rs1553833239

Variant names:

• chr4-5622993-T-C
• rs1553833239
• NM_147127.5:c.2047-2A>G

Variant summary

Our verdict is Pathogenic. The variant received 16 ACMG points: 16P and 0B. PVS1 PP5_Very_Strong

The NM_147127.5(EVC2):​c.2047-2A>G variant causes a splice acceptor, intron change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000753 in 1,461,510 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Likely pathogenic (★★).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000075 (0 hom.)
• Consequence: EVC2 NM_147127.5 splice_acceptor, intron
• Scores: Splicing: ADA: 1.000
• Clinical Significance: Likely pathogenic criteria provided, multiple submitters, no conflicts P:3
• Conservation: PhyloP100: 2.17
• Publications: 0 publications found

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]

EVC2 Gene-Disease associations (from GenCC):

• acrofacial dysostosis, Weyers type

  Inheritance: AD, AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Ambry Genetics, Labcorp Genetics (formerly Invitae), G2P, Orphanet
• Ellis-van Creveld syndrome

  Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Myriad Women’s Health, Labcorp Genetics (formerly Invitae), Orphanet, Ambry Genetics, Laboratory for Molecular Medicine

ACMG classification

Our verdict: Pathogenic. The variant received 16 ACMG points.

• PVS1: Splicing +-2 bp (donor or acceptor) variant, LoF is a know mechanism of disease, Cryptic splice site detected, with MaxEntScore 3.7, offset of 5, new splice context is: tttctgaaactccggcacAGgga. Cryptic site results in frameshift change. If cryptic site found is not functional and variant results in exon loss, it results in frameshift change.
• PP5: Variant 4-5622993-T-C is Pathogenic according to our data. Variant chr4-5622993-T-C is described in ClinVar as Likely_pathogenic. ClinVar VariationId is 551049.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
EVC2	NM_147127.5	c.2047-2A>G		splice_acceptor_variant, intron_variant	Intron 13 of 21	ENST00000344408.10	NP_667338.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
EVC2	ENST00000344408.10	c.2047-2A>G		splice_acceptor_variant, intron_variant	Intron 13 of 21	1	NM_147127.5	ENSP00000342144.5
EVC2	ENST00000310917.6	c.1807-2A>G		splice_acceptor_variant, intron_variant	Intron 13 of 21	1		ENSP00000311683.2
EVC2	ENST00000475313.5	n.1807-2A>G		splice_acceptor_variant, intron_variant	Intron 13 of 22	1		ENSP00000431981.1
EVC2	ENST00000509670.1	n.*440-2A>G		splice_acceptor_variant, intron_variant	Intron 14 of 22	1		ENSP00000423876.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000753 AC: 11 AN: 1461510 Hom.: 0 Cov.: 34 AF XY: 0.00000413 AC XY: 3 AN XY: 727042

African (AFR) AF: 0.00 AC: 0 AN: 33476

American (AMR) AF: 0.00 AC: 0 AN: 44718

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26126

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

South Asian (SAS) AF: 0.00 AC: 0 AN: 86244

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53234

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5754

European-Non Finnish (NFE) AF: 0.00000899 AC: 10 AN: 1111890

Other (OTH) AF: 0.0000166 AC: 1 AN: 60380

GnomAD4 genome Cov.: 32

ClinVar

Significance: Likely pathogenic

Submissions summary: Pathogenic:3

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

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

Nov 06, 2022

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change affects an acceptor splice site in intron 13 of the EVC2 gene. It is expected to disrupt RNA splicing. Variants that disrupt the donor or acceptor splice site typically lead to a loss of protein function (PMID: 16199547), and loss-of-function variants in EVC2 are known to be pathogenic (PMID: 17024374, 19810119, 19876929). This variant is not present in population databases (gnomAD no frequency). Disruption of this splice site has been observed in individual(s) with Ellis-van Creveld syndrome (PMID: 20184732). ClinVar contains an entry for this variant (Variation ID: 551049). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. 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. -

Oct 31, 2018

Fulgent Genetics, Fulgent Genetics

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Ellis-van Creveld syndrome Pathogenic:1

Mar 23, 2017

Counsyl

Significance: Likely pathogenic

Review Status: no assertion criteria provided

Collection Method: clinical testing

This submission and the accompanying classification are no longer maintained by the submitter. For more information on current observations and classification, please contact variantquestions@myriad.com. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Benign	-0.0031	T
BayesDel_noAF	Benign	-0.24
CADD	Pathogenic	29
DANN	Benign	0.94
Eigen	Pathogenic	0.75
Eigen_PC	Uncertain	0.53
FATHMM_MKL	Uncertain	0.90	D
PhyloP100		2.2
GERP RS		4.6
Mutation Taster		=34/66	disease causing (ClinVar)

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.79
SpliceAI score (max)		0.98		Details are displayed if max score is > 0.2
DS_AG_spliceai		0.64		Position offset: -7
DS_AL_spliceai		0.98		Position offset: -2

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

Other links and lift over

dbSNP: rs1553833239; hg19: chr4-5624720;