Question

Due to nondisjunction of chromosomes during spermatogenesis some sperms carry both sex chromosomes$(22A+XY)$ while others do not carry any sex chromosome $(22A+O)$. If these sperms fertilize normal eggs $(22A+X)$, what type of genetic disorders appear among the offspring.

• A. Turner's syndrome and Klinefelter's syndrome
• B. Down's syndrome and Klinefelter's syndrome
• C. Down's syndrome and Turner's syndrome
• D. Down's syndrome and Cri-du-chat syndrome

Answer 1

The correct option is A Turner's syndrome and Klinefelter's syndrome

Turner's syndrome occurs due to monosomy i.e., (2n - 1). It is formed by the union of an abnormal egg and a normal X sperm or a normal egg and an abnormal sperm. The individual has 2n = 45 chromosomes (44 + X), instead of 46. Such persons are sterile females who have rudimentary ovaries, undeveloped breasts, small uterus, puffy fingers, short stature (less than 5 feet), webbed neck, abnormal intelligence, cardiovascular abnormalities and hearing impairment.

Klinefelter's syndrome is due to trisomy of sex (X) chromosomes. It is formed by the union of an abnormal XX egg and normal Y sperm or normal X egg and abnormal XY sperm. The individual has 47 chromosomes (44 + XXY). Such persons are sterile males (called feminised male) with undeveloped testes, mental retardation, female like sparse body hair, and knock knees, long limbs and with some female characteristics such as feminine pitched voice and enlarged breasts (gynaecomastia).

So, the correct answer is 'Turner's syndrome and Klinefelter's syndrome'.