rs919281813

Positions:

• chr11-17463481-T-C

Variant summary

Our verdict is Uncertain significance. Variant got 5 ACMG points: 5P and 0B. PM2 PP3_Moderate PP5

The NM_000352.6(ABCC8):​c.536A>G​(p.Tyr179Cys) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000138 in 1,453,106 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).

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: ABCC8 NM_000352.6 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:1 U:1
• Conservation: PhyloP100: 8.02

Genes affected

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]

ABCC8 (HGNC:):

ACMG classification

Verdict is Uncertain_significance. Variant got 5 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.887
• PP5: Variant 11-17463481-T-C is Pathogenic according to our data. Variant chr11-17463481-T-C is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 552617.We mark this variant Likely_pathogenic, oryginal submissions are: {Uncertain_significance=1, Pathogenic=1}.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
ABCC8	NM_000352.6	c.536A>G	p.Tyr179Cys	missense_variant	4/39	ENST00000389817.8	NP_000343.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
ABCC8	ENST00000389817.8	c.536A>G	p.Tyr179Cys	missense_variant	4/39	1	NM_000352.6	ENSP00000374467.4

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 0.00000138 AC: 2 AN: 1453106 Hom.: 0 Cov.: 32 AF XY: 0.00000277 AC XY: 2 AN XY: 721518

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 9.02e-7

Gnomad4 OTH exome AF: 0.0000166

GnomAD4 genome Cov.: 33

Bravo AF: 0.00000378

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:1 Uncertain:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

not provided Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

May 02, 2022

This sequence change replaces tyrosine, which is neutral and polar, with cysteine, which is neutral and slightly polar, at codon 179 of the ABCC8 protein (p.Tyr179Cys). This variant is not present in population databases (gnomAD no frequency). This missense change has been observed in individual(s) with autosomal recessive diffuse or paternally inherited focal hyperinsulinism (PMID: 18796520, 20685672, 30352420). In at least one individual the data is consistent with being in trans (on the opposite chromosome) from a pathogenic variant. ClinVar contains an entry for this variant (Variation ID: 552617). 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. For these reasons, this variant has been classified as Pathogenic. -

Hyperinsulinemic hypoglycemia, familial, 1 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Counsyl

Jun 27, 2017

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.61
BayesDel_addAF	Pathogenic	0.50	D
BayesDel_noAF	Pathogenic	0.48
CADD	Pathogenic	28
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.85	.;.;D;.;.;.;.;.
Eigen	Pathogenic	0.75
Eigen_PC	Pathogenic	0.72
FATHMM_MKL	Uncertain	0.89	D
LIST_S2	Uncertain	0.97	D;.;D;D;D;D;D;D
M_CAP	Pathogenic	0.58	D
MetaRNN	Pathogenic	0.89	D;D;D;D;D;D;D;D
MetaSVM	Pathogenic	1.0	D
MutationAssessor	Uncertain	2.4	.;M;M;M;.;.;.;.
PrimateAI	Pathogenic	0.82	D
PROVEAN	Pathogenic	-4.7	.;.;D;D;.;.;.;.
REVEL	Pathogenic	0.93
Sift	Uncertain	0.016	.;.;D;D;.;.;.;.
Sift4G	Uncertain	0.0030	.;.;D;D;.;.;.;.
Polyphen		0.99	.;.;D;.;.;.;.;.
Vest4		0.95, 0.96
MutPred		0.45		Loss of sheet (P = 0.1907);Loss of sheet (P = 0.1907);Loss of sheet (P = 0.1907);Loss of sheet (P = 0.1907);Loss of sheet (P = 0.1907);Loss of sheet (P = 0.1907);Loss of sheet (P = 0.1907);Loss of sheet (P = 0.1907);
MVP		0.97
MPC		1.0
ClinPred		1.0	D
GERP RS		5.0
Varity_R		0.77
gMVP		0.89

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.020		Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

LitVar

Other links and lift over

dbSNP: rs919281813; hg19: chr11-17485028;