A potential molecular target for morphological defects of fetal alcohol syndrome: Kir2.1

Fetal alcohol spectrum disorder (FASD) is a developmental disorder that affects up to 0.2% of births. FASD comprises severe cognitive and structural birth defects including cleft lip/palate, small jaw, wide-set eyes, dental abnormalities, digit abnormalities, small head, and short stature. Strict counseling guidelines stress abstaining from alcohol during pregnancy, but the prevalence of FASD persists. The lack of a convincing molecular target has hindered FASD research and treatment. Interestingly, mutations in an inwardly rectifying potassium channel, Kir2.1, cause a similar constellation of birth defects as in FASD. In other words, FASD phenocopies the traits conveyed by Kir2.1 mutations. Furthermore, alcohol directly binds to and modulates Kir2.1. Substantial evidence now suggests that alcohol targets Kir2.1 to cause the birth defects associated with FASD. This review compiles clinical, genetic, biochemical, electrophysiological, and molecular evidence that identifies Kir2.1 as a molecular target for FASD development and possibly therapeutic treatment.