1-209790892-A-C

Position:

• chr1-209790892-A-C

Variant summary

Our verdict is Uncertain significance. Variant got 3 ACMG points: 3P and 0B. PM2 PP3

The NM_006147.4(IRF6):​c.668-5T>G variant causes a splice region, splice polypyrimidine tract, intron change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a benign outcome for this variant. 2/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency: Genomes: not found (cov: 33)
• Consequence: IRF6 NM_006147.4 splice_region, splice_polypyrimidine_tract, intron
• Scores: Splicing: ADA: 0.9634
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 3.11

Genes affected

IRF6 (HGNC:6121): (interferon regulatory factor 6) This gene encodes a member of the interferon regulatory transcription factor (IRF) family. Family members share a highly-conserved N-terminal helix-turn-helix DNA-binding domain and a less conserved C-terminal protein-binding domain. The encoded protein may be a transcriptional activator. Mutations in this gene can cause van der Woude syndrome and popliteal pterygium syndrome. Mutations in this gene are also associated with non-syndromic orofacial cleft type 6. Alternate splicing results in multiple transcript variants.[provided by RefSeq, May 2011]

ACMG classification

Verdict is Uncertain_significance. Variant got 3 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: Splicing scoreres supports a deletorius effect: Scorers claiming Pathogenic: dbscSNV1_ADA, dbscSNV1_RF. Scorers claiming Uncertain: max_spliceai. No scorers claiming Benign.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
IRF6	NM_006147.4	c.668-5T>G		splice_region_variant, splice_polypyrimidine_tract_variant, intron_variant		ENST00000367021.8
IRF6	NM_001206696.2	c.383-5T>G		splice_region_variant, splice_polypyrimidine_tract_variant, intron_variant

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
IRF6	ENST00000367021.8	c.668-5T>G		splice_region_variant, splice_polypyrimidine_tract_variant, intron_variant		1	NM_006147.4	P1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 33

GnomAD4 genome Cov.: 33

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Popliteal pterygium syndrome;C1837213:Orofacial cleft 6, susceptibility to;C4551864:Van der Woude syndrome 1 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Dec 19, 2017

This sequence change falls in intron 6 of the IRF6 gene. It does not directly change the encoded amino acid sequence of the IRF6 protein. This variant is not present in population databases (ExAC no frequency). This variant has been reported in an individual affected with van der Woude syndrome (PMID: 19282774). This variant is also known as IVS6-5T>G in the literature. Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site, but this prediction has not been confirmed by published transcriptional studies. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.55
CADD	Benign	18
DANN	Benign	0.87

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	0.96
dbscSNV1_RF	Pathogenic	0.78
SpliceAI score (max)		0.27		Details are displayed if max score is > 0.2
DS_AL_spliceai		0.27		Position offset: -5

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

Publications

LitVar

Other links and lift over

dbSNP: rs1553247787; hg19: chr1-209964237;