Question

In assessing a patient with osteogenesis imperfecta, a history of bone fractures, as well as blue sclerae, are noted. These findings are an example of

A. allelic heterogeneity
B. gain-of-function mutation
C. locus heterogeneity
D. multiple mutations
E. pleiotropy

Answer 1

The presentation of bone fractures and blue sclerae in a patient with osteogenesis imperfecta is an example of pleiotropy, where one gene affects multiple traits due to defects in collagen production.

Step-by-step explanation:

In the case of a patient with osteogenesis imperfecta (OI) who presents with a history of bone fractures as well as blue sclerae, these findings are an example of pleiotropy. Pleiotropy occurs when one gene influences multiple phenotypic traits, which is what happens in OI due to mutations affecting collagen production. The mutation in the genes responsible for collagen production leads to the various symptoms associated with OI, such as brittle bones, blue sclerae, and in severe cases, additional issues like curvature of the spine and breathing difficulties due to compressed lungs.