rs398123378
Variant summary
Our verdict is Pathogenic. The variant received 18 ACMG points: 18P and 0B. PVS1PM2PP5_Very_Strong
The NM_000426.4(LAMA2):c.5914C>T(p.Gln1972*) variant causes a stop gained change. The variant allele was found at a frequency of 0.00000434 in 1,613,716 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Pathogenic (★★). Variant results in nonsense mediated mRNA decay.
Frequency
Consequence
NM_000426.4 stop_gained
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)
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ACMG classification
Our verdict: Pathogenic. The variant received 18 ACMG points.
Transcripts
RefSeq
Ensembl
| Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | TSL | MANE | Protein | Appris | UniProt |
|---|---|---|---|---|---|---|---|---|---|---|
| LAMA2 | ENST00000421865.3 | c.5914C>T | p.Gln1972* | stop_gained | Exon 41 of 65 | 5 | NM_000426.4 | ENSP00000400365.2 | ||
| LAMA2 | ENST00000618192.5 | c.6178C>T | p.Gln2060* | stop_gained | Exon 42 of 66 | 5 | ENSP00000480802.2 | |||
| LAMA2 | ENST00000617695.5 | c.5914C>T | p.Gln1972* | stop_gained | Exon 41 of 64 | 5 | ENSP00000481744.2 |
Frequencies
GnomAD3 genomes AF: 0.0000197 AC: 3AN: 152152Hom.: 0 Cov.: 32 show subpopulations
GnomAD4 exome AF: 0.00000274 AC: 4AN: 1461564Hom.: 0 Cov.: 30 AF XY: 0.00 AC XY: 0AN XY: 727106 show subpopulations
GnomAD4 genome AF: 0.0000197 AC: 3AN: 152152Hom.: 0 Cov.: 32 AF XY: 0.0000269 AC XY: 2AN XY: 74314 show subpopulations
Age Distribution
ClinVar
Submissions by phenotype
not provided Pathogenic:3
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: 30055037) -
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Merosin deficient congenital muscular dystrophy Pathogenic:2
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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.Gln1972*) 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 not present in population databases (gnomAD no frequency). This premature translational stop signal has been observed in individuals with congenital muscular dystrophy (PMID: 30055037; internal data). ClinVar contains an entry for this variant (Variation ID: 92971). For these reasons, this variant has been classified as Pathogenic. -
Variant summary: LAMA2 c.5914C>T (p.Gln1972X) 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. Truncations downstream of this position have been classified as pathogenic in the literature (Oliveira_2018). The variant was absent in 251280 control chromosomes. c.5914C>T has been reported in the literature in individuals affected with Laminin alpha 2-related dystrophy (example, Oliveira_2018). These data indicate that the variant is likely to be associated with disease. At least one publication reports experimental evidence evaluating an impact on protein function. The most pronounced variant effect results in a deficiency of laminin-alpha-2 by IHC in muscle/fibroblasts of affected patients (Oliveira_2018). Two 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=1)/likely pathogenic(n=1). Based on the evidence outlined above, the variant was classified as pathogenic. -
Inborn genetic diseases Pathogenic:1
The c.5914C>T (p.Q1972*) alteration, located in exon 41 (coding exon 41) of the LAMA2 gene, consists of a C to T substitution at nucleotide position 5914. This changes the amino acid from a glutamine (Q) to a stop codon at amino acid position 1972. This alteration is expected to result in loss of function by premature protein truncation or nonsense-mediated mRNA decay. Based on data from the Genome Aggregation Database (gnomAD), the LAMA2 c.5914C>T alteration was not observed, with coverage at this position. This variant has been detected in a homozygous state in at least two individuals, one with a congenital muscular dystrophy phenotype and the other with an undescribed phenotype. It has also been detected in at least one individual in a heterozygous state with no second deleterious variant being found; however, this individual's phenotype was not described (Oliveira, 2018). Based on the available evidence, this alteration is classified as pathogenic. -
Merosin deficient congenital muscular dystrophy;C4748327:Muscular dystrophy, limb-girdle, autosomal recessive 23 Pathogenic:1
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Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at