Question

A mutation in a gene can results in a new function for the gene. The term for this type of mutation is ________.

	a.	Haplosuficiency
	b.	haploinsuficiency
	c.	gain of function
	d.	loss of function or null

Answer 1

Ans :-) option c. Gain of function.

Gain of function is a type of mutation in which the altered gene product possess a new molecular function or new pattern of gene expression. Gain of function are always dominant or semidominant.

Loss of function mutations are also called as inactivating mutation. It results in gene product having less or no function. When the allele has a complete loss of function. It is often called amorph or amorphic mutation.

Haplosufficiency occurs in situation where single copy of a functional gene is enough to maintain normal function.

Haploinsuffienciency is a situation in which the total level of gene product produced by cell is about half of normal level and that is not sufficient to permit the cell to function normally.