11-17474955-C-T

Variant names:

• chr11-17474955-C-T
• rs72559734
• NM_000352.6:c.221G>A

Variant summary

Our verdict is Pathogenic. The variant received 14 ACMG points: 14P and 0B. PM1 PM5 PP3_Moderate PP5_Very_Strong

The NM_000352.6(ABCC8):​c.221G>A​(p.Arg74Gln) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000496 in 1,614,066 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 Pathogenic (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R74W) has been classified as Likely pathogenic.

• Frequency:
  • Genomes: 𝑓 0.0000066 (0 hom., cov: 32)
  • Exomes 𝑓: 0.0000048 (0 hom.)
• Consequence: ABCC8 NM_000352.6 missense
• Clinical Significance: Pathogenic criteria provided, multiple submitters, no conflicts P:10
• Conservation: PhyloP100: 7.89
• Publications: 13 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 14 ACMG points.

• PM1: In a hotspot region, there are 4 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 4 uncertain in NM_000352.6
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr11-17474956-G-A is described in ClinVar as Pathogenic/Likely_pathogenic. ClinVar VariationId is 371380.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.9
• PP5: Variant 11-17474955-C-T is Pathogenic according to our data. Variant chr11-17474955-C-T is described in ClinVar as Pathogenic. ClinVar VariationId is 495834.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.221G>A	p.Arg74Gln	missense_variant	Exon 2 of 39	ENST00000389817.8	NP_000343.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
ABCC8	ENST00000389817.8	c.221G>A	p.Arg74Gln	missense_variant	Exon 2 of 39	1	NM_000352.6	ENSP00000374467.4

Frequencies

GnomAD3 genomes AF: 0.00000657 AC: 1 AN: 152200 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.0000241

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.00

Gnomad OTH AF: 0.00

GnomAD2 exomes AF: 0.00000796 AC: 2 AN: 251390 AF XY: 0.00000736

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00000880

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000479 AC: 7 AN: 1461866 Hom.: 0 Cov.: 30 AF XY: 0.00000550 AC XY: 4 AN XY: 727240

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

American (AMR) AF: 0.0000224 AC: 1 AN: 44702

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

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

South Asian (SAS) AF: 0.0000348 AC: 3 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: 0.00000270 AC: 3 AN: 1112006

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

GnomAD4 genome AF: 0.00000657 AC: 1 AN: 152200 Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0 AN XY: 74356

African (AFR) AF: 0.0000241 AC: 1 AN: 41454

American (AMR) AF: 0.00 AC: 0 AN: 15276

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3470

East Asian (EAS) AF: 0.00 AC: 0 AN: 5194

South Asian (SAS) AF: 0.00 AC: 0 AN: 4828

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10616

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 316

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 68040

Other (OTH) AF: 0.00 AC: 0 AN: 2094

Alfa AF: 0.0000226 Hom.: 0

Bravo AF: 0.0000227

ExAC AF: 0.00000824 AC: 1

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:10

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not provided Pathogenic:4

Feb 14, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces arginine, which is basic and polar, with glutamine, which is neutral and polar, at codon 74 of the ABCC8 protein (p.Arg74Gln). This variant is present in population databases (rs72559734, gnomAD 0.003%). This missense change has been observed in individual(s) with autosomal recessive familial hyperinsulinism (PMID: 21992908, 23345197). 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: 495834). 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 80%. This variant disrupts the p.Arg74 amino acid residue in ABCC8. Other variant(s) that disrupt this residue have been determined to be pathogenic (PMID: 14692646, 16429405, 24645945, 25518065). This suggests that this residue is clinically significant, and that variants that disrupt this residue are likely to be disease-causing. For these reasons, this variant has been classified as Pathogenic. -

May 21, 2018

Genetic Services Laboratory, University of Chicago

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Mar 17, 2022

GeneDx

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; This variant is associated with the following publications: (PMID: 33046911, 30352420, 9618169, 27810688, 23275527, 20685672, 21992908, 23345197) -

