Clinical Sciences

Question 1

In autosomal dominant inheritance, do carriers exist?

Answer 1

No, both homozygotes and heterozygotes are affected; there is no carrier state.

Question 2

Are males and females equally affected in autosomal dominant diseases?

Answer 2

Yes

Question 3

Do autosomal dominant diseases typically skip generations?

Answer 3

No, they usually appear in every generation.

Question 4

What is the recurrence risk in successive pregnancies for autosomal dominant diseases?

Answer 4

The risk remains the same for each pregnancy (50%).

Question 5

What is non-penetrance in the context of autosomal dominant diseases?

Answer 5

It’s when an individual has the abnormal gene but does not show clinical signs or symptoms.

Question 6

What is an example of non-penetrance in autosomal dominant disorders?

Answer 6

Otosclerosis, with about 40% showing non-penetrance.

Question 7

What is a spontaneous mutation in autosomal dominant inheritance?

Answer 7

A new mutation occurring in a gamete, causing the disease in a child with unaffected parents.

Question 8

What is an example of a disease often caused by spontaneous mutation in an autosomal dominant gene?

Answer 8

Achondroplasia—about 80% of cases result from new mutations.