Klinefelter syndrome
Pronunciation: KLINE-fel-ter SIN-drome
Chromosomal condition in males causing tall stature, delayed puberty, and reduced testosterone production.
Full Definition
A genetic condition affecting males caused by the presence of one or more extra X chromosomes (most commonly 47,XXY), occurring in approximately 1 in 650 male births. Klinefelter syndrome typically presents with tall stature, delayed or incomplete puberty, small testes, gynecomastia, and infertility. Many affected individuals also experience learning difficulties and behavioral challenges. Testosterone replacement therapy is usually required to induce and maintain masculine secondary sexual characteristics. Early diagnosis allows for appropriate hormone replacement and support services to optimize outcomes.
Usage
Usage note: Include karyotype results when available; avoid possessive form 'Klinefelter's'.
In Context
- "The karyotype revealed 47,XXY, confirming the diagnosis of Klinefelter syndrome." — Genetic test result
- "Boys with Klinefelter syndrome typically require testosterone replacement therapy during adolescence." — Treatment guideline