In ASD1 patients, CYP11B2 variants cause complete enzyme inactivation, compromising heme-binding sites or highly conserved sites necessary for enzymatic activity, and mainly homozygous genotypes are observed, whereas in ASD2 patients CYP11B2 variants only cause partial enzyme inactivation and more complex genotypes, including double homozygosis, compound heterozygosis, and triple variants, may be observed [80]. The gene discussed is CYP11B2; the disease is atrial septal defect 2.