NM_022464.5:c.645+2T>C

Variant names:

Variant summary

Our verdict is Pathogenic. The variant received 14 ACMG points: 14P and 0B. PVS1_StrongPM2PP5_Very_Strong

The NM_022464.5(SIL1):c.645+2T>C variant causes a splice donor, intron change. The variant allele was found at a frequency of 0.0000316 in 1,613,898 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 2/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Likely pathogenic (★★).

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 32)

Exomes 𝑓: 0.000034 ( 0 hom. )

Consequence

SIL1
NM_022464.5 splice_donor, intron

Scores

Splicing: ADA: 0.9937

Clinical Significance

Likely pathogenic criteria provided, multiple submitters, no conflicts P:4

Conservation

PhyloP100: 7.16

Publications

0 publications found

Variant links:

Genes affected

SIL1 (HGNC:24624): (SIL1 nucleotide exchange factor) This gene encodes a resident endoplasmic reticulum (ER), N-linked glycoprotein with an N-terminal ER targeting sequence, 2 putative N-glycosylation sites, and a C-terminal ER retention signal. This protein functions as a nucleotide exchange factor for another unfolded protein response protein. Mutations in this gene have been associated with Marinesco-Sjogren syndrome. Alternate transcriptional splice variants have been characterized. [provided by RefSeq, Jul 2008]

SIL1 Gene-Disease associations (from GenCC):

Marinesco-Sjogren syndrome
Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: ClinGen, G2P, Orphanet, Labcorp Genetics (formerly Invitae)

SIL1 links:

ENSG00000249593 (HGNC:):

ENSG00000249593 links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Pathogenic. The variant received 14 ACMG points.

PVS1

Splicing +-2 bp (donor or acceptor) variant, product NOT destroyed by NMD, known LOF gene, truncates exone, which is 0.13852814 fraction of the gene. No cryptic splice site detected. Exon removal is inframe change.

PM2

Very rare variant in population databases, with high coverage;

PP5

Variant 5-139026799-A-G is Pathogenic according to our data. Variant chr5-139026799-A-G is described in ClinVar as Likely_pathogenic. ClinVar VariationId is 2624.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_022464.5. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	SIL1	NM_022464.5	MANE Select	c.645+2T>C		splice_donor intron	N/A	NP_071909.1
	SIL1	NM_001037633.2		c.645+2T>C		splice_donor intron	N/A	NP_001032722.1

Ensembl Transcripts

Gene	Transcript	Tags	HGVSc	Effect	Exon Rank	Protein
SIL1	ENST00000394817.7	TSL:1 MANE Select	c.645+2T>C	splice_donor intron	N/A	ENSP00000378294.2
SIL1	ENST00000505945.1	TSL:1	c.64-5507T>C	intron	N/A	ENSP00000425136.1
SIL1	ENST00000509534.5	TSL:5	c.666+2T>C	splice_donor intron	N/A	ENSP00000426858.1

Frequencies

GnomAD3 genomes

AF:

0.00000657

AC:

AN:

152196

Hom.:

Cov.:

show subpopulations

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:

0.0000147

Gnomad OTH

AF:

0.00

GnomAD2 exomes

AF:

0.0000358

AC:

AN:

251240

AF XY:

0.0000295

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:

0.0000792

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000342

AC:

AN:

1461702

Hom.:

Cov.:

AF XY:

0.0000344

AC XY:

AN XY:

727150

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

33476

American (AMR)

AF:

0.00

AC:

AN:

44724

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26136

East Asian (EAS)

AF:

0.00

AC:

AN:

39700

South Asian (SAS)

AF:

0.00

AC:

AN:

86250

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53366

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5768

European-Non Finnish (NFE)

AF:

0.0000441

AC:

AN:

1111888

Other (OTH)

AF:

0.0000166

AC:

AN:

60394

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.492

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome Het

Variant carriers

<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:

0.00000657

AC:

AN:

152196

Hom.:

Cov.:

AF XY:

0.0000135

AC XY:

AN XY:

74334

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

41456

American (AMR)

