Klinefelter’s Syndrome

Klinefelter’s syndrome is a genetic disease

Pathophysiology

disorder of sex chromosomes with presence of two or more X chromosomes in men

Signs and Symptoms

1) gynecomastia 2) small testes 3) azoospermia 4) infertility 5) taller than normal height 6) obesity 7) varicose veins 8) leg ulcers 9) developmental delay 10) eunuch-like body habitus 11) antisocial behavior 12) mild mental retardation 13) usually not recognized until puberty

Characteristic Test Findings

Laboratory – 1) increased plasma gonadotropins 2) decrease plasminogen activator inhibitor (causing leg ulcers) 3) decreased testosterone levels 4) increased FSH 5) increased LH

Histology/Gross Pathology

1) hyalinization of seminiferous tubules 2) presence of Barr bodies

Associated Conditions

1) social maladjustment 2) diabetes mellitus 3) thyroid malfunction 4) 20 times increased risk of breast cancer 5) increased risk of acute myelogenous leukemia 6) lymphedema 7) pulmonary disease 8) advanced maternal age

Inheritance

occurs in 1/500 males

Treatment

1) surgery for gynecomastia 2) exogenous testosterone

Tips for USMLE

1) two or more chromosomes in men 2) 20 times increased risk of breast cancer in men