What is the result of nondisjunction of sex chromosomes in males?

Nondisjunction of sex chromosomes in males typically leads to Klinefelter syndrome, which is characterized by the presence of an extra X chromosome in males, resulting in a karyotype of XXY, among other variations. This genetic anomaly occurs when the X and Y chromosomes fail to separate properly during meiosis, leading to gametes with an abnormal number of sex chromosomes. When fertilization occurs with one of these gametes, an individual typically presents with Klinefelter syndrome.

This condition often results in features such as tall stature, gynecomastia (development of breast tissue), and reduced fertility. Individuals may also experience learning difficulties and various psychosocial challenges. The impact on secondary sexual characteristics and hormone levels can vary widely among individuals with Klinefelter syndrome, but understanding that nondisjunction directly contributes to this genetic condition is central to recognizing the implications of chromosomal abnormalities.

The other conditions listed are associated with different types or mechanisms of chromosomal abnormalities that do not arise from nondisjunction in males. Turner syndrome is related to a missing or malformed X chromosome in females. Triple X syndrome involves an extra X chromosome in females. Down syndrome is caused by an extra copy of chromosome 21 and is not related to sex chromosome nond