Racial distribution of alpha1-antitrypsin variants among junior high school students.

A survey of alpha1-antitrypsin phenotypes and serum trypsin inhibitory capacities was performed in 1,841 seventh grade junior high school students. Antitrypsin deficiency states were detected only in white subjects (3.04) per cent) and not in 461 subjects of other races or of Mexican origin. A screening level of serum trypsin inhibitory capacity at 75 per cent of normal or less included all of the deficient phenotypes, but phenotyping was necessary to eliminate a small percentage of normal and unimportant variant phenotypes from this group. It is suggested that future programs for detecting antitrypsin deficiency and for counseling students who are genetically prone to develop pulmonary emphysema be aimed primarily at white populations.