NM_000352.6:c.4477C>T
Variant summary
Our verdict is Pathogenic. The variant received 14 ACMG points: 14P and 0B. PM5PP3_StrongPP5_Very_Strong
The NM_000352.6(ABCC8):c.4477C>T(p.Arg1493Trp) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000062 in 1,613,948 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 13/22 in silico tools predict a damaging outcome for this variant. Variant has been reported in ClinVar as Pathogenic (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R1493Q) has been classified as Likely pathogenic.
Frequency
Consequence
NM_000352.6 missense
Scores
Clinical Significance
Conservation
Publications
- hyperinsulinemic hypoglycemia, familial, 1Inheritance: AD, AR, SD Classification: DEFINITIVE, STRONG Submitted by: Ambry Genetics, Illumina, Genomics England PanelApp, Labcorp Genetics (formerly Invitae)
- diabetes mellitus, permanent neonatal 3Inheritance: AR, SD, AD Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), Genomics England PanelApp, Ambry Genetics
- familial hyperinsulinismInheritance: AR Classification: DEFINITIVE Submitted by: Myriad Women’s Health
- diabetes mellitusInheritance: SD Classification: DEFINITIVE Submitted by: Ambry Genetics
- monogenic diabetesInheritance: SD Classification: DEFINITIVE Submitted by: ClinGen
- diabetes mellitus, noninsulin-dependentInheritance: AD Classification: STRONG Submitted by: Genomics England PanelApp
- hypoglycemia, leucine-inducedInheritance: AD Classification: STRONG Submitted by: Genomics England PanelApp
- transient neonatal diabetes mellitusInheritance: AD Classification: STRONG, SUPPORTIVE Submitted by: Orphanet, Genomics England PanelApp
- permanent neonatal diabetes mellitusInheritance: AR, AD Classification: STRONG, SUPPORTIVE Submitted by: Genomics England PanelApp, Orphanet
- diabetes mellitus, transient neonatal, 2Inheritance: Unknown, AD Classification: STRONG Submitted by: Genomics England PanelApp, Labcorp Genetics (formerly Invitae)
- pulmonary arterial hypertensionInheritance: AD Classification: MODERATE Submitted by: ClinGen
- autosomal dominant hyperinsulinism due to SUR1 deficiencyInheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
- DEND syndromeInheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
- diazoxide-resistant focal hyperinsulinism due to SUR1 deficiencyInheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
- maturity-onset diabetes of the youngInheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
- autosomal recessive hyperinsulinism due to SUR1 deficiencyInheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
- type 2 diabetes mellitusInheritance: AD Classification: LIMITED Submitted by: Labcorp Genetics (formerly Invitae)
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ACMG classification
Our verdict: Pathogenic. The variant received 14 ACMG points.
Transcripts
RefSeq
Ensembl
Frequencies
GnomAD3 genomes AF: 0.00000657 AC: 1AN: 152220Hom.: 0 Cov.: 33 show subpopulations
GnomAD2 exomes AF: 0.0000159 AC: 4AN: 251370 AF XY: 0.00 show subpopulations
GnomAD4 exome AF: 0.00000616 AC: 9AN: 1461728Hom.: 0 Cov.: 32 AF XY: 0.00000413 AC XY: 3AN XY: 727182 show subpopulations
Age Distribution
GnomAD4 genome AF: 0.00000657 AC: 1AN: 152220Hom.: 0 Cov.: 33 AF XY: 0.00 AC XY: 0AN XY: 74368 show subpopulations
ClinVar
Submissions by phenotype
Hyperinsulinemic hypoglycemia, familial, 1 Pathogenic:4Other:1
This variant is found to be a potent moderate impact, deleterious variant with a CADD score of 29.3 and sufficient scientific evidence to support gene-disease correlation. This is found more frequently in congenital Hyperinsulinism cases as per recent evidence as well. However, since this is not a high impact variant and has limited evidence, this variant is reclassified as Uncertain risk allele only. -
The p.Arg1493Trp variant in ABCC8 has been reported in at least 9 individuals with hyperinsulinemic hypoglycemia (PMID: 30186238, 33688939, 10202168, 10426386, 19475716, 9769320, 15579781), segregated with disease in 2 affected relatives from 2 families (PMID: 19475716), and has been identified in 0.003% (1/30616) of South Asian chromosomes by the Genome Aggregation Database (gnomAD, http://gnomad.broadinstitute.org; dbSNP rs28936371). Although this variant has been seen in the general population in a heterozygous state, its frequency is low enough to be consistent with a recessive carrier frequency. This variant has also been reported in ClinVar (Variation ID#: 9096) and has been interpreted as pathogenic or likely pathogenic by multiple sources. Of the 9 affected individuals, at least 4 were compound heterozygotes that carried a reported pathogenic variants in trans, which increases the likelihood that the p.Arg1493Trp variant is pathogenic (PMID: 30186238, 9769320). In vitro functional studies provide some evidence that the p.Arg1493Trp variant may slightly impact protein function (PMID: 15579781). However, these types of assays may not accurately represent biological function. Computational prediction tools and conservation analyses suggest that this variant may impact the protein, though this information is not predictive enough to determine pathogenicity. In summary, this variant meets criteria to be classified as pathogenic for autosomal recessive hyperinsulinemic hypoglycemia. ACMG/AMP Criteria applied: PM3_very-strong, PP3, PP2_supporting, PS3_supporting, PP1 (Richards 2015). -
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This submission and the accompanying classification are no longer maintained by the submitter. For more information on current observations and classification, please contact variantquestions@myriad.com. -
not provided Pathogenic:2
This sequence change replaces arginine, which is basic and polar, with tryptophan, which is neutral and slightly polar, at codon 1493 of the ABCC8 protein (p.Arg1493Trp). This variant is present in population databases (rs28936371, gnomAD 0.003%). This missense change has been observed in individuals with autosomal recessive diffuse or focal hyperinsulinism (PMID: 9769320, 15579781, 30186238). This variant is also known as R1494W. ClinVar contains an entry for this variant (Variation ID: 9096). 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 with a positive predictive value of 95%. Experimental studies have shown that this missense change affects ABCC8 function (PMID: 15579781). This variant disrupts the p.Arg1493 amino acid residue in ABCC8. Other variant(s) that disrupt this residue have been observed in individuals with ABCC8-related conditions (PMID: 10426386), which suggests that this may be a clinically significant amino acid residue. For these reasons, this variant has been classified as Pathogenic. -
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Type 2 diabetes mellitus Pathogenic:1
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Hereditary hyperinsulinism Pathogenic:1
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Type 2 diabetes mellitus;C0271714:Leucine-induced hypoglycemia;C1835887:Diabetes mellitus, transient neonatal, 2;C2931832:Hyperinsulinemic hypoglycemia, familial, 1;C5394303:Diabetes mellitus, permanent neonatal 3 Pathogenic:1
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Diabetes mellitus, transient neonatal, 2 Other:1
This variant is found to be a potent moderate impact, deleterious variant with a CADD score of 29.3 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. -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at