Our verdict is Pathogenic. Variant got 11 ACMG points: 11P and 0B. PM1PM2PM5PP3_StrongPP5
The NM_000352.6(ABCC8):c.2522G>A(p.Arg841Gln) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000248 in 1,611,924 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R841G) has been classified as Likely 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 11 ACMG points.
PM1
In a domain ABC transporter 1 (size 250) in uniprot entity ABCC8_HUMAN there are 14 pathogenic changes around while only 5 benign (74%) 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 chrnull-null-null-null is described in UniProt as null.
PP3
MetaRNN computational evidence supports a deleterious effect, 0.989
PP5
Variant 11-17412700-C-T is Pathogenic according to our data. Variant chr11-17412700-C-T is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 554121.We mark this variant Likely_pathogenic, oryginal submissions are: {Uncertain_significance=1, Pathogenic=1, Likely_pathogenic=3, Uncertain_risk_allele=2}.
Likely pathogenic, criteria provided, single submitter
clinical testing
Diagnostics Services (NGS), CSIR - Centre For Cellular And Molecular Biology
Jan 13, 2020
The NM_000352.6:c.2522G>A variant is not present in publicly available database, Exome Variant Server (EVS). The variant is present in 1000 Genomes, Exome Aggregation Consortium (ExAC), Genome Aggregation Database (gnomAD) and dbSNP at a very low frequency (MAF<=0.0001) in heterozygous state. The variant is not present in our in-house exome database. The variant was earlier reported to Human Genome Mutation database (HGMD ID: CM112697) in other similarly affected individuals [Banerjee et al., Eur J Endocrinol 2011]. In-silico pathogenicity prediction programs like SIFT, Polyphen2, MutationTaster2, CADD etc. predicted this variant as likely deleterious. Hence as per ACMG guidelines the variant has been classified as likely pathogenic. -
Uncertain significance, flagged submission
clinical testing
Counsyl
Sep 26, 2017
- -
Likely pathogenic, criteria provided, single submitter
clinical testing
Institute of Human Genetics, University of Leipzig Medical Center
Jan 01, 2019
- -
Type 2 diabetes mellitus Pathogenic:1
Likely pathogenic, criteria provided, single submitter
Likely pathogenic, criteria provided, single submitter
clinical testing
Fulgent Genetics, Fulgent Genetics
Mar 01, 2024
- -
not provided Pathogenic:1
Pathogenic, criteria provided, single submitter
clinical testing
Labcorp Genetics (formerly Invitae), Labcorp
May 13, 2022
This missense change has been observed in individuals with clinical features of autosomal recessive diffuse or paternally inherited focal hyperinsulinism (PMID: 21378087, 24686051). This sequence change replaces arginine, which is basic and polar, with glutamine, which is neutral and polar, at codon 841 of the ABCC8 protein (p.Arg841Gln). This variant is not present in population databases (gnomAD no frequency). This variant is also known as c.2525G>A p.Arg842Gln. ClinVar contains an entry for this variant (Variation ID: 554121). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is expected to disrupt ABCC8 protein function. This variant disrupts the p.Arg841 amino acid residue in ABCC8. Other variant(s) that disrupt this residue have been observed in individuals with ABCC8-related conditions (PMID: 11395395, 32202736), which suggests that this may be a clinically significant amino acid residue. For these reasons, this variant has been classified as Pathogenic. -
Neonatal diabetes mellitus Other:1
Uncertain risk allele, criteria provided, single submitter
research
Clinical Genomics, Uppaluri K&H Personalized Medicine Clinic
May 27, 2024
This variant is found to be a potent moderate impact, variant with a CADD score of 29.8 and sufficient scientific evidence of gene-disease correlation. However, since this is not a high impact variant and no variant evidence, this variant is reclassified as Uncertain risk allele. -
Maturity onset diabetes mellitus in young Other:1
Uncertain risk allele, criteria provided, single submitter
research
Clinical Genomics, Uppaluri K&H Personalized Medicine Clinic
May 29, 2024
Mutations in ABCC8 gene are associated with both neonatal diabetes mellitus as well as MODY. Patients with this mutation may have a better response to sulfonylureas. However, no sufficient evidence is found to ascertain the role of this particular variant ( rs547150342) in MODY yet. This variant is found to be a potent moderate impact, deleterious variant with a CADD score of 29.8 and sufficient scientific evidence to support gene-disease correlation. However, since this is not a high impact variant and has no variant evidence, this variant is reclassified as Uncertain Risk Allele -