rs749522728

Positions:

Variant summary

Our verdict is Pathogenic. Variant got 16 ACMG points: 16P and 0B. PVS1PP5_Very_Strong

The NM_000426.4(LAMA2):c.8244+1G>A variant causes a splice donor, intron change. The variant allele was found at a frequency of 0.00000869 in 1,611,348 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: 𝑓 0.0000066 ( 0 hom., cov: 32)

Exomes 𝑓: 0.0000089 ( 0 hom. )

Consequence

LAMA2
NM_000426.4 splice_donor, intron

Scores

Splicing: ADA: 1.000

Clinical Significance

Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:8

Conservation

PhyloP100: 6.20

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:

ENSG00000226149 (HGNC:):

ENSG00000226149 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Pathogenic. Variant got 16 ACMG points.

PVS1

Splicing +-2 bp (donor or acceptor) variant, LoF is a know mechanism of disease, No cryptic splice site detected. Exon removal results in frameshift change.

PP5

Variant 6-129492484-G-A is Pathogenic according to our data. Variant chr6-129492484-G-A is described in ClinVar as [Likely_pathogenic]. Clinvar id is 550992.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr6-129492484-G-A is described in Lovd as [Pathogenic]. Variant chr6-129492484-G-A is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	Effect	#exon/exons	MANE	Protein
LAMA2	NM_000426.4 link	c.8244+1G>A	splice_donor_variant, intron_variant		ENST00000421865.3	NP_000417.3
LAMA2	NM_001079823.2 link	c.8232+1G>A	splice_donor_variant, intron_variant			NP_001073291.2
LOC102723409	XR_001743860.2 link	n.14098C>T	splice_region_variant, non_coding_transcript_exon_variant	8/8
LOC102723409	XR_007059756.1 link	n.8569C>T	splice_region_variant, non_coding_transcript_exon_variant	11/11

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
LAMA2	ENST00000421865.3 link	c.8244+1G>A		splice_donor_variant, intron_variant		5	NM_000426.4	ENSP00000400365.2		P24043

Frequencies

GnomAD3 genomes

AF:

0.00000658

AC:

AN:

152000

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:

0.00

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.0000147

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.00000800

AC:

AN:

250124

Hom.:

AF XY:

0.00000738

AC XY:

AN XY:

135502

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:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000177

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.00000891

AC:

AN:

1459348

Hom.:

Cov.:

AF XY:

0.00000551

AC XY:

AN XY:

726150

show subpopulations

Gnomad4 AFR exome

AF:

0.0000299

Gnomad4 AMR exome

AF:

0.00

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:

0.00000901

Gnomad4 OTH exome

AF:

0.0000332

GnomAD4 genome

AF:

0.00000658

AC:

AN:

152000

Hom.:

Cov.:

AF XY:

0.0000135

AC XY:

AN XY:

74234

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:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.0000147

Gnomad4 OTH

AF:

0.00

Bravo

AF:

0.0000264

ExAC

AF:

0.00000824

AC:

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:8

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Merosin deficient congenital muscular dystrophy

Pathogenic:4

Pathogenic, criteria provided, single submitter	clinical testing	Mendelics	May 28, 2019	- -
Pathogenic, criteria provided, single submitter	clinical testing	Counsyl	Mar 23, 2017	- -
Pathogenic, criteria provided, single submitter	clinical testing	Baylor Genetics	Mar 20, 2024	- -
Pathogenic, criteria provided, single submitter	clinical testing	3billion	May 22, 2022	Substitution at the splicing junction produces an abnormal splicing effect, which is expected to cause a loss of normal protein function via nonsense-mediated mRNA decay. This variant has been reported as pathogenic more than twice (ClinVar ID: VCV000550992, 3billion database), along with assertion criteria based on the ACMG guidelines. It has been reported with an extremely low frequency in the gnomAD v2.1.1 (https://gnomad.broadinstitute.org/) dataset. Therefore, this variant is classified as pathogenic according to the recommendation of ACMG/AMP guideline. -

not provided

Pathogenic:2

Pathogenic, criteria provided, single submitter	clinical testing	Revvity Omics, Revvity	Sep 06, 2019	- -
Pathogenic, criteria provided, single submitter	clinical testing	GeneDx	Jan 12, 2021	RT-PCR studies indicate that this variant leads to complete skipping of exon 58 in the LAMA2 gene and results in a significant decrease in mRNA levels (Siala et al., 2007); Canonical splice site variant predicted to result in a null allele in a gene for which loss-of-function is a known mechanism of disease; Not observed at a significant frequency in large population cohorts (Lek et al., 2016); This variant is associated with the following publications: (PMID: 17949279, 19388593, 18700894, 20207543, 30055037, 25525159) -

LAMA2-related muscular dystrophy

Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Oct 22, 2023

This sequence change affects a donor splice site in intron 58 of the LAMA2 gene. RNA analysis indicates that disruption of this splice site induces altered splicing and may result in an absent or disrupted protein product. This variant is present in population databases (rs749522728, gnomAD 0.0009%). Disruption of this splice site has been observed in individuals with congenital muscular dystrophy (PMID: 17949279, 19388593, 20207543, 30055037). This variant is also known as IVS58+1G>A. ClinVar contains an entry for this variant (Variation ID: 550992). Studies have shown that disruption of this splice site results in skipping of exon 58 and introduces a premature termination codon (PMID: 17949279). The resulting mRNA is expected to undergo nonsense-mediated decay. For these reasons, this variant has been classified as Pathogenic. -

Merosin deficient congenital muscular dystrophy;C4748327:Muscular dystrophy, limb-girdle, autosomal recessive 23

Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

Fulgent Genetics, Fulgent Genetics

Oct 31, 2018

- -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

BayesDel_addAF

Pathogenic

0.63

BayesDel_noAF

Pathogenic

0.19

CADD

Uncertain

DANN

Uncertain

0.99

Eigen

Pathogenic

1.0

Eigen_PC

Pathogenic

0.83

FATHMM_MKL

Uncertain

0.96

GERP RS

5.6

Splicing

Name

Calibrated prediction

Score

Prediction

dbscSNV1_ADA

Pathogenic

1.0

dbscSNV1_RF

Pathogenic

0.93

SpliceAI score (max)

0.87

Details are displayed if max score is > 0.2

DS_DL_spliceai

0.87

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