Alpha 1 Antitrypsin Deficiency, Two Cases of Heterozygous S and Clayton Null Alleles

Alpha-1 antitrypsin deficiency (AATD) is a disorder that can lead to early onset lung and liver disease and is considered to be underdiagnosed. The purpose of this paper is to demonstrate the importance of early detection using genotyping of AATD by presenting two very rare cases of this disorder and to remind clinicians to maintain a high level of suspicion for this disorder. Two unrelated patients presented to different pulmonology offices in Grand Blanc, MI and were screened for AATD for different reasons. Testing for both patients included alpha-1 antitrypsin enzyme levels, phenotyping, and genotyping. Both individuals were heterozygotes for S allele and Q0Clayton allele. The Q0Clayton allele is a very rare Null allele that is defined this way because these individuals do not produce any alpha-1 antitrypsin. These cases highlight the need for early testing of patients with risk factors for AATD. Also demonstrated is the need to include genotype testing to accurately identify the risk of developing emphysema and cirrhosis. Lower morbidity and mortality may result if AATD is detected early.