One of two major forms of a human condition called neurofibromatosis (NF 1)is inherited as a dominant gene, although it may range from mildly to very severely expressed. If a young child is the first in her family to be diagnosed, which of the following is the best explanation?
A) The mother carries the gene but does not express it at all.
B) One of the parents has very mild expression of the gene.
C) The condition skipped a generation in the family.
D) The child has a different allele of the gene than the parents.

Question

Quizplus · Accepted Answer

Since the condition is inherited as a dominant gene, it means that if a parent has it, there is a 50% chance of passing it on to their child. Therefore, one of the parents must have the gene, but with very mild expression, making it difficult to diagnose until their child is born with a more severe expression of the gene.

One of Two Major Forms of a Human Condition Called