Question

Which of the following is not related to sex chromosome $X$ or $Y$?

• A. Turners syndrome
• B. Klinefelters syndrome
• C. Downs syndrome
• D. Haemophilia and colour blindness

Answer 1

Answer: (C)

Downs syndrome or Mongolian idiocy is not related to sex chromosome $X$ or $Y$. It is due to the $1st$ trisomy of $21st$ chromosome, ie, total $47$ chromosomes. The main features are mental deficiency, short stature, round face, flaccid muscles, small ears, protruding tongue and epithelial folds over the eyes (to give Mongolian look).