4-78478063-T-A

Position:

• chr4-78478063-T-A

Variant summary

Our verdict is Pathogenic. Variant got 22 ACMG points: 22P and 0B. PVS1 PM2 PP3_Strong PP5_Very_Strong

The NM_025074.7(FRAS1):​c.8098+2T>A variant causes a splice donor change. The variant allele was found at a frequency of 0.000000712 in 1,403,618 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: 33)
  • Exomes 𝑓: 7.1e-7 (0 hom.)
• Consequence: FRAS1 NM_025074.7 splice_donor
• Scores: Splicing: ADA: 1.000
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:2
• Conservation: PhyloP100: 7.11

Genes affected

FRAS1 (HGNC:19185): (Fraser extracellular matrix complex subunit 1) This gene encodes an extracellular matrix protein that appears to function in the regulation of epidermal-basement membrane adhesion and organogenesis during development. Mutations in this gene cause Fraser syndrome, a multisystem malformation that can include craniofacial, urogenital and respiratory system abnormalities. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Oct 2009]

ACMG classification

Verdict is Pathogenic. Variant got 22 ACMG points.

• PVS1: Splicing +-2 bp (donor or acceptor) variant, LoF is a know mechanism of disease, Cryptic splice site detected, with MaxEntScore 5.5, offset of 17, new splice context is: cagGTgaca. Cryptic site results in frameshift change. If cryptic site found is not functional and variant results in exon loss, it results in frameshift change.
• PM2: Very rare variant in population databases, with high coverage
• PP3: Splicing scoreres supports a deletorius effect: Scorers claiming Pathogenic: dbscSNV1_ADA, dbscSNV1_RF, max_spliceai. No scorers claiming Uncertain. No scorers claiming Benign.
• PP5: Variant 4-78478063-T-A is Pathogenic according to our data. Variant chr4-78478063-T-A is described in ClinVar as [Likely_pathogenic]. Clinvar id is 191192.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
FRAS1	NM_025074.7	c.8098+2T>A		splice_donor_variant		ENST00000512123.4

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
FRAS1	ENST00000512123.4	c.8098+2T>A		splice_donor_variant		5	NM_025074.7	P1
FRAS1	ENST00000682513.1	c.8098+2T>A		splice_donor_variant

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 7.12e-7 AC: 1 AN: 1403618 Hom.: 0 Cov.: 31 AF XY: 0.00000144 AC XY: 1 AN XY: 692404

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.0000126

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 33

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Inborn genetic diseases Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Ambry Genetics

May 24, 2022

The c.8098+2T>A intronic variant results from a T to A substitution two nucleotides after coding exon 55 of the FRAS1 gene. Alterations that disrupt the canonical splice site are expected to cause aberrant splicing, resulting in an abnormal protein or a transcript that is subject to nonsense-mediated mRNA decay. This variant was not reported in population-based cohorts in the Genome Aggregation Database (gnomAD). This nucleotide position is highly conserved in available vertebrate species. In silico splice site analysis predicts that this alteration will weaken the native splice donor site and will result in the creation or strengthening of a novel splice donor site. Based on the available evidence, this alteration is classified as pathogenic. -

not provided Pathogenic:1

Likely pathogenic, criteria provided, single submitter

research

Center for Genomic Medicine, King Faisal Specialist Hospital and Research Center

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Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.63	D
BayesDel_noAF	Uncertain	0.020
CADD	Pathogenic	33
DANN	Benign	0.97
Eigen	Pathogenic	1.0
Eigen_PC	Pathogenic	0.81
FATHMM_MKL	Pathogenic	0.99	D
MutationTaster	Benign	1.0	D
GERP RS		5.7

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.88
SpliceAI score (max)		0.99		Details are displayed if max score is > 0.2
DS_DG_spliceai		0.65		Position offset: 15
DS_DL_spliceai		0.99		Position offset: -2

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

Publications

LitVar

Other links and lift over

dbSNP: rs786205570; hg19: chr4-79399217;