Question

Scientists are researching a large family, many of whose members have Jackson-Weiss Syndrome, a disease that causes bone problems. The scientists noticed that every person with Jackson-Weiss Syndrome had a parent who also had the disease. What is the most likely conclusion that can be made about Jackson-Weiss Syndrome? A. It is not a genetic disease. B. It is a genetic disease caused by a recessive allele. C. It is a genetic disease caused by a dominant allele D. It is a genetic disease caused by a mutation in the child's DNA.

Answer 1

The right answer is C.

A genetic disease is called autosomal dominant transmission when :

* The morbid allele ("sick" version, mutated of the gene in question) is on a non-sexual chromosome (neither X nor Y).

* The presence of a single morbid allele is sufficient for the disease to express itself.

The morbid allele is transmitted by either the father or the mother (or both, if they have the same inherited autosomal dominant genetic disease). Anyone with one of their affected parents is affected.

Jackson-Weiss syndrome is indeed an autosomal dominant disease characterized by a malformation of the feet, craniosynostosis of varying degrees, facial abnormalities, enlargement of the big toes and normal hands.