chr6-129393069-AG-A
Variant summary
Our verdict is Pathogenic. The variant received 18 ACMG points: 18P and 0B. PVS1PM2PP5_Very_Strong
The NM_000426.4(LAMA2):c.5260delG(p.Val1754fs) variant causes a frameshift change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000335 in 1,613,782 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Pathogenic (★★). Variant results in nonsense mediated mRNA decay.
Frequency
Consequence
NM_000426.4 frameshift
Scores
Clinical Significance
Conservation
Publications
- congenital merosin-deficient muscular dystrophy 1AInheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Orphanet, Labcorp Genetics (formerly Invitae), Myriad Women’s Health, G2P
- LAMA2-related muscular dystrophyInheritance: AR Classification: DEFINITIVE Submitted by: ClinGen
- muscular dystrophy, limb-girdle, autosomal recessive 23Inheritance: AR Classification: STRONG Submitted by: Labcorp Genetics (formerly Invitae)
Genome browser will be placed here
ACMG classification
Our verdict: Pathogenic. The variant received 18 ACMG points.
Variant Effect in Transcripts
ACMG analysis was done for transcript: NM_000426.4. You can select a different transcript below to see updated ACMG assignments.
RefSeq Transcripts
| Selected | Gene | Transcript | Tags | HGVSc | HGVSp | Effect | Exon Rank | Protein | UniProt |
|---|---|---|---|---|---|---|---|---|---|
| LAMA2 | NM_000426.4 | MANE Select | c.5260delG | p.Val1754fs | frameshift | Exon 37 of 65 | NP_000417.3 | ||
| LAMA2 | NM_001079823.2 | c.5260delG | p.Val1754fs | frameshift | Exon 37 of 64 | NP_001073291.2 |
Ensembl Transcripts
| Selected | Gene | Transcript | Tags | HGVSc | HGVSp | Effect | Exon Rank | Protein | UniProt |
|---|---|---|---|---|---|---|---|---|---|
| LAMA2 | ENST00000421865.3 | TSL:5 MANE Select | c.5260delG | p.Val1754fs | frameshift | Exon 37 of 65 | ENSP00000400365.2 | ||
| LAMA2 | ENST00000618192.5 | TSL:5 | c.5524delG | p.Val1842fs | frameshift | Exon 38 of 66 | ENSP00000480802.2 | ||
| LAMA2 | ENST00000617695.5 | TSL:5 | c.5260delG | p.Val1754fs | frameshift | Exon 37 of 64 | ENSP00000481744.2 |
Frequencies
GnomAD3 genomes AF: 0.0000591 AC: 9AN: 152182Hom.: 0 Cov.: 32 show subpopulations
GnomAD2 exomes AF: 0.0000160 AC: 4AN: 249822 AF XY: 0.00000739 show subpopulations
GnomAD4 exome AF: 0.0000308 AC: 45AN: 1461600Hom.: 0 Cov.: 31 AF XY: 0.0000151 AC XY: 11AN XY: 727098 show subpopulations
Age Distribution
GnomAD4 genome AF: 0.0000591 AC: 9AN: 152182Hom.: 0 Cov.: 32 AF XY: 0.0000673 AC XY: 5AN XY: 74344 show subpopulations
Age Distribution
ClinVar
Submissions by phenotype
not provided Pathogenic:7
Nonsense variant predicted to result in protein truncation or nonsense mediated decay in a gene for which loss of function is a known mechanism of disease; Not observed at significant frequency in large population cohorts (gnomAD); This variant is associated with the following publications: (PMID: 31127727, 25663498, 37476021, 35710456)
LAMA2: PVS1, PM2, PM3
Merosin deficient congenital muscular dystrophy Pathogenic:2
This submission and the accompanying classification are no longer maintained by the submitter. For more information on current observations and classification, please contact variantquestions@myriad.com.
LAMA2-related muscular dystrophy Pathogenic:2
This sequence change creates a premature translational stop signal (p.Val1754*) in the LAMA2 gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in LAMA2 are known to be pathogenic (PMID: 18700894, 32904964). This variant is present in population databases (rs794727594, gnomAD 0.003%). This premature translational stop signal has been observed in individual(s) with congenital muscular dystrophy (PMID: 25663498). ClinVar contains an entry for this variant (Variation ID: 196993). For these reasons, this variant has been classified as Pathogenic.
Variant summary: LAMA2 c.5260delG (p.Val1754X) results in a premature termination codon, predicted to cause a truncation of the encoded protein or absence of the protein due to nonsense mediated decay, which are commonly known mechanisms for disease. The variant allele was found at a frequency of 1.6e-05 in 249822 control chromosomes. c.5260delG has been reported in the literature in at-least one individual affected with Laminin alpha 2-related dystrophy (example, Lokken_2015). At least one publication reports experimental evidence evaluating an impact on protein function. The most pronounced variant effect results in a complete absence of Merosin protein staining by IHC and western blot analysis (Lokken_2015). Three clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014 without evidence for independent evaluation. All laboratories classified the variant as pathogenic (n=2)/likely pathogenic (n=1). Based on the evidence outlined above, the variant was classified as pathogenic.
Merosin deficient congenital muscular dystrophy;C4748327:Muscular dystrophy, limb-girdle, autosomal recessive 23 Pathogenic:1
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at