1-108885274-G-A

Variant summary

Our verdict is Pathogenic. Variant got 14 ACMG points: 14P and 0B. PVS1 PM2 PP3_Strong

The NM_013296.5(GPSM2):c.-248-1G>A variant causes a splice acceptor change. The variant allele was found at a frequency of 0.0000205 in 391,102 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: 𝑓 0.000039 (0 hom., cov: 32)
  • Exomes 𝑓: 0.0000084 (0 hom.)
• Consequence: GPSM2 NM_013296.5 splice_acceptor
• Scores: Splicing: ADA: 1.000
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 7.19

Genes affected

GPSM2 (HGNC:29501): (G protein signaling modulator 2) The protein encoded by this gene belongs to a family of proteins that modulate activation of G proteins, which transduce extracellular signals received by cell surface receptors into integrated cellular responses. The N-terminal half of this protein contains 10 copies of leu-gly-asn (LGN) repeat, and the C-terminal half contains 4 GoLoco motifs, which are involved in guanine nucleotide exchange. This protein may play a role in neuroblast division and in the development of normal hearing. Mutations in this gene are associated with autosomal recessive nonsyndromic deafness (DFNB82). Alternative splicing results in multiple transcript variants. [provided by RefSeq, Mar 2016]

AKNAD1 (HGNC:28398): (AKNA domain containing 1) This gene encodes a protein which contains a domain found in an AT-hook-containing transcription factor. Alternative splicing results in multiple transcript variants. [provided by RefSeq, May 2012]

CLCC1 (HGNC:29675): (chloride channel CLIC like 1) Predicted to enable chloride channel activity. Predicted to be involved in chloride transport. Located in endoplasmic reticulum and mitochondria-associated endoplasmic reticulum membrane. Implicated in retinitis pigmentosa 32. [provided by Alliance of Genome Resources, Apr 2022]

ACMG classification

Verdict is Pathogenic. Variant got 14 ACMG points.

• PVS1: Splicing variant, LoF is a know mechanism of disease, Cryptic splice site detected, with MaxEntScore 5, offset of -35, new splice context is: aggttgttctttgaaaatAGgac. Cryptic site results in frameshift change. If cryptic site found is not functional and variant results in exon loss, it results in frameshift change.
• PM2: Very rare variant in population databases, with high coverage
• PP3: Splicing scoreres supports a deletorius effect: Scorers claiming Pathogenic: dbscSNV1_ADA, dbscSNV1_RF, max_spliceai. No scorers claiming Uncertain. No scorers claiming Benign.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
GPSM2	NM_013296.5	c.-248-1G>A		splice_acceptor_variant		ENST00000264126.9

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
GPSM2	ENST00000264126.9	c.-248-1G>A		splice_acceptor_variant		1	NM_013296.5	P1

Frequencies

GnomAD3 genomes AF: 0.0000394 AC: 6 AN: 152184 Hom.: 0 Cov.: 32

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: 0.0000882

Gnomad OTH AF: 0.00

GnomAD4 exome AF: 0.00000837 AC: 2 AN: 238918 Hom.: 0 Cov.: 0 AF XY: 0.0000161 AC XY: 2 AN XY: 124404

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: 0.0000134

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome AF: 0.0000394 AC: 6 AN: 152184 Hom.: 0 Cov.: 32 AF XY: 0.0000404 AC XY: 3 AN XY: 74348

Gnomad4 AFR AF: 0.00

Gnomad4 AMR AF: 0.00

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.0000882

Gnomad4 OTH AF: 0.00

Alfa AF: 0.000162 Hom.: 0

Bravo AF: 0.0000113

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Chudley-McCullough syndrome Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

Aug 22, 2018

This variant occurs in a canonical splice site (acceptor) and is therefore predicted to disrupt or distort the normal gene product. It was observed by ICSL as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018) and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score for this variant, it could not be ruled out of causing disease and therefore its association with disease required further investigation. A literature search was performed for the gene and cDNA change. No publications were found based on this search. Due to the potential impact of splice acceptor variants and the lack of clarifying evidence, this variant is classified as a variant of uncertain significance but suspicious for pathogenicity for this disease. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Pathogenic	0.31
Cadd	Pathogenic	33
Dann	Uncertain	1.0

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.94
SpliceAI score (max)		0.80		Details are displayed if max score is > 0.2
DS_AL_spliceai		0.80		Position offset: 1

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

Publications

LitVar

Other links and lift over

dbSNP: rs1051372133; hg19: chr1-109427896;