11-17394333-C-T

Variant names:

• chr11-17394333-C-T
• rs746480424
• NM_000352.6:c.4478G>A

Variant summary

Our verdict is Pathogenic. The variant received 16 ACMG points: 16P and 0B. PM2 PM5 PP3_Strong PP5_Very_Strong

The NM_000352.6(ABCC8):​c.4478G>A​(p.Arg1493Gln) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000031 in 1,613,934 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 Likely pathogenic (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R1493W) has been classified as Pathogenic.

• Frequency:
  • Genomes: 𝑓 0.0000066 (0 hom., cov: 33)
  • Exomes 𝑓: 0.0000027 (0 hom.)
• Consequence: ABCC8 NM_000352.6 missense
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:6
• Conservation: PhyloP100: 7.87
• Publications: 6 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 16 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr11-17394334-G-A is described in ClinVar as Pathogenic. ClinVar VariationId is 9096.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.991
• PP5: Variant 11-17394333-C-T is Pathogenic according to our data. Variant chr11-17394333-C-T is described in ClinVar as Pathogenic/Likely_pathogenic. ClinVar VariationId is 370910.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.4478G>A	p.Arg1493Gln	missense_variant	Exon 37 of 39	ENST00000389817.8	NP_000343.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
ABCC8	ENST00000389817.8	c.4478G>A	p.Arg1493Gln	missense_variant	Exon 37 of 39	1	NM_000352.6	ENSP00000374467.4

Frequencies

GnomAD3 genomes AF: 0.00000657 AC: 1 AN: 152214 Hom.: 0 Cov.: 33

Gnomad AFR AF: 0.00

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: 0.0000147

Gnomad OTH AF: 0.00

GnomAD2 exomes AF: 0.00 AC: 0 AN: 251366 AF XY: 0.00

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: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000274 AC: 4 AN: 1461720 Hom.: 0 Cov.: 32 AF XY: 0.00000413 AC XY: 3 AN XY: 727178

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

American (AMR) AF: 0.00 AC: 0 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: 0.0000116 AC: 1 AN: 86258

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53256

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: 60392

GnomAD4 genome AF: 0.00000657 AC: 1 AN: 152214 Hom.: 0 Cov.: 33 AF XY: 0.0000134 AC XY: 1 AN XY: 74352

African (AFR) AF: 0.00 AC: 0 AN: 41454

American (AMR) AF: 0.00 AC: 0 AN: 15278

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: 4832

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10622

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

European-Non Finnish (NFE) AF: 0.0000147 AC: 1 AN: 68044

Other (OTH) AF: 0.00 AC: 0 AN: 2092

EpiCase AF: 0.0000545

EpiControl AF: 0.00

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:6

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Hyperinsulinemic hypoglycemia, familial, 1 Pathogenic:3

Aug 16, 2023

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

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: curation

The p.Arg1493Gln variant in ABCC8 has been reported in 8 individuals with hyperinsulinemic hypoglycemia (PMID: 20685672, 12199344, 25639667, 21968111, 34304300, 25008049, 23275527, 10426386), and has been identified in 0.0008% (1/129096) of European (Non-Finnish) chromosomes by the Genome Aggregation Database (gnomAD, http://gnomad.broadinstitute.org; dbSNP rs746480424). 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#: 370910) and has been interpreted as pathogenic by Invitae and likely pathogenic by Counsyl and GeneDx. Of the 8 affected individuals, at least 2 were compound heterozygotes that carried a reported pathogenic variant in trans, which increases the likelihood that the p.Arg1493Gln variant is pathogenic (PMID: 10426386, 25008049). Computational prediction tools and conservation analyses suggest that this variant may impact the protein, though this information is not predictive enough to determine pathogenicity. One additional pathogenic variant, resulting in a different amino acid change at the same position, p.Arg1493Trp has been reported in association with disease in ClinVar and the literature, supporting that a change at this position may not be tolerated (Variation ID: 9096, PMID: 30186238, 33688939, 10202168, 10426386, 19475716, 9769320, 15579781). In summary, although additional studies are required to fully establish its clinical significance, this variant is likely pathogenic for autosomal recessive hyperinsulinemic hypoglycemia. ACMG/AMP Criteria applied: PM3_strong, PM5, PP3, PP2_supporting (Richards 2015). -

