rs576684889
Variant summary
Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PVS1PM2PP5_Very_Strong
The NM_000352.6(ABCC8):c.3400-1G>A variant causes a splice acceptor, intron change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000657 in 152,254 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Likely pathogenic (★★).
Frequency
Consequence
NM_000352.6 splice_acceptor, intron
Scores
Clinical Significance
Conservation
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ACMG classification
Verdict is Pathogenic. Variant got 18 ACMG points.
Transcripts
RefSeq
Ensembl
Frequencies
GnomAD3 genomes AF: 0.00000657 AC: 1AN: 152136Hom.: 0 Cov.: 33
GnomAD3 exomes AF: 0.00000425 AC: 1AN: 235136Hom.: 0 AF XY: 0.00 AC XY: 0AN XY: 126944
GnomAD4 exome Data not reliable, filtered out with message: AC0;AS_VQSR AF: 0.00 AC: 0AN: 1452786Hom.: 0 Cov.: 31 AF XY: 0.00 AC XY: 0AN XY: 722008
GnomAD4 genome AF: 0.00000657 AC: 1AN: 152254Hom.: 0 Cov.: 33 AF XY: 0.00 AC XY: 0AN XY: 74438
ClinVar
Submissions by phenotype
Hyperinsulinemic hypoglycemia, familial, 1 Pathogenic:2
The c.3400-1G>A variant in ABCC8 has been reported in 2 individuals with hyperinsulinemic hypoglycemia (PMID: 23275527, Tran et al. 2019 abstract), and has been identified in 0.006% (1/17126) of East Asian chromosomes by the Genome Aggregation Database (gnomAD, http://gnomad.broadinstitute.org; dbSNP rs576684889). 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. Of the 2 affected individuals, 1 was a compound heterozygote that carried a reported pathogenic variant in trans, which increases the likelihood that the c.3400-1G>A variant is pathogenic (PMID: 23275527). This variant is located in the 5' splice region. SpliceAI predictions indicate use of an out-of-frame cryptic splice site 55 bases from the intron-exon boundary, providing evidence that this variant may cause a frameshift and lead to a premature termination codon downstream. This alteration is then predicted to lead to a truncated or absent protein. However, this information is not predictive enough to determine pathogenicity. Loss of function of the ABCC8 gene is an established disease mechanism in autosomal recessive hyperinsulinemic hypoglycemia. In summary, this variant meets criteria to be classified as pathogenic for autosomal recessive hyperinsulinemic hypoglycemia. ACMG/AMP Criteria applied: PVS1, PM3, PM2_supporting (Richards 2015). -
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Familial hyperinsulinism Pathogenic:1
Variant summary: ABCC8 c.3400-1G>A is located in a canonical splice-site and is predicted to affect mRNA splicing resulting in a significantly altered protein due to either exon skipping, shortening, or inclusion of intronic material. Several computational tools predict a significant impact on normal splicing: Five predict the variant abolishes the canonical 3' acceptor site. However, these predictions have yet to be confirmed by functional studies. The variant allele was found at a frequency of 4.3e-06 in 235136 control chromosomes (gnomAD). c.3400-1G>A has been reported in the literature in individuals affected with Congenital Hyperinsulinism (example: Snider_2013 and Ngoc_2021). These data indicate that the variant may be associated with disease. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. Three clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014 and all classified the variant as likely pathogenic. Based on the evidence outlined above, the variant was classified as likely pathogenic. -
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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not provided Pathogenic:1
ClinVar contains an entry for this variant (Variation ID: 370935). This variant is also known as c.3403-1G>A. Disruption of this splice site has been observed in individual(s) with autosomal recessive neonatal diabetes mellitus and/or hyperinsulinism (PMID: 23275527, 34566892). This variant is not present in population databases (gnomAD no frequency). This sequence change affects an acceptor splice site in intron 27 of the ABCC8 gene. It is expected to disrupt RNA splicing. Variants that disrupt the donor or acceptor splice site typically lead to a loss of protein function (PMID: 16199547), and loss-of-function variants in ABCC8 are known to be pathogenic (PMID: 20685672, 23345197). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. In summary, the currently available evidence indicates that the variant is pathogenic, but additional data are needed to prove that conclusively. Therefore, this variant has been classified as Likely Pathogenic. -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at