rs1554924079

Variant names:

• chr11-17427091-A-C
• rs1554924079
• NM_000352.6:c.2180T>G

Variant summary

Our verdict is Likely pathogenic. The variant received 9 ACMG points: 9P and 0B. PM1 PM2 PP3_Strong PP5

The NM_000352.6(ABCC8):​c.2180T>G​(p.Leu727Arg) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,760 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). Synonymous variant affecting the same amino acid position (i.e. L727L) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: ABCC8 NM_000352.6 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:1 U:3
• Conservation: PhyloP100: 9.32
• Publications: 0 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: Genomics England PanelApp, Labcorp Genetics (formerly Invitae), Ambry Genetics, Illumina
• diabetes mellitus, permanent neonatal 3

  Inheritance: AR, SD, AD Classification: DEFINITIVE, STRONG Submitted by: Genomics England PanelApp, Labcorp Genetics (formerly Invitae), 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
• diabetes mellitus, transient neonatal, 2

  Inheritance: AD, Unknown Classification: STRONG Submitted by: Labcorp Genetics (formerly Invitae), 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: Genomics England PanelApp, Orphanet
• permanent neonatal diabetes mellitus

  Inheritance: AR, AD Classification: STRONG, SUPPORTIVE Submitted by: Genomics England PanelApp, Orphanet
• 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: Likely_pathogenic. The variant received 9 ACMG points.

• PM1: In a hotspot region, there are 2 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 1 benign, 7 uncertain in NM_000352.6
• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.976
• PP5: Variant 11-17427091-A-C is Pathogenic according to our data. Variant chr11-17427091-A-C is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 553845.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_000352.6. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	ABCC8	NM_000352.6	MANE Select	c.2180T>G	p.Leu727Arg	missense	Exon 16 of 39	NP_000343.2	Q09428-1
	ABCC8	NM_001351295.2		c.2246T>G	p.Leu749Arg	missense	Exon 16 of 39	NP_001338224.1	A0A2R8Y4V0
	ABCC8	NM_001287174.3		c.2180T>G	p.Leu727Arg	missense	Exon 16 of 39	NP_001274103.1	Q09428-2

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	ABCC8	ENST00000389817.8	TSL:1 MANE Select	c.2180T>G	p.Leu727Arg	missense	Exon 16 of 39	ENSP00000374467.4	Q09428-1
	ABCC8	ENST00000644772.1		c.2246T>G	p.Leu749Arg	missense	Exon 16 of 39	ENSP00000494321.1	A0A2R8Y4V0
	ABCC8	ENST00000302539.9	TSL:5	c.2180T>G	p.Leu727Arg	missense	Exon 16 of 39	ENSP00000303960.4	Q09428-2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461760 Hom.: 0 Cov.: 30 AF XY: 0.00000138 AC XY: 1 AN XY: 727184

⚠️ 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: 33478

American (AMR) AF: 0.00 AC: 0 AN: 44706

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26132

East Asian (EAS) AF: 0.00 AC: 0 AN: 39688

South Asian (SAS) AF: 0.00 AC: 0 AN: 86246

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53414

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5766

European-Non Finnish (NFE) AF: 8.99e-7 AC: 1 AN: 1111942

Other (OTH) AF: 0.00 AC: 0 AN: 60388

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0), which strongly suggests a high chance of mosaicism in these individuals.

GnomAD4 genome Cov.: 32

ClinVar

ClinVar submissions

Significance: Conflicting classifications of pathogenicity

Revision: criteria provided, conflicting classifications

Pathogenic	VUS	Benign	Condition
-	1	-	Hyperinsulinemic hypoglycemia, familial, 1 (1)
-	1	-	Maturity-onset diabetes of the young (1)
1	-	-	not provided (1)
-	1	-	Transitory neonatal diabetes mellitus (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.96
BayesDel_addAF	Pathogenic	0.52	D
BayesDel_noAF	Pathogenic	0.50
CADD	Pathogenic	28
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.96	D
Eigen	Pathogenic	0.91
Eigen_PC	Pathogenic	0.83
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Pathogenic	0.98	D
M_CAP	Pathogenic	0.87	D
MetaRNN	Pathogenic	0.98	D
MetaSVM	Pathogenic	1.0	D
MutationAssessor	Pathogenic	3.3	M
PhyloP100		9.3
PrimateAI	Uncertain	0.70	T
PROVEAN	Pathogenic	-5.0	D
REVEL	Pathogenic	0.99
Sift	Uncertain	0.0010	D
Sift4G	Pathogenic	0.0	D
Polyphen		1.0	D
Vest4		0.99
MutPred		0.83		Gain of methylation at L727 (P = 0.0127)
MVP		0.99
MPC		1.1
ClinPred		1.0	D
GERP RS		5.3
Varity_R		0.99
gMVP		0.91
Mutation Taster		=0/100	disease causing

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: rs1554924079; hg19: chr11-17448638;