rs397516338
Variant summary
Our verdict is Benign. Variant got -7 ACMG points: 2P and 9B. PM2BP4_StrongBP6BS1
The NM_000337.6(SGCD):āc.848A>Gā(p.Gln283Arg) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000179 in 1,611,148 control chromosomes in the GnomAD database, including 1 homozygotes. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).
Frequency
Consequence
NM_000337.6 missense
Scores
Clinical Significance
Conservation
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ACMG classification
Verdict is Benign. Variant got -7 ACMG points.
Transcripts
RefSeq
Ensembl
Frequencies
GnomAD3 genomes AF: 0.000197 AC: 30AN: 152146Hom.: 0 Cov.: 32
GnomAD3 exomes AF: 0.000556 AC: 138AN: 248152Hom.: 0 AF XY: 0.000475 AC XY: 64AN XY: 134624
GnomAD4 exome AF: 0.000178 AC: 259AN: 1458884Hom.: 1 Cov.: 30 AF XY: 0.000159 AC XY: 115AN XY: 725344
GnomAD4 genome AF: 0.000197 AC: 30AN: 152264Hom.: 0 Cov.: 32 AF XY: 0.000188 AC XY: 14AN XY: 74450
ClinVar
Submissions by phenotype
not provided Uncertain:2Benign:1
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In silico analysis, which includes protein predictors and evolutionary conservation, supports that this variant does not alter protein structure/function; This variant is associated with the following publications: (PMID: 32344918, 26720722, 23861362, 27707468) -
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not specified Benign:2
p.Gln283Arg in exon 9 of SGCD: This variant is not expected to have clinical sig nificance because it has been identified in 0.6% (57/8734) of East Asian chromos omes by the Exome Aggregation Consortium (ExAC, http://exac.broadinstitute.org; dbSNP rs397516338). -
Variant summary: SGCD c.848A>G (p.Gln283Arg) results in a conservative amino acid change in the encoded protein sequence. Three of five in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 0.00056 in 248152 control chromosomes (gnomAD), predominantly at a frequency of 0.0076 within the East Asian subpopulation in the gnomAD database. The observed variant frequency within East Asian control individuals in the gnomAD database is approximately 11 fold of the estimated maximal expected allele frequency for a pathogenic variant in SGCD causing Limb-Girdle Muscular Dystrophy, Autosomal Recessive phenotype (0.00072), strongly suggesting that the variant is a benign polymorphism found primarily in populations of East Asian origin. To our knowledge, no occurrence of c.848A>G in individuals affected with Limb-Girdle Muscular Dystrophy, Autosomal Recessive has been reported. One publication has found that the variant protein interacts with other SGC proteins in an identical manner as wild-type, although there is reduced cell surface expression of the complete SGC complex (Chen_2015). Five ClinVar submitters have assessed the variant since 2014: all five classified the variant as likely benign. Based on the evidence outlined above, the variant was classified as likely benign. -
SGCD-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). -
Autosomal recessive limb-girdle muscular dystrophy type 2F Benign:1
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Qualitative or quantitative defects of delta-sarcoglycan Benign: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 and internal cut-off values, a variant classified as likely benign is not then subjected to further curation. The score for this variant resulted in a classification of likely benign for this disease. -
Limb-girdle muscular dystrophy, recessive Benign:1
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Primary dilated cardiomyopathy Benign:1
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Hypertrophic cardiomyopathy 1 Benign:1
The SGCD Gln283Arg variant is present at high frequency in the Exome Aggregation Consortium dataset and is particularly common in the East Asian population; allele frequency=0.006379 (MAF= 0.0004690, http://exac.broadinstitute.org/). We identified SGCD Gln283Arg in 1 HCM proband with no family history of HCM or SCD. Computational tools PolyPhen-2 and MutationTaster predict the amino acid substitution to be "probably damaging" and "disease-causing" respectively, however SIFT predicts this variant to be "tolerated". In summary, based on the current literature, our limited understanding of the role of SGCD in HCM, and an allele frequency higher than expected for HCM, we classify SGCD Gln283Arg as "likely benign". -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at