rs753581033

Positions:

• chr4-5563114-TG-T

Variant summary

Our verdict is Pathogenic. Variant got 14 ACMG points: 14P and 0B. PVS1_Strong PM2 PP5_Very_Strong

The ENST00000344408.10(EVC2):​c.3660del​(p.Ser1220ArgfsTer3) variant causes a frameshift, splice region change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000684 in 1,460,930 control chromosomes in the GnomAD database, with no homozygous occurrence. 1/1 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Pathogenic (★★).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000068 (0 hom.)
• Consequence: EVC2 ENST00000344408.10 frameshift, splice_region
• Clinical Significance: Pathogenic criteria provided, multiple submitters, no conflicts P:6
• Conservation: PhyloP100: 0.614

Genes affected

EVC2 (HGNC:19747): (EvC ciliary complex subunit 2) This gene encodes a protein that functions in bone formation and skeletal development. Mutations in this gene, as well as in a neighboring gene that lies in a head-to-head configuration, cause Ellis-van Creveld syndrome, an autosomal recessive skeletal dysplasia that is also known as chondroectodermal dysplasia. Mutations in this gene also cause acrofacial dysostosis Weyers type, also referred to as Curry-Hall syndrome, a disease that combines limb and facial abnormalities. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Oct 2009]

ACMG classification

Verdict is Pathogenic. Variant got 14 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. There are 8 pathogenic variants in the truncated region.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 4-5563114-TG-T is Pathogenic according to our data. Variant chr4-5563114-TG-T is described in ClinVar as [Pathogenic]. Clinvar id is 553833.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr4-5563114-TG-T is described in Lovd as [Pathogenic]. Variant chr4-5563114-TG-T is described in Lovd as [Pathogenic]. Variant chr4-5563114-TG-T is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
EVC2	NM_147127.5	c.3660del	p.Ser1220ArgfsTer3	frameshift_variant, splice_region_variant	22/22	ENST00000344408.10	NP_667338.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
EVC2	ENST00000344408.10	c.3660del	p.Ser1220ArgfsTer3	frameshift_variant, splice_region_variant	22/22	1	NM_147127.5	ENSP00000342144	P2
EVC2	ENST00000310917.6	c.3420del	p.Ser1140ArgfsTer3	frameshift_variant, splice_region_variant	22/22	1		ENSP00000311683	A2
EVC2	ENST00000475313.5	c.3419+2143del		intron_variant, NMD_transcript_variant		1		ENSP00000431981
EVC2	ENST00000509670.1	c.*2053del		splice_region_variant, 3_prime_UTR_variant, NMD_transcript_variant	23/23	1		ENSP00000423876

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD3 exomes AF: 0.0000200 AC: 5 AN: 250124 Hom.: 0 AF XY: 0.00000738 AC XY: 1 AN XY: 135468

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.0000868

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.0000176

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000684 AC: 10 AN: 1460930 Hom.: 0 Cov.: 31 AF XY: 0.00000550 AC XY: 4 AN XY: 726780

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.000134

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: 0.00000360

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

Bravo AF: 0.00000756

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:6

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Ellis-van Creveld syndrome Pathogenic:3

Pathogenic, no assertion criteria provided	literature only	OMIM	Mar 01, 2003	- -
Pathogenic, criteria provided, single submitter	clinical testing	Counsyl	Sep 13, 2017	- -
Pathogenic, criteria provided, single submitter	clinical testing	Women's Health and Genetics/Laboratory Corporation of America, LabCorp	Sep 08, 2022	Variant summary: EVC2 c.3660delC (p.Ser1220ArgfsX3) results in a premature termination codon, predicted to cause a truncation of the encoded protein or absence of the protein due to nonsense mediated decay, which are commonly known mechanisms for disease. Truncations downstream of this position have been classified as pathogenic in ClinVar database. The variant allele was found at a frequency of 2e-05 in 250124 control chromosomes (gnomAD). c.3660delC has been reported in the literature in multiple individuals affected with Ellis-Van Creveld Syndrome, including homozygotes (Ruiz-Perez_2003, Valencia_2009). These data indicate that the variant is very likely to be associated with disease. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. Three ClinVar submitters (evaluation after 2014) cite the variant as pathogenic. Based on the evidence outlined above, the variant was classified as pathogenic. -

Ellis-van Creveld syndrome;C0457013:Curry-Hall syndrome Pathogenic:2

Pathogenic, criteria provided, single submitter	clinical testing	Fulgent Genetics, Fulgent Genetics	Mar 20, 2022	- -
Pathogenic, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	Oct 27, 2023	This sequence change creates a premature translational stop signal (p.Ser1220Argfs*3) in the EVC2 gene. While this is not anticipated to result in nonsense mediated decay, it is expected to disrupt the last 89 amino acid(s) of the EVC2 protein. This variant is present in population databases (rs753581033, gnomAD 0.009%). This premature translational stop signal has been observed in individuals with autosomal recessive Ellis-van Creveld syndrome (PMID: 12571802, 17024374, 19810119, 23220543). This variant is also known as c.3660delC. ClinVar contains an entry for this variant (Variation ID: 553833). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. This variant disrupts a region of the EVC2 protein in which other variant(s) (p.Leu1265Tyrfs*2) have been determined to be pathogenic (PMID: 16404586). This suggests that this is a clinically significant region of the protein, and that variants that disrupt it are likely to be disease-causing. For these reasons, this variant has been classified as Pathogenic. -

not provided Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

GeneDx

Mar 01, 2021

Frameshift variant in the C-terminus predicted to result in protein truncation, as the last 89 amino acids are lost and replaced with 2 incorrect amino acids (Stenson et al., 2014); Not observed at a significant frequency in large population cohorts (Lek et al., 2016); This variant is associated with the following publications: (PMID: 31589614, 19810119, 17024374, 12571802, 19876929, 23220543) -

Computational scores

Source: dbNSFP v4.3

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.93		Details are displayed if max score is > 0.2
DS_AG_spliceai		0.93		Position offset: 0
DS_AL_spliceai		0.75		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: rs753581033; hg19: chr4-5564841;