GENERAL NOTES
APPLICATION: Detection of hereditary A1AT deficiency. Investigation of early onset emphysema; neonatal hepatits; juvenile cirrhosis; pannicultis.
INTERPRETATION: Alpha-1-antitrypsin deficiency is associated with early onset emphysema, hepatitis and cirrohosis and with panniculitis. If deficiency is documented, phenotyping should be done on proband and family. Levels of alpha-1-antitrypsin are increased in an acute phase response and this may mask a deficiency state. If there is a high clinical suspicion of A1AT deficiency, phenotyping should be performed, regardless of the A1AT level. Genetic variants with at least 100 alleles have been described; genotyping is currently available for 2 phenotypes associated with disease: S and Z. Genotyping distinguishes ZZ from Z null or SS from S null patients without the need for family studies.