Notably, rs2471083 is located 105 kb upstream of the imprinted gene KCNK9. Mutations in this potassium channel gene cause Birk-Barel syndrome, a maternally transmitted syndrome of mental retardation, hypotonia, and unique dysmorphism, resulting from genomic-imprinting [11]. This evidence concerns the gene KCNK9 and Birk-Barel syndrome.