Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PM1PM2PM5PP3_StrongPP5_Very_Strong
The NM_000352.6(ABCC8):c.4136G>T(p.Arg1379Leu) variant causes a missense change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Likely pathogenic (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R1379P) has been classified as Pathogenic.
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]
Verdict is Pathogenic. Variant got 18 ACMG points.
PM1
In a binding_site (size 7) in uniprot entity ABCC8_HUMAN there are 4 pathogenic changes around while only 0 benign (100%) in NM_000352.6
PM2
Very rare variant in population databases, with high coverage;
PM5
Other missense variant is known to change same aminoacid residue: Variant chr11-17395914-C-G is described in Lovd as [Pathogenic].
PP3
MetaRNN computational evidence supports a deleterious effect, 0.992
PP5
Variant 11-17395914-C-A is Pathogenic according to our data. Variant chr11-17395914-C-A is described in ClinVar as [Likely_pathogenic]. Clinvar id is 35615.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
Likely pathogenic, criteria provided, single submitter
clinical testing;curation
Women's Health and Genetics/Laboratory Corporation of America, LabCorp
Aug 18, 2011
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not provided Pathogenic:1
Pathogenic, criteria provided, single submitter
clinical testing
Genetic Services Laboratory, University of Chicago
Jul 16, 2019
DNA sequence analysis of the ABCC8 gene demonstrated a sequence change, c.4136G>T, in exon 34 that results in an amino acid change, p.Arg1379Leu. The p.Arg1379Leu change has been identified in patients with transient neonatal diabetes and family members of these individuals who were diagnosed with diabetes in adulthood (PMID: 18025464). Additionally, several other mutations affecting the same amino acid residue (p.Arg1379Cys, p.Arg1379His, p.Arg1379Pro, p.Arg1379Ser) have been reported in patients with neonatal diabetes as well as adult onset diabetes (PMIDs: 18025464, 16885549, 24622368, 25555642). The p.Arg1379Leu change is absent from large population databases such as ExAC and gnomAD. The p.Arg1379Leu change affects a highly conserved amino acid residue located in a domain of the SUR1 protein that is known to be functional. The p.Arg1379Leu substitution appears to be deleterious using several in-silico pathogenicity prediction tools (SIFT, PolyPhen2, Align GVGD, REVEL). -