rs1555163357

Positions:

• chr12-55698562-A-T

Variant summary

Our verdict is Uncertain significance. Variant got 4 ACMG points: 4P and 0B. PM2 PP3_Moderate

The NM_002206.3(ITGA7):​c.1013T>A​(p.Ile338Lys) variant causes a missense change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. I338V) has been classified as Uncertain significance.

• Frequency: Genomes: not found (cov: 32)
• Consequence: ITGA7 NM_002206.3 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 7.45

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]

ACMG classification

Verdict is Uncertain_significance. Variant got 4 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.935

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
ITGA7	NM_002206.3	c.1013T>A	p.Ile338Lys	missense_variant	7/25	ENST00000257879.11

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
ITGA7	ENST00000257879.11	c.1013T>A	p.Ile338Lys	missense_variant	7/25	1	NM_002206.3	A1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 33

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Congenital muscular dystrophy due to integrin alpha-7 deficiency Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Dec 24, 2016

In summary, this variant is a novel missense change with uncertain impact on protein function. It has been classified as a Variant of Uncertain Significance. Algorithms developed to predict the effect of missense changes on protein structure and function (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be disruptive, but these predictions have not been confirmed by published functional studies. This variant is not present in population databases (ExAC no frequency) and has not been reported in the literature in individuals with a ITGA7-related disease. This sequence change replaces isoleucine with lysine at codon 338 of the ITGA7 protein (p.Ile338Lys). The isoleucine residue is moderately conserved and there is a moderate physicochemical difference between isoleucine and lysine. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.98
BayesDel_addAF	Pathogenic	0.21	D
BayesDel_noAF	Uncertain	0.060
CADD	Pathogenic	27
DANN	Benign	0.96
DEOGEN2	Uncertain	0.60	.;.;D;.;D
Eigen	Uncertain	0.55
Eigen_PC	Uncertain	0.55
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Uncertain	0.89	D;D;D;D;T
M_CAP	Uncertain	0.16	D
MetaRNN	Pathogenic	0.93	D;D;D;D;D
MetaSVM	Uncertain	0.027	D
MutationAssessor	Pathogenic	3.1	.;.;.;.;M
MutationTaster	Benign	1.0	D;D;D;D;D;D;D;D
PrimateAI	Benign	0.37	T
PROVEAN	Pathogenic	-4.9	D;D;D;D;D
REVEL	Pathogenic	0.65
Sift	Uncertain	0.0010	D;D;D;D;D
Sift4G	Pathogenic	0.0010	D;D;D;D;D
Polyphen		0.36	B;.;.;P;B
Vest4		0.64
MutPred		0.89		.;.;.;.;Gain of ubiquitination at I382 (P = 0.0369);
MVP		0.94
MPC		0.46
ClinPred		1.0	D
GERP RS		4.9
Varity_R		0.69
gMVP		0.92

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.020		Details are displayed if max score is > 0.2

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

Publications

LitVar

Other links and lift over

dbSNP: rs1555163357; hg19: chr12-56092346;