[doctorF]

A woman gives birth to a child apparent achondroplasia. Two other siblings are of normal stature for their age. A genetic consultation group is asked to review the case. Both parents are 42 years old, and there is no previous family history of this condition.

What is the most likely explanation for the occurrence of this defect in this family?

a. gonadal mosaicism
b. incomplete penetrance
c. new mutation in the maternal gamete
d. new mitation in the paternal gamete
e. nonpaternity

 

[Seetal]

hmm...

could it be A??

 

[khanar]

It's new mutation

This must be new mutation but I can't figure out whether C or D is the correct answer

 

[HouseWannabe]

D, my guess is cause Achondroplasia is correlated to old paternal age.

 

[sam01]

Yeah. It is D. In achondroplasia, gene mutation increase with paternal age (fibroblast growth factor receptor gene)

 

[HouseWannabe]

Just an extra tidbit of info; both Achondroplasia AND MARFAN's Syndrome are correlated to advanced paternal age.

 

[doctorF]

yep guys d) dad is the problem here. this is a new mutation. risk increases with paternal age > 35 yo