rs182064878
Variant summary
Our verdict is Likely benign. Variant got -4 ACMG points: 0P and 4B. BS2
The NM_000426.4(LAMA2):c.6268+5G>C variant causes a splice region, intron change. The variant allele was found at a frequency of 0.00098 in 1,610,274 control chromosomes in the GnomAD database, including 3 homozygotes. 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 Uncertain significance (★★).
Frequency
Consequence
NM_000426.4 splice_region, intron
Scores
Clinical Significance
Conservation
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ACMG classification
Verdict is Likely_benign. Variant got -4 ACMG points.
Transcripts
RefSeq
Ensembl
Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | TSL | MANE | Protein | Appris | UniProt |
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LAMA2 | ENST00000421865.3 | c.6268+5G>C | splice_region_variant, intron_variant | Intron 43 of 64 | 5 | NM_000426.4 | ENSP00000400365.2 | |||
LAMA2 | ENST00000618192.5 | c.6532+5G>C | splice_region_variant, intron_variant | Intron 44 of 65 | 5 | ENSP00000480802.2 | ||||
LAMA2 | ENST00000617695.5 | c.6268+5G>C | splice_region_variant, intron_variant | Intron 43 of 63 | 5 | ENSP00000481744.2 | ||||
ENSG00000226149 | ENST00000665046.1 | n.1225C>G | non_coding_transcript_exon_variant | Exon 10 of 10 |
Frequencies
GnomAD3 genomes AF: 0.000664 AC: 101AN: 152166Hom.: 1 Cov.: 32
GnomAD3 exomes AF: 0.000674 AC: 169AN: 250604Hom.: 0 AF XY: 0.000590 AC XY: 80AN XY: 135480
GnomAD4 exome AF: 0.00101 AC: 1477AN: 1457990Hom.: 2 Cov.: 30 AF XY: 0.000985 AC XY: 715AN XY: 725640
GnomAD4 genome AF: 0.000663 AC: 101AN: 152284Hom.: 1 Cov.: 32 AF XY: 0.000537 AC XY: 40AN XY: 74464
ClinVar
Submissions by phenotype
not provided Uncertain:6
In silico analysis, which includes splice predictors and evolutionary conservation, supports a deleterious effect; Has not been previously published as pathogenic or benign to our knowledge -
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PP3 -
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not specified Uncertain:2
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Variant summary: LAMA2 c.6268+5G>C alters a conserved nucleotide located close to a canonical splice site and therefore could affect mRNA splicing, leading to a significantly altered protein sequence. Several computational tools predict a significant impact on normal splicing: Four predict the variant abolishes a 5' splicing donor site. However, these predictions have yet to be confirmed by functional studies. The variant allele was found at a frequency of 0.00098 in 1603308 control chromosomes in the gnomAD database (v4.0 dataset), including 3 homozygotes. This frequency is not higher than the estimated maximum expected for a pathogenic variant in LAMA2 causing Laminin Alpha 2-Related Dystrophy (0.0022), allowing no conclusion about variant significance. The variant, c.6268+5G>C, has been listed to be found in a validation study in an individual affected with muscular dystrophy, however no further details were provided (Valencia_2012). These report(s) do not provide unequivocal conclusions about association of the variant with Laminin Alpha 2-Related Dystrophy. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. Ten submitters have cited clinical-significance assessments for this variant to ClinVar after 2014. All submitters classified the variant as uncertain significance. Based on the evidence outlined above, the variant was classified as uncertain significance. -
Inborn genetic diseases Uncertain:1
The c.6268+5G>C intronic alteration consists of a G to C substitution nucleotides after coding exon 43 in the LAMA2 gene. Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -
LAMA2-related muscular dystrophy Uncertain:1
This sequence change falls in intron 43 of the LAMA2 gene. It does not directly change the encoded amino acid sequence of the LAMA2 protein. It affects a nucleotide within the consensus splice site. This variant is present in population databases (rs182064878, gnomAD 0.2%), and has an allele count higher than expected for a pathogenic variant. This variant has not been reported in the literature in individuals affected with LAMA2-related conditions. ClinVar contains an entry for this variant (Variation ID: 284415). Variants that disrupt the consensus splice site are a relatively common cause of aberrant splicing (PMID: 17576681, 9536098). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -
Congenital muscular dystrophy due to partial LAMA2 deficiency Uncertain:1
This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score, this variant could not be ruled out of causing disease and therefore its association with disease required further investigation. A literature search was performed for the gene, cDNA change, and amino acid change (if applicable). No publications were found based on this search. This variant was therefore classified as a variant of unknown significance for this disease. -
Merosin deficient congenital muscular dystrophy;C4748327:Muscular dystrophy, limb-girdle, autosomal recessive 23 Uncertain:1
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LAMA2-related disorder Benign:1
This variant is classified as likely benign based on ACMG/AMP sequence variant interpretation guidelines (Richards et al. 2015 PMID: 25741868, with internal and published modifications). -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at