Question

Absence of one sex chromosome causes
A. Turner’s syndrome
B. Kilnefelter’s syndrome
C. Down’s syndrome
D. Tay- sachs syndrome

Answer 1

Hint: Syndrome is the group of signs or changes that occur in the body that are typical of an illness. Most common syndromes around the world are prader- willi syndrome, sickle cell disease, spinal muscular atrophy, Tay – Sachs disease. The word syndrome derived from Greek, which means concurrence.

Complete Answer:
Turner syndrome is the genetic condition that only affects females. The condition is caused by an abnormal chromosome and affects about one in every 2,500 baby girls, but is more common among pregnancies that do not survive to term (miscarriages and stillbirths).

Turner syndrome is caused by nondisjunction. A pair of sex chromosomes failed to separate during the formation of an egg. So, when an abnormal egg unites with normal sperm to form an embryo, that embryo may end up missing one of the sex chromosomes (X rather than XX). The abnormality is not inherited from an affected parent (not passed down from parent to child). Because women with turner syndrome are generally sterile and cannot have children.

Symptoms are turner syndrome: It affects the growth and sexual development, a low hairline at the back portion of neck, abnormalities in skeletal structure, kidney problems, etc.

Thus, the option (A) is correct.

Note: Another name of turner syndrome is Ullrich- turner syndrome, TS, monosomy X. types of turner syndrome are X- chromosome monosomy. X- Chromosome mosaicism, X- chromosome defects. Dr Henry Turner discovered this syndrome in 1938.