The Parents of a Child with Unusual Disease Symptoms Take

The parents of a child with unusual disease symptoms take the child to a doctor for help. The doctor suspects that the condition might have a genetic basis. She recommends that the child be taken to a specialty clinic where physicians and staff members are trained to diagnose genetic diseases and counsel parents. Ultimately, the child is diagnosed with a rare recessively inherited disease. The parents are tested for the gene, and both are found to be heterozygous. The parents are expecting another child and ask about a test to determine if this child may carry the disease. All but one of these tests may detect genetic disorders in the unborn child. Choose the EXCEPTION.

A) chorionic villus sampling
B) pedigree analysis
C) blood tests to measure levels of alpha-fetoprotein
D) amniocentesis