rs781763471

Variant names:

• chr6-31967002-A-C
• rs781763471
• NM_006929.5:c.2341-2A>C

Your query was ambiguous. Multiple possible variants found:

• chr6-31967002-A-C
• chr6-31967002-A-G

Variant summary

Our verdict is Uncertain significance. The variant received 4 ACMG points: 4P and 0B. PVS1_Moderate PP5_Moderate

The NM_006929.5(SKIC2):​c.2341-2A>C variant causes a splice acceptor, intron change. The variant allele was found at a frequency of 0.0000103 in 1,460,732 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: not found (cov: 32)
  • Exomes 𝑓: 0.000010 (0 hom.)
• Consequence: SKIC2 NM_006929.5 splice_acceptor, intron
• Scores: Splicing: ADA: 1.000
• Clinical Significance: Likely pathogenic criteria provided, single submitter P:1
• Conservation: PhyloP100: 5.42
• Publications: 2 publications found

Genes affected

SKIC2 (HGNC:10898): (SKI2 subunit of superkiller complex) DEAD box proteins, characterized by the conserved motif Asp-Glu-Ala-Asp (DEAD), are putative RNA helicases. They are implicated in a number of cellular processes involving alteration of RNA secondary structure such as translation initiation, nuclear and mitochondrial splicing, and ribosome and spliceosome assembly. Based on their distribution patterns, some members of this family are believed to be involved in embryogenesis, spermatogenesis, and cellular growth and division. This gene encodes a DEAD box protein, which is a human homologue of yeast SKI2 and may be involved in antiviral activity by blocking translation of poly(A) deficient mRNAs. This gene is located in the class III region of the major histocompatibility complex. [provided by RefSeq, Jul 2008]

SKIC2 Gene-Disease associations (from GenCC):

• trichohepatoenteric syndrome 2

  Inheritance: AR Classification: DEFINITIVE, STRONG, MODERATE Submitted by: Ambry Genetics, Labcorp Genetics (formerly Invitae), PanelApp Australia, G2P
• trichohepatoenteric syndrome

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Uncertain_significance. The variant received 4 ACMG points.

• PVS1: Splicing +-2 bp (donor or acceptor) variant, product NOT destroyed by NMD, known LOF gene, truncates exone, which is 0.036888532 fraction of the gene. Cryptic splice site detected, with MaxEntScore 4.7, offset of 12, new splice context is: cacccacggcccatgaacAGgcc. Cryptic site results in inframe change. If cryptic site found is not functional and variant results in exon loss, it results in inframe change.
• PP5: Variant 6-31967002-A-C is Pathogenic according to our data. Variant chr6-31967002-A-C is described in ClinVar as Likely_pathogenic. ClinVar VariationId is 2803130.Status of the report is criteria_provided_single_submitter, 1 stars.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_006929.5. 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
	SKIC2	NM_006929.5	MANE Select	c.2341-2A>C		splice_acceptor intron	N/A	NP_008860.4

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	SKIC2	ENST00000375394.7	TSL:1 MANE Select	c.2341-2A>C		splice_acceptor intron	N/A	ENSP00000364543.2
	SKIC2	ENST00000465703.5	TSL:1	n.2840-2A>C		splice_acceptor intron	N/A
	SKIC2	ENST00000697840.1		c.2377-2A>C		splice_acceptor intron	N/A	ENSP00000513458.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.0000103 AC: 15 AN: 1460732 Hom.: 0 Cov.: 32 AF XY: 0.0000110 AC XY: 8 AN XY: 726682

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

American (AMR) AF: 0.00 AC: 0 AN: 44724

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26136

East Asian (EAS) AF: 0.000378 AC: 15 AN: 39700

South Asian (SAS) AF: 0.00 AC: 0 AN: 86256

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 52344

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5708

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1112010

Other (OTH) AF: 0.00 AC: 0 AN: 60378

GnomAD4 genome Cov.: 32

ClinVar

Significance: Likely pathogenic

Submissions summary: Pathogenic:1

Revision: criteria provided, single submitter

Submissions by phenotype

not provided Pathogenic:1

Jun 18, 2023

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

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. Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. Disruption of this splice site has been observed in individual(s) with trichohepatoenteric syndrome (PMID: 29527791). This variant is not present in population databases (gnomAD no frequency). This sequence change affects an acceptor splice site in intron 19 of the SKIV2L 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 SKIV2L are known to be pathogenic (PMID: 22444670).

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.63	D
BayesDel_noAF	Uncertain	0.10
CADD	Pathogenic	28
DANN	Uncertain	0.99
Eigen	Pathogenic	1.0
Eigen_PC	Pathogenic	0.84
FATHMM_MKL	Pathogenic	1.0	D
PhyloP100		5.4
GERP RS		5.5
Mutation Taster		=0/100	disease causing

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		0.69		Position offset: 14
DS_AL_spliceai		1.0		Position offset: 2

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

Other links and lift over

dbSNP: rs781763471; hg19: chr6-31934779;