NALCN and congenital contractures of the limbs and face, hypotonia, and developmental delay: Specific germline mutations in NALCN are known to result in two neurological disorders; de novo heterozygous mutations to congenital contractures of the limbs and face, hypotonia, and developmental delay (CLIFAHDD [MIM 616266]), and biallelic mutations to infantile hypotonia with psychomotor retardation and characteristic facies 1 (IHPRF1 [MIM 615419]) documented in Online Mendelian Inheritance in Man (OMIM®) [41].