title: Twinning as a heterozygous advantage for alpha1-antitrypsin deficiency.
mesh_terms: D000328:Adult; D002648:Child; D005260:Female; D005787:Gene Frequency; D005838:Genotype; D006579:Heterozygote; D006801:Humans; D008297:Male; D010290:Parents; D010641:Phenotype; D011247:Pregnancy; D011272:Pregnancy, Multiple; D014427:Twins; D000515:alpha 1-Antitrypsin / Q000097:blood / Q000235:genetics; D019896:alpha 1-Antitrypsin Deficiency
chemical_list: D000515:alpha 1-Antitrypsin