ATP-binding cassette transporter subfamily C member 8 (ABCC8) (accession number: NM_000352.4) has 17 transmembrane helices arranged in groups of five (N-terminal transmembrane domain (TMD0)), six (TMD1), and six (TMD2). Two large cytosolic loops follow TMD1 and TMD2 and contain the nucleotide-binding domains (NBDs, including NBD1 and NBD2) that are characteristic of ATP-binding cassette (ABC) proteins. The L0 linker region is located between the TMD0 and the TMD1 domains. ABCC8-NDM: ABCC8 variant-induced neonatal diabetes mellitus; Het: heterozygous; Hom: homozygous; CH: compound het; DEND: developmental delay and epilepsy syndrome; i-DEND: intermediate DEND syndrome. indicates that the variant has been demonstrated to be activating in functional studies.