Jul 15, 2022

Athena Diagnostics

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The frequency of this variant in the general population is consistent with pathogenicity (http://gnomad.broadinstitute.org). This variant has been identified in multiple unrelated individuals with congenital hyperinsulinism. This variant is statistically more frequent in affected individuals than in the general population and/or healthy controls. Computational tools predict that this variant is damaging. -

Hyperinsulinemic hypoglycemia, familial, 1 Pathogenic:2

Aug 16, 2023

Broad Center for Mendelian Genomics, Broad Institute of MIT and Harvard

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: curation

The p.Arg74Gln variant in ABCC8 has been reported in >10 individuals with hyperinsulinemic hypoglycemia (PMID: 9618169, 10338089, 10828824, 20685672, 23275527, 23345197, 28701683, 30352420, 36239000), and has been identified in 0.003% (1/30616) of South Asian chromosomes by the Genome Aggregation Database (gnomAD, http://gnomad.broadinstitute.org; dbSNP rs72559734). 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: 495834) and has been interpreted as pathogenic by multiple sources. Of the many affected individuals, at least 5 were compound heterozygotes that carried a reported pathogenic variant in trans, and at least 1 was a homozygote, which increases the likelihood that the p.Arg74Gln variant is pathogenic (Variation ID: 9088, 188915, 210074, 188931; PMID: 23275527, 23345197, 30352420, 36239000). 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, PM2_supporting, PP3 (Richards 2015). -

Feb 26, 2019

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. -

Familial hyperinsulinism Pathogenic:1

Jul 27, 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.221G>A (p.Arg74Gln) 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 was found at a low frequency in the control population (1/121894 control chromosomes). The variant was reported in the literature in multiple patients with congenital hyperinsulinemia (CHI) both in the homozgous and compound heterozygous states. Taken together, this variant is classified as pathogenic. -

Type 2 diabetes mellitus Pathogenic:1

Jun 14, 2023

Baylor Genetics

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Type 2 diabetes mellitus;C0271714:Leucine-induced hypoglycemia;C1833104:Permanent neonatal diabetes mellitus;C1835887:Diabetes mellitus, transient neonatal, 2;C2931832:Hyperinsulinemic hypoglycemia, familial, 1 Pathogenic:1

Oct 31, 2018

Fulgent Genetics, Fulgent 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

Apr 29, 2024

Fulgent Genetics, Fulgent Genetics

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.94
BayesDel_addAF	Pathogenic	0.47	D
BayesDel_noAF	Pathogenic	0.53
CADD	Pathogenic	31
DANN	Pathogenic	1.0
DEOGEN2	Uncertain	0.58	.;.;D;.;.;.;.;.
Eigen	Pathogenic	0.76
Eigen_PC	Pathogenic	0.70
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Pathogenic	1.0	D;.;D;D;D;D;D;D
M_CAP	Pathogenic	0.68	D
MetaRNN	Pathogenic	0.90	D;D;D;D;D;D;D;D
MetaSVM	Pathogenic	1.0	D
MutationAssessor	Uncertain	2.4	.;M;M;M;.;.;.;.
PhyloP100		7.9
PrimateAI	Pathogenic	0.82	D
PROVEAN	Uncertain	-2.8	.;.;D;D;.;.;.;.
REVEL	Pathogenic	0.90
Sift	Uncertain	0.0030	.;.;D;D;.;.;.;.
Sift4G	Uncertain	0.0030	.;.;D;D;.;.;.;.
Polyphen		1.0	.;.;D;.;.;.;.;.
Vest4		0.81, 0.82
MVP		0.97
MPC		0.99
ClinPred		0.99	D
GERP RS		5.2
Varity_R		0.80
gMVP		0.85
Mutation Taster		=2/98	disease causing (ClinVar)

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.0		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: rs72559734; hg19: chr11-17496502; COSMIC: COSV100217473;