09-07-2009, 01:44 AM
The parents of a 6-month-old child who was normal at birth bring her into the clinic. Since their emigration to the
U.S. from Eastern Europe soon after her birth, the child has developed diminished responsiveness, progressive
blindness and deafness, and recently, seizures. Serum levels of which of the following compounds would be
expected to be decreased in both of the parents?
A. Dystrophin
B. Hexosaminidase A
C. Hypoxanthine-guanine phosphoribosyltransferase (HGPRT)
D. Phenylalanine hydroxylase
E. Vitamin D3