Variant chr6-129460329-G-A details in Genebe, Genetics Data Aggregator

Variant summary

Our verdict is Uncertain significance. Variant got 1 ACMG points: 1P and 0B. PP5

The NM_000426.4(LAMA2):c.6992+5G>A variant causes a splice donor 5th base, intron change. The variant allele was found at a frequency of 0.0000103 in 1,459,702 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

Frequency

Genomes: not found (cov: 32)

Exomes 𝑓: 0.000010 ( 0 hom. )

Consequence

LAMA2
NM_000426.4 splice_donor_5th_base, intron

Scores

Splicing: ADA: 0.9997

Clinical Significance

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

Conservation

PhyloP100: 4.69

Variant links:

Genes affected

LAMA2 (HGNC:6482): (laminin subunit alpha 2) Laminin, an extracellular protein, is a major component of the basement membrane. It is thought to mediate the attachment, migration, and organization of cells into tissues during embryonic development by interacting with other extracellular matrix components. It is composed of three subunits, alpha, beta, and gamma, which are bound to each other by disulfide bonds into a cross-shaped molecule. This gene encodes the alpha 2 chain, which constitutes one of the subunits of laminin 2 (merosin) and laminin 4 (s-merosin). Mutations in this gene have been identified as the cause of congenital merosin-deficient muscular dystrophy. Two transcript variants encoding different proteins have been found for this gene. [provided by RefSeq, Jul 2008]

LAMA2 links:

(HGNC:):

links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Uncertain_significance. Variant got 1 ACMG points.

PP5

Variant 6-129460329-G-A is Pathogenic according to our data. Variant chr6-129460329-G-A is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 546142.We mark this variant Likely_pathogenic, oryginal submissions are: {Likely_pathogenic=1, Uncertain_significance=2}.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
LAMA2	NM_000426.4 linkuse as main transcript	c.6992+5G>A		splice_donor_5th_base_variant, intron_variant		ENST00000421865.3	NP_000417.3
LAMA2	NM_001079823.2 linkuse as main transcript	c.6992+5G>A		splice_donor_5th_base_variant, intron_variant			NP_001073291.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
LAMA2	ENST00000421865.3 linkuse as main transcript	c.6992+5G>A		splice_donor_5th_base_variant, intron_variant		5	NM_000426.4	ENSP00000400365
	ENST00000665046.1 linkuse as main transcript	n.976-19077C>T		intron_variant, non_coding_transcript_variant

Frequencies

GnomAD3 genomes

Cov.:

GnomAD3 exomes

AF:

0.00000399

AC:

AN:

250460

Hom.:

AF XY:

0.00

AC XY:

AN XY:

135356

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.0000290

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad SAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000103

AC:

AN:

1459702

Hom.:

Cov.:

AF XY:

0.00000688

AC XY:

AN XY:

726256

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.0000224

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.00

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.0000117

Gnomad4 OTH exome

AF:

0.0000166

GnomAD4 genome

Cov.:

Bravo

AF:

0.00000378

EpiCase

AF:

0.00

EpiControl

AF:

0.0000593

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:2Uncertain:2

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

not provided

Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

GeneDx

May 29, 2018

The c.6992+5G>A variant in the LAMA2 gene has been reported previously in the heterozygous state with a second LAMA2 variant in an individual with limb girdle muscular dystrophy, however, segregation studies to confirm phase were only performed on one parent (Harris et al., 2017). This variant is predicted to destroy the splice donor site in intron 49. Both in silico predictors and evolutionary conservation support a deleterious effect in this gene for which loss-of-function is a known mechanism for disease. The c.6992+5G>A variant is not observed at a significant frequency in large population cohorts (Lek et al., 2016). We interpret c.6992+5G>A as a likely pathogenic variant. -

Muscular dystrophy, limb-girdle, autosomal recessive 23

Pathogenic:1

Likely pathogenic, no assertion criteria provided

clinical testing

Institute of Human Genetics, University of Wuerzburg

- -

Merosin deficient congenital muscular dystrophy

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Counsyl

Mar 01, 2018

- -

LAMA2-related disorder

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

PreventionGenetics, part of Exact Sciences

Mar 20, 2023

The LAMA2 c.6992+5G>A variant is predicted to interfere with splicing. This variant has been reported in the heterozygous state (along with a second variant) in an individual with white matter changes (Table 1, individual 32, Harris et al. 2017. PubMed ID: 28877744). A skin biopsy for this individual demonstrated partial absence of laminin a2. In the gnomAD public population database this variant has been reported in one of ~250,000 alleles (https://gnomad.broadinstitute.org/variant/6-129781474-G-A), and is interpreted as uncertain significance and likely pathogenic in ClinVar (https://www.ncbi.nlm.nih.gov/clinvar/variation/546142/). At this time, the clinical significance of this variant is uncertain due to the absence of conclusive functional and genetic evidence. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

BayesDel_noAF

Benign

-0.68

CADD

Benign

DANN

Benign

0.73

Splicing

Name

Calibrated prediction

Score

Prediction

dbscSNV1_ADA

Pathogenic

1.0

dbscSNV1_RF

Pathogenic

0.94

SpliceAI score (max)

0.80

Details are displayed if max score is > 0.2

DS_DL_spliceai

0.80

Position offset: -5

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