rs863225280

Variant names:

• chr11-17461722-C-T
• rs863225280
• NM_000352.6:c.683G>A

Variant summary

Our verdict is Pathogenic. The variant received 12 ACMG points: 12P and 0B. PM1 PM2 PP5_Very_Strong

The NM_000352.6(ABCC8):​c.683G>A​(p.Gly228Asp) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000205 in 1,461,894 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Likely pathogenic (★★).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000021 (0 hom.)
• Consequence: ABCC8 NM_000352.6 missense
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:7 O:2
• Conservation: PhyloP100: 2.40
• Publications: 3 publications found

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 Gene-Disease associations (from GenCC):

• hyperinsulinemic hypoglycemia, familial, 1

  Inheritance: AD, AR, SD Classification: DEFINITIVE, STRONG Submitted by: Ambry Genetics, Illumina, Genomics England PanelApp, Labcorp Genetics (formerly Invitae)
• diabetes mellitus, permanent neonatal 3

  Inheritance: AR, SD, AD Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), Genomics England PanelApp, Ambry Genetics
• familial hyperinsulinism

  Inheritance: AR Classification: DEFINITIVE Submitted by: Myriad Women’s Health
• diabetes mellitus

  Inheritance: SD Classification: DEFINITIVE Submitted by: Ambry Genetics
• monogenic diabetes

  Inheritance: SD Classification: DEFINITIVE Submitted by: ClinGen
• diabetes mellitus, noninsulin-dependent

  Inheritance: AD Classification: STRONG Submitted by: Genomics England PanelApp
• hypoglycemia, leucine-induced

  Inheritance: AD Classification: STRONG Submitted by: Genomics England PanelApp
• transient neonatal diabetes mellitus

  Inheritance: AD Classification: STRONG, SUPPORTIVE Submitted by: Orphanet, Genomics England PanelApp
• permanent neonatal diabetes mellitus

  Inheritance: AR, AD Classification: STRONG, SUPPORTIVE Submitted by: Genomics England PanelApp, Orphanet
• diabetes mellitus, transient neonatal, 2

  Inheritance: Unknown, AD Classification: STRONG Submitted by: Genomics England PanelApp, Labcorp Genetics (formerly Invitae)
• pulmonary arterial hypertension

  Inheritance: AD Classification: MODERATE Submitted by: ClinGen
• autosomal dominant hyperinsulinism due to SUR1 deficiency

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• DEND syndrome

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• diazoxide-resistant focal hyperinsulinism due to SUR1 deficiency

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• maturity-onset diabetes of the young

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• autosomal recessive hyperinsulinism due to SUR1 deficiency

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
• type 2 diabetes mellitus

  Inheritance: AD Classification: LIMITED Submitted by: Labcorp Genetics (formerly Invitae)

ACMG classification

Our verdict: Pathogenic. The variant received 12 ACMG points.

• PM1: In a hotspot region, there are 3 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 7 uncertain in NM_000352.6
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 11-17461722-C-T is Pathogenic according to our data. Variant chr11-17461722-C-T is described in ClinVar as Pathogenic/Likely_pathogenic. ClinVar VariationId is 217846.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
ABCC8	NM_000352.6	c.683G>A	p.Gly228Asp	missense_variant	Exon 5 of 39	ENST00000389817.8	NP_000343.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
ABCC8	ENST00000389817.8	c.683G>A	p.Gly228Asp	missense_variant	Exon 5 of 39	1	NM_000352.6	ENSP00000374467.4

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000205 AC: 3 AN: 1461894 Hom.: 0 Cov.: 31 AF XY: 0.00000138 AC XY: 1 AN XY: 727248

⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.

African (AFR) AF: 0.00 AC: 0 AN: 33480

American (AMR) AF: 0.0000447 AC: 2 AN: 44724

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26136

East Asian (EAS) AF: 0.00 AC: 0 AN: 39700

South Asian (SAS) AF: 0.00 AC: 0 AN: 86258

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53420

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5768

European-Non Finnish (NFE) AF: 8.99e-7 AC: 1 AN: 1112012

Other (OTH) AF: 0.00 AC: 0 AN: 60396

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0.0000000568638), which strongly suggests a high chance of mosaicism in these individuals.

