Question

Tay-Sach disease is due to

• A. Sex-linked recessive gene
• B. Sex-linked dominant gene
• C. Autosomal dominant gene
• D. Autosomal recessive gene

Answer 1

The correct option is D Autosomal recessive gene

Tay-Sachs disease is caused by defective enzyme hexoseaminidase-A which serves in lipid metabolism. Trait often skips generations, most affected individuals have unaffected parents but if both parents are affected, all children should be affected. This means that disease is governed by recessive; options B and C are wrong. Equal number of affected males and females are found which means that disease is governed by autosomal gene and is inherited independent of sex of individual. If it was a sex linked gene, it’s inheritance would depend on sex of individual; this makes options A and B wrong. Correct answer is D.