rs35130237
Variant summary
Our verdict is Benign. The variant received -7 ACMG points: 2P and 9B. PM1BP4_StrongBP6BS2
The NM_000023.4(SGCA):c.421C>A(p.Arg141Ser) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000813 in 1,589,732 control chromosomes in the GnomAD database, including 4 homozygotes. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R141H) has been classified as Uncertain significance.
Frequency
Consequence
NM_000023.4 missense
Scores
Clinical Significance
Conservation
Publications
- autosomal recessive limb-girdle muscular dystrophyInheritance: AR Classification: DEFINITIVE Submitted by: ClinGen
- autosomal recessive limb-girdle muscular dystrophy type 2DInheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Labcorp Genetics (formerly Invitae), Myriad Women’s Health, Laboratory for Molecular Medicine, Orphanet
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ACMG classification
Our verdict: Benign. The variant received -7 ACMG points.
Transcripts
RefSeq
| Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | MANE | Protein | UniProt |
|---|---|---|---|---|---|---|---|---|
| SGCA | NM_000023.4 | c.421C>A | p.Arg141Ser | missense_variant | Exon 5 of 10 | ENST00000262018.8 | NP_000014.1 | |
| SGCA | NM_001135697.3 | c.421C>A | p.Arg141Ser | missense_variant | Exon 5 of 8 | NP_001129169.1 | ||
| SGCA | NR_135553.2 | n.457C>A | non_coding_transcript_exon_variant | Exon 5 of 9 |
Ensembl
Frequencies
GnomAD3 genomes AF: 0.000585 AC: 89AN: 152144Hom.: 0 Cov.: 32 show subpopulations
GnomAD2 exomes AF: 0.000596 AC: 125AN: 209650 AF XY: 0.000559 show subpopulations
GnomAD4 exome AF: 0.000837 AC: 1203AN: 1437470Hom.: 4 Cov.: 33 AF XY: 0.000810 AC XY: 577AN XY: 712550 show subpopulations
Age Distribution
GnomAD4 genome AF: 0.000585 AC: 89AN: 152262Hom.: 0 Cov.: 32 AF XY: 0.000578 AC XY: 43AN XY: 74444 show subpopulations
Age Distribution
ClinVar
Submissions by phenotype
Autosomal recessive limb-girdle muscular dystrophy type 2D Uncertain:4Benign:2
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The SGCA c.421C>A; p.Arg141Ser variant (rs35130237) is reported in the literature in several individuals affected with limb-girdle muscular dystrophy or a related sarcoglycanopathy, although a second SGCA variant was not detected in affected individuals (Boito 2003, Trabelsi 2008). The p.Arg141Ser variant is found in the Latino population with an allele frequency of 0.11% (33/31084 alleles) in the Genome Aggregation Database, and it is reported in ClinVar (Variation ID: 197618). The arginine at codon 141 is weakly conserved, and computational analyses (SIFT, PolyPhen-2) predict that this variant is tolerated. However, computational analyses of splicing (Alamut v.2.11) predict that this variant may impact splicing by creating a novel cryptic donor splice site, although RNA analyses would be required to confirm this. Given the lack of clinical and functional data, the significance of the p.Arg141Ser variant is uncertain at this time. References: Boito C et al. Novel sarcoglycan gene mutations in a large cohort of Italian patients. J Med Genet. 2003 May;40(5):e67. Trabelsi M et al. Revised spectrum of mutations in sarcoglycanopathies. Eur J Hum Genet. 2008 Jul;16(7):793-803. -
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not provided Uncertain:5
Observed in a patient in the published literature (Boito et al., 2003) with limb-girdle muscular dystrophy who did not have another pathogenic SGCA variant; however, this patient had only mild reduction in alpha-sarcoglycan and normal beta-, delta-, and gamma-sarcoglycan proteins on immunoblot screning on muscle biopsy and Western blot of muscle protein showed a 40% reduction in alpha-sarcoglycan protein; In silico analysis supports that this missense variant does not alter protein structure/function; However, in silico analysis supports this missense variant has a deleterious effect on splicing; This variant is associated with the following publications: (PMID: 18285821, 12746421, 24742800, 31931849) -
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Cardiomyopathy Benign:1
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Sarcoglycanopathy Benign:1
This variant was observed as part of a predisposition screen in an ostensibly healthy population. A literature search was performed for the gene, cDNA change, and amino acid change (where applicable). Publications were found based on this search. The evidence from the literature, in combination with allele frequency data from public databases where available, was sufficient to determine this variant is unlikely to cause disease. Therefore, this variant is classified as likely benign. -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at