NEET BIOLOGY

Detailed explanation-1: -Usually, a female baby has 2 X chromosomes (XX) and a male has 1 X and 1 Y (XY). But in Klinefelter syndrome, a boy is born with an extra copy of the X chromosome (XXY). The X chromosome is not a “female” chromosome and is present in everyone. The presence of a Y chromosome denotes male sex.

Detailed explanation-2: -Klinefelter Syndrome (47, XXY) is a chromosomal variation in males in which one extra X chromosome is present, resulting in a 47, XXY karyotype. The extra X chromosome typically affects physical, neurodevelopmental, behavioral, and neurocognitive functioning.

Detailed explanation-3: -Diagnosis is by a chromosomal analysis, but most of those affected are not diagnosed within their lifetime. There are 47 chromosomes, instead of the usual 46, giving a 47, XYY karyotype. Treatment may include speech therapy or extra help with schoolwork, however outcomes are generally positive.

Detailed explanation-4: -Most often, boys and men with Klinefelter syndrome have the usual X and Y chromosomes, plus one extra X chromosome, for a total of 47 chromosomes (47, XXY).

Detailed explanation-5: -The most common karyotype is 47, XXY, which accounts for 80-90% of all cases. Mosaicism (46, XY/47, XXY) is observed in about 10% of cases. Other variant karyotypes, including 48, XXYY; 48, XXXY; 49, XXXYY; and 49, XXXXY, are rare.