology: Nondisjunction. Nondisjunction occurs with when homologous chromosomes fail to separate.

Frequency: 1:1000

Clinical features:

- Tall height

- Abnormal body proportions (long legs, short trunk, shoulder equal to hip size)

- Small testicles

- Reduced fertility

- Abnormally large breasts (gynecomastia)

- Less than normal amount of facial and pubic hair

- Oral: taurodontism (elongated pulp chamber with short stunted roots)

Diagnosis:

- May first be diagnosed when a man seeks a physician consult due to infertility

Treatment:

- Testosterone therapy may aid in producing a more masculine appearance.

Complications:

Increased risk of:

- ADHD

- Autoimmune disorders such as SLE, Rheumatoid Arthritis, Sjogren Syndrome

- Breast cancer in men

- Depression

- Learning disabilities, including dyslexia

- Extragonadal germ cell tumor

- Lung disease

- Osteoporosis

- Varicose Veins