Polydactyly is a genetic condition where an individual has extra digits (fingers
ID: 50810 • Letter: P
Question
Polydactyly is a genetic condition where an individual has extra digits (fingers or toes). The most common form of polydactyly is caused by a dominant mutation in a gene called Sonic hedgehog (Shh). Based on this, which of the following would be true (choose all that are correct).
Individuals with two copies of "wild-type" Shh are not polydactyl.
Individuals with two copies of mutant Shh are polydactyl.
Individuals with two copies of "wild-type" Shh are polydactyl.
Individuals with one copy of mutant Shh and one "wild-type" Shh are polydactyl.
Individuals with two copies of mutant Shh are not polydactyl.
Individuals with one copy of mutant Shh and one "wild-type" Shh are not polydactyl.
()Individuals with two copies of "wild-type" Shh are not polydactyl.
()Individuals with two copies of mutant Shh are polydactyl.
()Individuals with two copies of "wild-type" Shh are polydactyl.
()Individuals with one copy of mutant Shh and one "wild-type" Shh are polydactyl.
()Individuals with two copies of mutant Shh are not polydactyl.
()Individuals with one copy of mutant Shh and one "wild-type" Shh are not polydactyl.
Explanation / Answer
Since mutation in Shh gene which is dominant in nature causes polydactyly therefore following statements will be true:
Individuals with two copies of "wild-type" Shh are not polydactyl.
Individuals with two copies of mutant Shh are polydactyl.
Individuals with one copy of mutant Shh and one "wild-type" Shh are polydactyl.