12-55699990-C-T

Position:

chr12-55699990-C-T

Variant summary

Our verdict is Uncertain significance. Variant got 5 ACMG points: 5P and 0B. PVS1_ModeratePM2PP5

The NM_002206.3(ITGA7):c.671-1G>A variant causes a splice acceptor, intron change. The variant allele was found at a frequency of 0.0000223 in 1,613,858 control chromosomes in the GnomAD database, including 1 homozygotes. 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 Conflicting classifications of pathogenicity (no stars).

Frequency

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

Exomes 𝑓: 0.000024 ( 1 hom. )

Consequence

ITGA7
NM_002206.3 splice_acceptor, intron

Scores

Splicing: ADA: 0.9518

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:1U:2

Conservation

PhyloP100: 7.12

Variant links:

Genes affected

ITGA7 (HGNC:6143): (integrin subunit alpha 7) The protein encoded by this gene belongs to the integrin alpha chain family. Integrins are heterodimeric integral membrane proteins composed of an alpha chain and a beta chain. They mediate a wide spectrum of cell-cell and cell-matrix interactions, and thus play a role in cell migration, morphologic development, differentiation, and metastasis. This protein functions as a receptor for the basement membrane protein laminin-1. It is mainly expressed in skeletal and cardiac muscles and may be involved in differentiation and migration processes during myogenesis. Defects in this gene are associated with congenital myopathy. Alternatively spliced transcript variants encoding different isoforms have been noted for this gene. [provided by RefSeq, Feb 2009]

ITGA7 links:

ITGA7 (HGNC:):

ITGA7 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Uncertain_significance. Variant got 5 ACMG points.

PVS1

Splicing +-2 bp (donor or acceptor) variant, product NOT destroyed by NMD, known LOF gene, truncates exone, which is 0.034856472 fraction of the gene. Cryptic splice site detected, with MaxEntScore 4.3, offset of 1, new splice context is: ctcaccccaccccccacaAGgtt. Cryptic site results in frameshift change. If cryptic site found is not functional and variant results in exon loss, it results in inframe change.

PM2

Very rare variant in population databases, with high coverage;

PP5

Variant 12-55699990-C-T is Pathogenic according to our data. Variant chr12-55699990-C-T is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 571500.We mark this variant Likely_pathogenic, oryginal submissions are: {Uncertain_significance=1, Likely_pathogenic=1}.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
ITGA7	NM_002206.3 linkuse as main transcript	c.671-1G>A		splice_acceptor_variant, intron_variant		ENST00000257879.11	NP_002197.2	Q13683-7Q4LE35

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
ITGA7	ENST00000257879.11 linkuse as main transcript	c.671-1G>A		splice_acceptor_variant, intron_variant		1	NM_002206.3	ENSP00000257879.7		Q13683-7

Frequencies

GnomAD3 genomes

AF:

0.00000658

AC:

AN:

152014

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:

0.000207

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.00

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.0000438

AC:

AN:

251002

Hom.:

AF XY:

0.0000663

AC XY:

AN XY:

135746

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 SAS exome

AF:

0.000359

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000239

AC:

AN:

1461844

Hom.:

Cov.:

AF XY:

0.0000399

AC XY:

AN XY:

727222

show subpopulations

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:

0.000394

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

8.99e-7

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

AF:

0.00000658

AC:

AN:

152014

Hom.:

Cov.:

AF XY:

0.0000135

AC XY:

AN XY:

74244

show subpopulations

Gnomad4 AFR

AF:

0.00

Gnomad4 AMR

AF:

0.00

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.000207

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.00

Gnomad4 OTH

AF:

0.00

ExAC

AF:

0.0000659

AC:

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:1Uncertain:2

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

Congenital muscular dystrophy due to integrin alpha-7 deficiency

Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Feb 14, 2019

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. Donor and acceptor splice site variants typically lead to a loss of protein function (PMID: 16199547), and loss-of-function variants in ITGA7 are known to be pathogenic (PMID: 9590299). This variant has not been reported in the literature in individuals with ITGA7-related disease. This variant is present in population databases (rs777049999, ExAC 0.05%). This sequence change affects an acceptor splice site in intron 4 of the ITGA7 gene. It is expected to disrupt RNA splicing and likely results in an absent or disrupted protein product. -

ITGA7-related disorder

Uncertain:1

Uncertain significance, no assertion criteria provided

clinical testing

PreventionGenetics, part of Exact Sciences

Nov 16, 2023

The ITGA7 c.671-1G>A variant is predicted to disrupt the AG splice acceptor site and interfere with normal splicing. However, there is possibly an alternative AG acceptor site created and we cannot be certain of the biological impact of this variant. To our knowledge, this variant has not been reported in the literature. This variant is reported in 0.036% of alleles in individuals of South Asian descent in gnomAD, including one homozygous individual. Although we suspect that this variant may be pathogenic, at this time, the clinical significance of this variant is uncertain due to the absence of conclusive functional and genetic evidence. -

not provided

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

GeneDx

Jun 30, 2022

Canonical splice site variant expected to result in aberrant splicing, although in the absence of functional evidence the actual effect of this sequence change is unknown.; Has not been previously published as pathogenic or benign to our knowledge -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

BayesDel_addAF

Pathogenic

0.40

BayesDel_noAF

Benign

-0.22

CADD

Pathogenic

DANN

Uncertain

0.99

Eigen

Uncertain

0.39

Eigen_PC

Uncertain

0.45

FATHMM_MKL

Uncertain

0.94

GERP RS

4.7

Splicing

Name

Calibrated prediction

Score

Prediction

dbscSNV1_ADA

Benign

0.95

dbscSNV1_RF

Pathogenic

0.83

SpliceAI score (max)

0.95

Details are displayed if max score is > 0.2

DS_AG_spliceai

0.74

Position offset: -2

DS_AL_spliceai

0.95

Position offset: -1

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

Publications

LitVar

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over