The client is 34 years old and has been diagnosed with COPD as a result of being homozygous for a mutation of the alpha1-antitrypsin (AAT) gene alleles. His wife has two normal AAT gene alleles

Question

He is concerned that his two children may develop this problem. What is your best response? A. "Because neither of your parents have COPD and your wife does not have the abnormal gene alleles, your children will not be affected."
B. "Because your wife is not affected nor is or a carrier, your children will have normal levels of AAT and their risk is the same as for the general population."
C. "Because you have the mutations and your wife does not, your son will be at an increased risk for developing COPD but your daughter will only be a carrier."
D. "Because both of your AAT gene alleles are mutated, your children will each have one abnormal gene and their risk for COPD is only increased if they smoke or are chronically exposed to other precipitating factors."

Answer 1

D
The production of sufficient quantities of AAT is dependent on the inheritance of a pair of nor-mal gene alleles. The AAT gene is recessive. Thus, if one of the pair of gene alleles is missing or mutated and the other gene allele is normal, the person makes enough AAT to prevent COPD unless there is significant exposure to cigarette smoke and other precipitating factors. This person, however, is a carrier for AAT deficiency. If both alleles of the gene are mutated, COPD develops at a fairly young age, even when the person is not exposed to cigarette smoke or other irritants.