What is the abnormality seen in the following karyotype?
High-Yield Explanation
The above karyotype- 47, XXY, is suggestive of Klinefelter&;s syndrome in which gynecomastia and long thin limbs are seen. Klinefelter&;s syndrome: Most common sex aneuploidy in males Classically karyotype is 47,XXY, Other variants can have 48,XXXY; rarel, 49 XXXXY; or mosaics with some cells containing normal 46, XY and others 47,XXY Results from meiotic nondisjunction of sex chromosomes (mostly during 1st meiotic division) Clinical features: Dispropoionately long arms and legs Mitral valve prolapse Mental retardation; IQ: 60-80 Minor development and learning disabilities Lack of secondary sexual characteristics (due to a decrease in androgen production) Gynecomastia Higher risk of breast carcinoma Testicular dysgenesis Infeility/azoospermia Ref: Nelson textbook of pediatrics 21st edition Pgno: 671