chr14-91234075-C-CG

Position:

• chr14-91234075-C-CG

Variant summary

Our verdict is Likely pathogenic. Variant got 6 ACMG points: 6P and 0B. PVS1_Strong PM2

The NM_001177676.2(GPR68):​c.975_976insC​(p.Glu326ArgfsTer11) variant causes a frameshift change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency: Genomes: not found (cov: 32)
• Consequence: GPR68 NM_001177676.2 frameshift
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: -1.31

Genes affected

GPR68 (HGNC:4519): (G protein-coupled receptor 68) The protein encoded by this gene is a G protein-coupled receptor for sphingosylphosphorylcholine. The encoded protein is a proton-sensing receptor, inactive at pH 7.8 but active at pH 6.8. Mutations in this gene are a cause of amelogenesis imperfecta. [provided by RefSeq, Feb 2017]

ACMG classification

Verdict is Likely_pathogenic. Variant got 6 ACMG points.

• PVS1: Loss of function variant, product does not undergo nonsense mediated mRNA decay. Variant is located in the 3'-most exon, not predicted to undergo nonsense mediated mRNA decay. Fraction of 0.112 CDS is truncated, and there are 0 pathogenic variants in the truncated region.
• PM2: Very rare variant in population databases, with high coverage

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
GPR68	NM_001177676.2	c.975_976insC	p.Glu326ArgfsTer11	frameshift_variant	2/2	ENST00000650645.1	NP_001171147.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
GPR68	ENST00000650645.1	c.975_976insC	p.Glu326ArgfsTer11	frameshift_variant	2/2		NM_001177676.2	ENSP00000498702	P1
GPR68	ENST00000529102.1	c.975_976insC	p.Glu326ArgfsTer11	frameshift_variant	2/2	1		ENSP00000432740
GPR68	ENST00000531499.2	c.975_976insC	p.Glu326ArgfsTer11	frameshift_variant	2/2	1		ENSP00000434045	P1
GPR68	ENST00000535815.5	c.975_976insC	p.Glu326ArgfsTer11	frameshift_variant	2/2	1		ENSP00000440797	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 33

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Amelogenesis imperfecta, hypomaturation type, IIa6 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Victorian Clinical Genetics Services, Murdoch Childrens Research Institute

Mar 31, 2022

Based on the classification scheme VCGS_Germline_v1.3.4, this variant is classified as VUS-3B. Following criteria are met: 0102 - Loss of function is a known mechanism of disease in this gene and is associated with hypomaturation type amelogenesis imperfecta IIA6 (MIM#617217). (I) 0106 - This gene is associated with autosomal recessive disease. (I) 0205 - Variant is predicted to result in a truncated protein (premature termination codon is NOT located at least 54 nucleotides upstream of the final exon-exon junction) with less than 1/3 of the protein sequence affected. (SP) 0251 - This variant is heterozygous. (I) 0301 - Variant is absent from gnomAD (both v2 and v3). (SP) 0604 - Variant is not located in an established domain, motif, hotspot or informative constraint region. (I) 0705 - No comparable premature termination variants have previous evidence for pathogenicity. (I) 0807 - This variant has no previous evidence of pathogenicity. (I) 0905 - No published segregation evidence has been identified for this variant. (I) 1007 - No published functional evidence has been identified for this variant. (I) 1205 - This variant has been shown to be maternally inherited (by trio analysis). (I) Legend: (SP) - Supporting pathogenic, (I) - Information, (SB) - Supporting benign -

Computational scores

Source: dbNSFP v4.3

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

No publications associated with this variant yet.

Other links and lift over

hg19: chr14-91700419;