AF:

0.00

AC:

AN:

15278

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3470

East Asian (EAS)

AF:

0.00

AC:

AN:

5194

South Asian (SAS)

AF:

0.00

AC:

AN:

4818

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10622

Middle Eastern (MID)

AF:

0.00

AC:

AN:

316

European-Non Finnish (NFE)

AF:

0.0000147

AC:

AN:

68036

Other (OTH)

AF:

0.00

AC:

AN:

2094

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.475

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Alfa

AF:

0.0000386

Hom.:

Bravo

AF:

0.00000378

ExAC

AF:

0.0000576

AC:

EpiCase

AF:

0.00

EpiControl

AF:

0.0000593

ClinVar

Significance: Likely pathogenic

Submissions summary: Pathogenic:4

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Marinesco-Sjögren syndrome

Pathogenic:4

UNC Molecular Genetics Laboratory, University of North Carolina at Chapel Hill

Significance:Likely pathogenic

Review Status:criteria provided, single submitter

Collection Method:research

The SIL1 c.645+2T>C (p.?) variant is located in a splice donor site and has been observed in the compound heterozygous state in a family with Marinesco-Sjogren syndrome (PMID: 16282978).

Jun 21, 2024

Women's Health and Genetics/Laboratory Corporation of America, LabCorp

Significance:Likely pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Variant summary: SIL1 c.645+2T>C is located in a canonical splice-site and is predicted to affect mRNA splicing resulting in a significantly altered protein due to either exon skipping, shortening, or inclusion of intronic material. Several computational tools predict a significant impact on normal splicing: Four predict the variant abolishes a 5' splicing donor site. At least one publication reports experimental evidence that this variant affects mRNA splicing in patient cells, resulting in the in-frame skipping of exon 6 (example, Antonnen_2005). The variant allele was found at a frequency of 3.6e-05 in 251240 control chromosomes. c.645+2T>C has been reported in the literature in the compound heterozygous state in two individuals affected with Marinesco-Sjogren Syndrome (example, Antonnen_2005). These data indicate that the variant may be associated with disease. The following publication has been ascertained in the context of this evaluation (PMID: 16282978). ClinVar contains an entry for this variant (Variation ID: 2624). Based on the evidence outlined above, the variant was classified as likely pathogenic.

Dec 01, 2005

OMIM

Significance:Pathogenic

Review Status:no assertion criteria provided

Collection Method:literature only

Mar 20, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Likely pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This sequence change affects a donor splice site in intron 6 of the SIL1 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 SIL1 are known to be pathogenic (PMID: 16282977, 24176978). This variant is present in population databases (rs548535414, gnomAD 0.008%). Disruption of this splice site has been observed in individual(s) with Marinesco-Sjogren syndrome (PMID: 16282978). In at least one individual the data is consistent with being in trans (on the opposite chromosome) from a pathogenic variant. ClinVar contains an entry for this variant (Variation ID: 2624). Studies have shown that disruption of this splice site is associated with altered splicing resulting in multiple RNA products (PMID: 16282978). 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.

Computational scores

Source: dbNSFP v4.9

Name

Calibrated prediction

Score

Prediction

BayesDel_addAF

Pathogenic

0.48

BayesDel_noAF

Pathogenic

0.33

CADD

Pathogenic

(source)

DANN

Uncertain

0.99

Eigen

Pathogenic

1.1

Eigen_PC

Pathogenic

0.96

FATHMM_MKL

Pathogenic

0.99

PhyloP100

7.2

GERP RS

5.6

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

2.8

Mutation Taster

=0/100

disease causing (ClinVar)

(source)

Splicing

Name

Calibrated prediction

Score

Prediction

dbscSNV1_ADA

Pathogenic

0.99

dbscSNV1_RF

Benign

0.62

SpliceAI score (max)

0.86

Details are displayed if max score is > 0.2

DS_DL_spliceai

0.86

Position offset: 2

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

Publications

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Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Variant Effect in Transcripts

RefSeq Transcripts

Ensembl Transcripts

Frequencies

Age Distribution

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over