Our verdict is Uncertain significance. Variant got 3 ACMG points: 4P and 1B. PM1PM2BP4
The NM_000352.6(ABCC8):c.3517G>A(p.Val1173Met) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000161 in 1,613,952 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 14/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★).
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 Uncertain_significance. Variant got 3 ACMG points.
PM1
In a domain ABC transmembrane type-1 2 (size 294) in uniprot entity ABCC8_HUMAN there are 22 pathogenic changes around while only 2 benign (92%) in NM_000352.6
PM2
Very rare variant in population databases, with high coverage;
BP4
Computational evidence support a benign effect (MetaRNN=0.3348059).
Centre for Mendelian Genomics, University Medical Centre Ljubljana
Jan 01, 2017
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not specified Uncertain:1
Uncertain significance, criteria provided, single submitter
clinical testing
Women's Health and Genetics/Laboratory Corporation of America, LabCorp
May 15, 2024
Variant summary: ABCC8 c.3517G>A (p.Val1173Met) results in a conservative amino acid change located in the ABC transporter type 1, transmembrane domain (IPR011527) of the encoded protein sequence. Four of five in-silico tools predict a benign effect of the variant on protein function. The variant allele was found at a frequency of 1.2e-05 in 251412 control chromosomes (gnomAD). The available data on variant occurrences in the general population are insufficient to allow any conclusion about variant significance. c.3517G>A has been reported in the literature in at-least one MODY diagnosed patient that also had a co-occurrence in GCK c.943C>T (Yalcintepe_2021) as well as individuals not affected with diabetes (Billings_2022). These reports do not provide unequivocal conclusions about association of the variant with Neonatal Diabetes Mellitus. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. The following publications have been ascertained in the context of this evaluation (PMID: 36208030, 33565752). ClinVar contains an entry for this variant (Variation ID: 35609). Based on the evidence outlined above, the variant was classified as uncertain significance. -
Inborn genetic diseases Uncertain:1
Uncertain significance, criteria provided, single submitter
clinical testing
Ambry Genetics
Nov 10, 2022
The c.3517G>A (p.V1173M) alteration is located in exon 28 (coding exon 28) of the ABCC8 gene. This alteration results from a G to A substitution at nucleotide position 3517, causing the valine (V) at amino acid position 1173 to be replaced by a methionine (M). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -
Monogenic diabetes Uncertain:1
Uncertain significance, criteria provided, single submitter
curation
Broad Center for Mendelian Genomics, Broad Institute of MIT and Harvard
Jan 22, 2020
The p.Val1173Met variant in ABCC8 has been reported in 1 individual with Monogenic Diabetes in ClinVar (Variation ID: 35609), and has been identified in 0.003098% (4/129110) of European (non-Finnish) chromosomes by the Genome Aggregation Database (gnomAD, http://gnomad.broadinstitute.org; dbSNP rs141322087). Although this variant has been seen in the general population, its frequency is low enough to be consistent with a carrier frequency. Please note that for diseases with clinical variability, or reduced penetrance, pathogenic variants may be present at a low frequency in the general population. This variant has also been reported likely pathogenic in ClinVar (Variation ID: 35609). Computational prediction tools and conservation analyses suggest that this variant may not impact the protein, though this information is not predictive enough to rule out pathogenicity. In summary, the clinical significance of the p.Val1173Met variant is uncertain. ACMG/AMP Criteria applied: PM2_Supporting, BP4 (Richards 2015). -
Maturity onset diabetes mellitus in young Uncertain:1
Uncertain significance, criteria provided, single submitter
research
Clinical Genomics, Uppaluri K&H Personalized Medicine Clinic
-
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 ( rs141322087) in MODY yet. -
Permanent neonatal diabetes mellitus Uncertain:1
Uncertain significance, criteria provided, single submitter
clinical testing
Centre for Mendelian Genomics, University Medical Centre Ljubljana
Oct 24, 2018
This variant was classified as: Uncertain significance. The following ACMG criteria were applied in classifying this variant: PM2,PP2,PP5. -
Transitory neonatal diabetes mellitus Uncertain:1
Uncertain significance, criteria provided, single submitter
research
Clinical Genomics, Uppaluri K&H Personalized Medicine Clinic
-
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 ( rs141322087) in neonatal diabetes yet. -