Question

Epicanthus skin fold above the eyes and transverse palmar crease are typical symptoms of
A) Cri-du-chat
B) Klinefelter’s syndrome
C) Down’s syndrome
D) Turner’s syndrome

Answer 1

Hint: It is a chromosomal disorder defined by the existence of an additional copy of genetic material on chromosome 21.

Complete answer:
First we should know about genetic disorders to answer this question. A genetic disease is a condition caused by a deviation in the DNA sequence away from the normal sequence. It is a disorder that arises as a consequence of a DNA mutation. Several distinct genetic disorders exist.

Now, let us find the solution from the options-
> Cri-du - chat syndrome is caused due to loss of half of the short arm of chromosome 5, and it characterised by mewing as the cry of the newborn. Thus, the option A is incorrect.
> Klinefelter's syndrome is caused by the development of one or two extra X-chromosome copies in males. There are 44 + XXY /44+XXXY / 44+XXXXY chromosomes in the infected male. Some feminine characters are created in man due to the presence of an additional X-chromosome copy. Thus, the option B is incorrect.
> Trisomy-21, i.e., the occurrence of chromosome 21 in three copies, is Down syndrome. The afflicted people suffer from congenital cardiac defects with a very high chance of acute leukaemia and are mentally retarded. They are short stature and have a broad, small skull; hyper joint flexibility; and excess skin on the neck back, epicanthal fold of the skin above the eyes and transverse palmar crease.
> Turner syndrome is a monosomy caused in females occurs due to the lack of one copy of the X-chromosome. These women only bear a single copy of the genes found on X-chromosomes and are thus sterile women with an undeveloped breast. Thus, the option D is incorrect.

Thus, the correct answer is option D Down’s Syndrome

Note: A skin fold protecting the medial angle of the eye is the epicanthal fold or epicanthus. The fold can be scarcely visible to a well-developed fold. Typically, it is most pronounced during childhood. With maturity, as the nose bridge grows more height, it draws the skin away from the eye, lowering and reshaping the fold.