Our verdict is Uncertain significance. Variant got 0 ACMG points: 4P and 4B. PM1PM2BP4_Strong
The NM_000352.6(ABCC8):c.4692G>T(p.Lys1564Asn) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,844 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 16/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (no stars).
ABCC8 (HGNC:59): (ATP binding cassette subfamily C member 8) The protein encoded by this gene is a member of the superfamily of ATP-binding cassette (ABC) transporters. ABC proteins transport various molecules across extra- and intra-cellular membranes. ABC genes are divided into seven distinct subfamilies (ABC1, MDR/TAP, MRP, ALD, OABP, GCN20, White). This protein is a member of the MRP subfamily which is involved in multi-drug resistance. This protein functions as a modulator of ATP-sensitive potassium channels and insulin release. Mutations in the ABCC8 gene and deficiencies in the encoded protein have been observed in patients with hyperinsulinemic hypoglycemia of infancy, an autosomal recessive disorder of unregulated and high insulin secretion. Mutations have also been associated with non-insulin-dependent diabetes mellitus type II, an autosomal dominant disease of defective insulin secretion. Alternatively spliced transcript variants have been found for this gene. [provided by RefSeq, Jul 2020]
Uncertain significance, no assertion criteria provided
clinical testing
PreventionGenetics, part of Exact Sciences
Jun 14, 2024
The ABCC8 c.4692G>T variant is predicted to result in the amino acid substitution p.Lys1564Asn. To our knowledge, this variant has not been reported in the literature or in a large population database, indicating this variant is rare. However, a different variant affecting this amino acid has been reported as a variant of uncertain significance in a cohort of patients who underwent testing for dyslipidemia (p.Lys1564Glu, Dron et al. 2020. PubMed ID: 32041611). At this time, the clinical significance of the c.4692G>T variant is uncertain due to the absence of conclusive functional and genetic evidence. -