May 17, 2016

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. -

Jul 17, 2023

Victorian Clinical Genetics Services, Murdoch Childrens Research Institute

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Based on the classification scheme VCGS_Germline_v1.3.4, this variant is classified as Pathogenic. Following criteria are met: 0103 - Loss of function and gain of function are known mechanisms of disease in this gene and are associated with congenital hyperinsulism (CHI) and neonatal diabetes mellitus (NDM), respectively (PMIDs: 32376986, 32027066). (I) 0108 - This gene is known to be associated with both recessive and dominant disease. The ABCC8 gene has been associated with both autosomal recessive and dominant NDM and CHI (PMID: 32027066). Focal CHI is caused by a somatic second hit with the loss of the maternal chromosome 11p15.5 region by uniparental disomy that makes the paternally inherited variant mosaic homozygous (PMID: 32027066). (I) 0112 - The condition associated with this gene has incomplete penetrance. Variable penetrance has been reported for hyperinsulinemic hypoglycaemia, familial, 1 (MIM#256450) (PMID: 20301549). (I) 0200 - Variant is predicted to result in a missense amino acid change from arginine to glutamine. (I) 0251 - This variant is heterozygous. (I) 0304 - Variant is present in gnomAD (v2) <0.01 (1 heterozygote, 0 homozygotes). (SP) 0309 - Multiple alternative amino acid changes at the same position has been observed in gnomAD (v2) (highest allele count: 4 heterozygotes, 0 homozygotes). (I) 0501 - Missense variant consistently predicted to be damaging by multiple in silico tools or highly conserved with a major amino acid change. (SP) 0600 - Variant is located in the annotated ABC transporter domain (DECIPHER). (I) 0702 - Other missense variants comparable to the one identified in this case have strong previous evidence for pathogenicity. p.(Arg1493Pro), p.(Arg1493Trp) and p.(Arg1493Leu) have been classified as likely pathogenic or pathogenic by clinical laboratories in ClinVar. p.(Arg1493Trp) has also been observed in an individual with focal CHI in the literature (PMID: 20685672). (SP) 0801 - This variant has strong previous evidence of pathogenicity in unrelated individuals. This variant has been classified as pathogenic and likely pathogenic by clinical laboratories in ClinVar, and has been observed as paternally inherited in several individuals with CHI in the literature (PMIDs: 10426386, 33502730, 20685672). This includes one individual with focal CHI where the variant was homozygous in focal lesion tissue due to uniparental disomy and the somatic loss of maternal 11p15 (PMID: 10426386). (SP) 1208 - Inheritance information for this variant is not currently available in this individual. (I) Legend: (SP) - Supporting pathogenic, (I) - Information, (SB) - Supporting benign -

not provided Pathogenic:2

Dec 23, 2021

GeneDx

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Identified in multiple other unrelated patients with hyperinsulinism in the published literature, often inherited on the paternal allele; somatic 11p maternal allele studies were not performed (Sang et al., 2014; Gong et al., 2015); Not observed at a significant frequency in large population cohorts (gnomAD); In silico analysis, which includes protein predictors and evolutionary conservation, supports a deleterious effect; Occasionally reported as R1494Q using alternate nomenclature; This variant is associated with the following publications: (PMID: 14692646, 23275527, 21968111, 12199344, 20799350, 23226049, 20685672, 25639667, 10426386, 25008049) -

Jan 09, 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 1493 of the ABCC8 protein (p.Arg1493Gln). This variant is present in population databases (no rsID available, gnomAD 0.007%). This missense change has been observed in individuals with congenital autosomal recessive hyperinsulinism (PMID: 10426386, 12199344, 21968111, 25008049). This variant is also known as R1494Q. ClinVar contains an entry for this variant (Variation ID: 370910). 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%. This variant disrupts the p.Arg1493 amino acid residue in ABCC8. Other variant(s) that disrupt this residue have been determined to be pathogenic (PMID: 9769320, 15579781, 30186238). 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. -

Type 2 diabetes mellitus Pathogenic:1

Mar 25, 2024

Baylor Genetics

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.98
BayesDel_addAF	Pathogenic	0.54	D
BayesDel_noAF	Pathogenic	0.54
CADD	Pathogenic	33
DANN	Pathogenic	1.0
DEOGEN2	Pathogenic	0.97	.;.;D;.;.;.;.;.
Eigen	Pathogenic	0.92
Eigen_PC	Pathogenic	0.84
FATHMM_MKL	Pathogenic	0.97	D
LIST_S2	Pathogenic	0.98	D;.;D;D;D;D;D;D
M_CAP	Pathogenic	0.94	D
MetaRNN	Pathogenic	0.99	D;D;D;D;D;D;D;D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Pathogenic	3.6	.;.;H;.;.;.;.;.
PhyloP100		7.9
PrimateAI	Pathogenic	0.81	D
PROVEAN	Uncertain	-3.4	.;.;D;D;.;.;.;.
REVEL	Pathogenic	0.98
Sift	Pathogenic	0.0	.;.;D;D;.;.;.;.
Sift4G	Uncertain	0.017	.;.;D;D;.;.;.;.
Polyphen		1.0	.;.;D;.;.;.;.;.
Vest4		0.88
MutPred		0.97		.;.;Loss of MoRF binding (P = 0.0143);.;.;.;Loss of MoRF binding (P = 0.0143);.;
MVP		0.97
MPC		1.9
ClinPred		1.0	D
GERP RS		4.9
Varity_R		0.96
gMVP		0.99
Mutation Taster		=3/97	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: rs746480424; hg19: chr11-17415880;