GnomAD4 genome Cov.: 32

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:7 Other:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Hyperinsulinemic hypoglycemia, familial, 1 Pathogenic:2 Other:1

May 27, 2024

Clinical Genomics, Uppaluri K&H Personalized Medicine Clinic

Significance: Uncertain risk allele

Review Status: flagged submission

Collection Method: research

This variant is found to be a potent moderate impact, with a CADD score of 22.1 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. -

Feb 14, 2018

Counsyl

Significance: Likely pathogenic

Review Status: no assertion criteria provided

Collection Method: clinical testing

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. -

May 28, 2019

Mendelics

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

not provided Pathogenic:2

Aug 04, 2023

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

For these reasons, this variant has been classified as Pathogenic. Experimental studies have shown that this missense change affects ABCC8 function (PMID: 17466004). 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 not expected to disrupt ABCC8 protein function. ClinVar contains an entry for this variant (Variation ID: 217846). This missense change has been observed in individuals with congenital hyperinsulinism (PMID: 16186397, 17384337, 21968111, 23275527). It has also been observed to segregate with disease in related individuals. This variant is not present in population databases (gnomAD no frequency). This sequence change replaces glycine, which is neutral and non-polar, with aspartic acid, which is acidic and polar, at codon 228 of the ABCC8 protein (p.Gly228Asp). -

Oct 27, 2015

Genomic Diagnostic Laboratory, Division of Genomic Diagnostics, Children's Hospital of Philadelphia

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: clinical testing

- -

Familial hyperinsulinism Pathogenic:1

Apr 28, 2017

Women's Health and Genetics/Laboratory Corporation of America, LabCorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Variant summary: The ABCC8 c.683G>A (p.Gly228Asp) variant involves the alteration of a conserved nucleotide. 3/4 in silico tools predict a damaging outcome for this variant (SNPsandGO not captured due to low reliability index). This variant is absent in 122206 control chromosomes. The variant has been reported in numerous affected individuals in the literature, and has been shown functionally to lead to intracellular retention of the channel complex and loss of function. In addition, one clinical diagnostic laboratory/reputable database classified this variant as pathogenic. Taken together, this variant is classified as pathogenic. -

Type 2 diabetes mellitus Pathogenic:1

Dec 22, 2023

Baylor Genetics

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

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

May 12, 2024

Fulgent Genetics, Fulgent Genetics

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Maturity onset diabetes mellitus in young Other:1

May 27, 2024

Clinical Genomics, Uppaluri K&H Personalized Medicine Clinic

Significance: Uncertain risk allele

Review Status: flagged submission

Collection Method: research

This variant is found to be a potent moderate impact, with a CADD score of 22.1 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: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.96
BayesDel_addAF	Pathogenic	0.29	D
BayesDel_noAF	Pathogenic	0.18
CADD	Uncertain	25
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.45	.;.;T;.;.;.;.;.
Eigen	Uncertain	0.27
Eigen_PC	Uncertain	0.38
FATHMM_MKL	Uncertain	0.90	D
LIST_S2	Uncertain	0.97	D;.;D;D;D;D;D;D
M_CAP	Benign	0.061	D
MetaRNN	Uncertain	0.64	D;D;D;D;D;D;D;D
MetaSVM	Uncertain	0.30	D
MutationAssessor	Benign	1.4	.;L;L;L;.;.;.;.
PhyloP100		2.4
PrimateAI	Pathogenic	0.89	D
PROVEAN	Benign	-1.6	.;.;N;N;.;.;.;.
REVEL	Uncertain	0.61
Sift	Benign	0.036	.;.;D;D;.;.;.;.
Sift4G	Uncertain	0.020	.;.;D;D;.;.;.;.
Polyphen		0.57	.;.;P;.;.;.;.;.
Vest4		0.88, 0.88
MutPred		0.59		Loss of MoRF binding (P = 0.0421);Loss of MoRF binding (P = 0.0421);Loss of MoRF binding (P = 0.0421);Loss of MoRF binding (P = 0.0421);Loss of MoRF binding (P = 0.0421);Loss of MoRF binding (P = 0.0421);Loss of MoRF binding (P = 0.0421);Loss of MoRF binding (P = 0.0421);
MVP		0.93
MPC		0.40
ClinPred		0.89	D
GERP RS		5.4
Varity_R		0.57
gMVP		0.80
Mutation Taster		=5/95	disease causing (ClinVar)

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.010		Details are displayed if max score is > 0.2

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

Other links and lift over

dbSNP: rs863225280; hg19: chr11-17483269;