NM_000426.4:c.5256_5259dupAAAA

Variant names:

• chr6-129393063-G-GAAAA
• rs1211739649
• NM_000426.4:c.5256_5259dupAAAA

Variant summary

Our verdict is Pathogenic. The variant received 10 ACMG points: 10P and 0B. PVS1 PM2

The NM_000426.4(LAMA2):​c.5256_5259dupAAAA​(p.Val1754LysfsTer14) variant causes a frameshift change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Variant results in nonsense mediated mRNA decay.

• Frequency: Genomes: not found (cov: 32)
• Consequence: LAMA2 NM_000426.4 frameshift
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 1.95
• Publications: 0 publications found

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 Gene-Disease associations (from GenCC):

• congenital merosin-deficient muscular dystrophy 1A

  Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Orphanet, Labcorp Genetics (formerly Invitae), Myriad Women’s Health, G2P
• LAMA2-related muscular dystrophy

  Inheritance: AR Classification: DEFINITIVE Submitted by: ClinGen
• muscular dystrophy, limb-girdle, autosomal recessive 23

  Inheritance: AR Classification: STRONG Submitted by: Labcorp Genetics (formerly Invitae)

ACMG classification

Our verdict: Pathogenic. The variant received 10 ACMG points.

• PVS1: Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
• PM2: Very rare variant in population databases, with high coverage

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
LAMA2	NM_000426.4	c.5256_5259dupAAAA	p.Val1754LysfsTer14	frameshift_variant	Exon 37 of 65	ENST00000421865.3	NP_000417.3
LAMA2	NM_001079823.2	c.5256_5259dupAAAA	p.Val1754LysfsTer14	frameshift_variant	Exon 37 of 64		NP_001073291.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
LAMA2	ENST00000421865.3	c.5256_5259dupAAAA	p.Val1754LysfsTer14	frameshift_variant	Exon 37 of 65	5	NM_000426.4	ENSP00000400365.2
LAMA2	ENST00000618192.5	c.5520_5523dupAAAA	p.Val1842LysfsTer14	frameshift_variant	Exon 38 of 66	5		ENSP00000480802.2
LAMA2	ENST00000617695.5	c.5256_5259dupAAAA	p.Val1754LysfsTer14	frameshift_variant	Exon 37 of 64	5		ENSP00000481744.2
LAMA2	ENST00000687590.1	n.1676_1679dupAAAA		non_coding_transcript_exon_variant	Exon 5 of 5

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 32

Alfa AF: 0.00 Hom.: 0

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
PhyloP100		2.0
Mutation Taster		=5/195	disease causing (fs/PTC)

Splicing

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

Other links and lift over

dbSNP: rs1211739649; hg19: chr6-129714208;