Heterozygosity and localisation of normal allelic fragments for an alpha 1-antitrypsin homologous sequence.

Approximately 10 kb downstream of the alpha 1-antitrypsin (AAT) gene is a homologous sequence. Two polymorphisms detected with the restriction enzymes BglII and EcoRI have been reported previously. We describe two additional polymorphisms with the restriction endonucleases TaqI and HindIII and, for all four restriction enzymes, we have mapped the fragments corresponding to the normal alleles in a cosmid clone.