rs1554904107

chr11-17394365-G-T

Variant summary

Our verdict is Likely pathogenic. Variant got 8 ACMG points: 8P and 0B. PM1 PM2 PP3_Strong

The NM_000352.6(ABCC8):c.4446C>A(p.Ser1482Arg) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000616 in 1,461,858 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). Another nucleotide change resulting in same amino acid change has been previously reported as Uncertain significancein ClinVar.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.0000062 (0 hom.)
• Consequence: ABCC8 NM_000352.6 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:2 U:3
• Conservation: PhyloP100: 2.51

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]

ACMG classification

Verdict is Likely_pathogenic. Variant got 8 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, 2 uncertain in NM_000352.6
• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.985

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
ABCC8	NM_000352.6	c.4446C>A	p.Ser1482Arg	missense_variant	37/39	ENST00000389817.8

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
ABCC8	ENST00000389817.8	c.4446C>A	p.Ser1482Arg	missense_variant	37/39	1	NM_000352.6	P4

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 0.00000616 AC: 9 AN: 1461858 Hom.: 0 Cov.: 32 AF XY: 0.00000688 AC XY: 5 AN XY: 727232

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: 0.00000719

Gnomad4 OTH exome AF: 0.0000166

GnomAD4 genome Cov.: 33

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:2 Uncertain:3

Revision: criteria provided, conflicting classifications

Submissions by phenotype

not provided Pathogenic:2

Likely pathogenic, no assertion criteria provided	clinical testing	Genetic Services Laboratory, University of Chicago	Sep 02, 2022	DNA sequence analysis of the ABCC8 gene demonstrated a sequence change, c.4446C>A, in exon 37 that results in an amino acid change, p.Ser1482Arg. This sequence change has previously been identified in the compound heterozygous state with a known pathogenic variant in an individual with congenital hyperinsulinism (PMID: 23345197). This sequence change has also not been described in population databases such as ExAC and gnomAD. The p.Ser1482Arg change affects a highly conserved amino acid residue located in a domain of the ABCC8 protein that is known to be functional. The p.Ser1482Arg substitution appears to be damaging using several in-silico pathogenicity prediction tools (SIFT, PolyPhen2, REVEL). This sequence change is the likely cause of this individual's phenotype, however functional studies have not been performed to prove this conclusively. -
Likely pathogenic, criteria provided, single submitter	clinical testing	Invitae	Apr 14, 2023	This variant is also known as c.4449C>A (p.Ser1483Arg). 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. Experimental studies have shown that this missense change affects ABCC8 function (PMID: 12169627). 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. ClinVar contains an entry for this variant (Variation ID: 551204). This missense change has been observed in individual(s) with congenital hyperinsulinism (PMID: 23345197). In at least one individual the data is consistent with being in trans (on the opposite chromosome) from a pathogenic variant. This variant is not present in population databases (gnomAD no frequency). This sequence change replaces serine, which is neutral and polar, with arginine, which is basic and polar, at codon 1482 of the ABCC8 protein (p.Ser1482Arg). -

Maturity onset diabetes mellitus in young Uncertain:1

Uncertain significance, criteria provided, single submitter

research

Clinical Genomics, Uppaluri K&H Personalized Medicine Clinic

-

Mutations in ABCC8 gene are associated with both neonatal diabetes mellitus as well as MODY. Patients with this mutation may have a better response to sulfonylureas. However, no sufficient evidence is found to ascertain the role of this particular variant (rs1554904107) in MODY yet. -

Hyperinsulinemic hypoglycemia, familial, 1 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Counsyl

Mar 21, 2017

- -

Transitory neonatal diabetes mellitus Uncertain:1

Uncertain significance, criteria provided, single submitter

research

Clinical Genomics, Uppaluri K&H Personalized Medicine Clinic

-

Mutations in ABCC8 gene are associated with both neonatal diabetes mellitus as well as MODY. Patients with this mutation may have a better response to sulfonylureas. However, no sufficient evidence is found to ascertain the role of this particular variant (rs1554904107 ) in neonatal diabetes yet. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	1.0
BayesDel_addAF	Pathogenic	0.52	D
BayesDel_noAF	Pathogenic	0.51
Cadd	Pathogenic	26
Dann	Uncertain	1.0
Eigen	Pathogenic	0.76
Eigen_PC	Uncertain	0.61
FATHMM_MKL	Uncertain	0.94	D
LIST_S2	Pathogenic	1.0	D;.;D;D;D;D;D;D
M_CAP	Pathogenic	0.95	D
MetaRNN	Pathogenic	0.98	D;D;D;D;D;D;D;D
MetaSVM	Pathogenic	1.0	D
MutationTaster	Benign	1.0	D;D
PrimateAI	Pathogenic	0.85	D
Polyphen		1.0	.;.;D;.;.;.;.;.
Vest4		0.94
MutPred		0.89		.;.;Gain of MoRF binding (P = 0.0284);.;.;.;Gain of MoRF binding (P = 0.0284);.;
MVP		0.95
MPC		1.9
ClinPred		1.0	D
GERP RS		4.0
Varity_R		0.97
gMVP		1.0

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

Publications

LitVar

Other links and lift over

dbSNP: rs1554904107; hg19: chr11-17415912;