Mosaicism

Question 1

_____ refers to the situation that develops when a genetic abnormality arises during mitosis, post - fertilization.

Answer 1

Mosaicism

Question 2

T/F. Mosaicism results in the individual possessing both a normal cell line & a genetically abnormal cell line. A clinical consequence is that only some of that individual’s cells may exhibit the phenotypic characteristics of a particular genetic condition.

Answer 2

True.

Question 3

T/F. Mosaicism can appear to affect only the gonads, such that a phenotypically healthy individual may possess a genetic abnormality that is present in a proportion of his or her germ cells.

Answer 3

True. Gonadal Mosaisism

Question 3

T/F. The mosaicism may, of course, also be present in the gonads w/ the consequence that the off spring could inherit the mutation. The mutation would then be present in all of the child ’ s cells.

Question 3

A conditions called ___ is a result of mosaicism and the clinical features are visible only in certain parts of the body.

Answer 3

segmental neurofibromatosis type 1 (segmental NF1)

Question 4

The result of such ‘ gonadal mosaicism ’ is that a genetic condition such as ____ or ____ may occur in more than one of the children of a clinically unaffected individual.

Answer 4

Tuberous sclerosis; Duchenne muscular dystrophy