1-19243708-C-T

Variant summary

Our verdict is Pathogenic. The variant received 16 ACMG points: 16P and 0B. PVS1PP5_Very_Strong

The NM_015047.3(EMC1):​c.287-1G>A variant causes a splice acceptor, intron change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000143 in 1,614,012 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 Likely pathogenic (★★).

Frequency

Genomes: 𝑓 0.000020 ( 0 hom., cov: 32)
Exomes 𝑓: 0.000014 ( 0 hom. )

Consequence

EMC1
NM_015047.3 splice_acceptor, intron

Scores

5
1
1
Splicing: ADA: 1.000
2

Clinical Significance

Likely pathogenic criteria provided, multiple submitters, no conflicts P:3

Conservation

PhyloP100: 7.43

Publications

2 publications found
Variant links:
Genes affected
EMC1 (HGNC:28957): (ER membrane protein complex subunit 1) This gene encodes a single-pass type I transmembrane protein, which is a subunit of the endoplasmic reticulum membrane protein complex (EMC). Multiple alternatively spliced transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Sep 2012]
EMC1 Gene-Disease associations (from GenCC):
  • cerebellar atrophy, visual impairment, and psychomotor retardation;
    Inheritance: AR, AD Classification: STRONG, MODERATE, LIMITED Submitted by: Labcorp Genetics (formerly Invitae), G2P, Ambry Genetics
  • complex neurodevelopmental disorder with motor features
    Inheritance: AD, AR Classification: MODERATE Submitted by: ClinGen
  • global developmental delay-visual anomalies-progressive cerebellar atrophy-truncal hypotonia syndrome
    Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet

Genome browser will be placed here

ACMG classification

Classification was made for transcript

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

PVS1
Splicing +-2 bp (donor or acceptor) variant, LoF is a know mechanism of disease, No cryptic splice site detected. Exon removal results in frameshift change.
PP5
Variant 1-19243708-C-T is Pathogenic according to our data. Variant chr1-19243708-C-T is described in ClinVar as Likely_pathogenic. ClinVar VariationId is 445564.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
EMC1NM_015047.3 linkc.287-1G>A splice_acceptor_variant, intron_variant Intron 3 of 22 ENST00000477853.6 NP_055862.1 Q8N766-1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
EMC1ENST00000477853.6 linkc.287-1G>A splice_acceptor_variant, intron_variant Intron 3 of 22 1 NM_015047.3 ENSP00000420608.1 Q8N766-1

Frequencies

GnomAD3 genomes
AF:
0.0000197
AC:
3
AN:
152210
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.0000482
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:
0.0000147
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.00000398
AC:
1
AN:
251444
AF XY:
0.00000736
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00000879
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000137
AC:
20
AN:
1461802
Hom.:
0
Cov.:
30
AF XY:
0.0000138
AC XY:
10
AN XY:
727208
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33478
American (AMR)
AF:
0.00
AC:
0
AN:
44724
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26134
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39700
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86256
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53420
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
0.0000180
AC:
20
AN:
1111932
Other (OTH)
AF:
0.00
AC:
0
AN:
60390
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.465
Heterozygous variant carriers
0
1
2
4
5
6
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
2
4
6
8
10
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
GnomAD4 genome
AF:
0.0000197
AC:
3
AN:
152210
Hom.:
0
Cov.:
32
AF XY:
0.0000269
AC XY:
2
AN XY:
74362
show subpopulations
African (AFR)
AF:
0.0000482
AC:
2
AN:
41452
American (AMR)
AF:
0.00
AC:
0
AN:
15288
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3466
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5200
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4826
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10624
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000147
AC:
1
AN:
68034
Other (OTH)
AF:
0.00
AC:
0
AN:
2092
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.525
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Genome Het
Variant carriers
0
2
4
6
8
10
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
Alfa
AF:
0.00
Hom.:
0
Bravo
AF:
0.0000189
EpiCase
AF:
0.00
EpiControl
AF:
0.0000593

ClinVar

Significance: Likely pathogenic
Submissions summary: Pathogenic:3
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

not provided Pathogenic:2
May 02, 2017
Center for Pediatric Genomic Medicine, Children's Mercy Hospital and Clinics
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Nov 22, 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 3 of the EMC1 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 EMC1 are known to be pathogenic (PMID: 26572623, 26942288, 29271071). This variant is present in population databases (no rsID available, gnomAD 0.0009%). This variant has not been reported in the literature in individuals affected with EMC1-related conditions. ClinVar contains an entry for this variant (Variation ID: 445564). 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. -

Cerebellar atrophy, visual impairment, and psychomotor retardation; Pathogenic:1
May 02, 2023
Broad Center for Mendelian Genomics, Broad Institute of MIT and Harvard
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:curation

The heterozygous c.287-1G>A variant in EMC1 was identified by our study, in the compound heterozygous state along with a variant of uncertain significance (dbSNP ID: rs1448410617), in one individual with global developmental delay and congenital myopathy. Trio genome analysis revealed that this variant was in trans with a variant of uncertain significance (dbSNP ID: rs1448410617). The c.287-1G>A variant in EMC1 has not been previously reported in individuals with cerebellar atrophy, visual impairment, and psychomotor retardation but has been identified in 0.005% (2/41452) of African/American chromosomes by the Genome Aggregation Database (gnomAD, http://gnomad.broadinstitute.org; dbSNP ID: rs751484278). Although this variant has been seen in the general population in a heterozygous state, its frequency is low enough to be consistent with a recessive carrier frequency. This variant has also been reported in ClinVar (Variation ID: 445564) and has been interpreted as likely pathogenic by Children's Mercy Hospital and Clinics Center for Pediatric Genomic Medicine. This variant is located in the 3' splice region. Computational tools predict a splicing impact, though this information is not predictive enough to determine pathogenicity. A different nucleotide change that also results in a splice acceptor variant at the same site, c.287-1G>T, has been previously reported likely pathogenic in ClinVar (Variation ID: 972296), and the variant being assessed here, c.287-1G>A, is predicted by SpliceAI to have a similar effect on splicing. Loss of function of the EMC1 gene is strongly associated to autosomal recessive cerebellar atrophy, visual impairment, and psychomotor retardation. In summary, although additional studies are required to fully establish its clinical significance, this variant is likely pathogenic for autosomal recessive cerebellar atrophy, visual impairment, and psychomotor retardation. ACMG/AMP Criteria applied: PVS1_Strong, PS1_Supporting, PM2_Supporting (Richards 2015). -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
BayesDel_addAF
Pathogenic
0.63
D
BayesDel_noAF
Pathogenic
0.44
CADD
Pathogenic
34
DANN
Uncertain
1.0
Eigen
Pathogenic
1.2
Eigen_PC
Pathogenic
1.1
FATHMM_MKL
Pathogenic
1.0
D
PhyloP100
7.4
GERP RS
6.1
Mutation Taster
=0/100
disease causing (ClinVar)

Splicing

Name
Calibrated prediction
Score
Prediction
dbscSNV1_ADA
Pathogenic
1.0
dbscSNV1_RF
Pathogenic
0.94
SpliceAI score (max)
1.0
Details are displayed if max score is > 0.2
DS_AG_spliceai
0.22
Position offset: -25
DS_AL_spliceai
1.0
Position offset: -1

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

Publications

Other links and lift over

dbSNP: rs751484278; hg19: chr1-19570202; API