rs587779408
Variant summary
Our verdict is Pathogenic. Variant got 16 ACMG points: 16P and 0B. PM1PM2PP3_StrongPP5_Very_Strong
The NM_000543.5(SMPD1):c.739G>A(p.Gly247Ser) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000236 in 1,612,708 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 Likely pathogenic (★★).
Frequency
Consequence
NM_000543.5 missense
Scores
Clinical Significance
Conservation
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ACMG classification
Verdict is Pathogenic. Variant got 16 ACMG points.
Transcripts
RefSeq
Ensembl
Frequencies
GnomAD3 genomes AF: 0.0000263 AC: 4AN: 152248Hom.: 0 Cov.: 31
GnomAD3 exomes AF: 0.0000241 AC: 6AN: 248600Hom.: 0 AF XY: 0.0000371 AC XY: 5AN XY: 134880
GnomAD4 exome AF: 0.0000233 AC: 34AN: 1460460Hom.: 0 Cov.: 37 AF XY: 0.0000234 AC XY: 17AN XY: 726624
GnomAD4 genome AF: 0.0000263 AC: 4AN: 152248Hom.: 0 Cov.: 31 AF XY: 0.0000538 AC XY: 4AN XY: 74388
ClinVar
Submissions by phenotype
Sphingomyelin/cholesterol lipidosis Pathogenic:3
Variant summary: SMPD1 c.739G>A (p.Gly247Ser) results in a non-conservative amino acid change located in the apaH type Calcineurin-like phosphoesterase domain (IPR004843) of the encoded protein sequence. Five of five in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 2.4e-05 in 248600 control chromosomes (gnomAD). The variant, c.739G>A (aka c.733G>A (p.G245S)) has been reported in the literature in multiple homozygous and compound heterozygous individuals affected with Niemann-Pick Disease (e.g. Simonaro_2002, Pittis_2004, Ricci_2004, Irun_2013). These data indicate that the variant is very likely to be associated with disease. Publications also reported experimental evidence evaluating an impact on protein function, demonstrating a severely decreased residual enzyme activity (i.e. less than 10%) in patient derived fibroblasts and leukocytes (Pittis_2004, Irun_2013). Seven clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014, and all of them classified the variant as pathogenic/likely pathogenic. Based on the evidence outlined above, the variant was classified as pathogenic. -
The p.Gly247Ser variant in SMPD1 (also known as p.Gly245Ser due to a difference in cDNA numbering) has been reported in at least 12 individuals with Niemann-Pick disease (PMID: 15234149, 12369017, 23252888, 24767253, 15221801, 19405096, 15241805) and has been identified in 0.004% (5/112836) of European (non-Finnish) chromosomes and 0.003% (1/34526) of Latino chromosomes by the Genome Aggregation Database (gnomAD, http://gnomad.broadinstitute.org; dbSNP rs587779408). Although this variant has been seen in the general population, its frequency is low enough to be consistent with a recessive carrier frequency. The presence of this variant in the homozygous state and in combination with reported pathogenic variants in individuals with Niemann-Pick disease increases the likelihood that the p.Arg247Ser variant is pathogenic (PMID: 15234149, 12369017, 23252888, 24767253, 15221801, 19405096, 15241805). The phenotype of individuals compound heterozygous for this variant is highly specific for Niemann-Pick based on acid sphingomyelinase activity in leukocytes or fibroblasts being <10%, consistent with disease (PMID: 23252888, 15241805). In summary, this variant meets criteria to be classified as pathogenic for Niemann-Pick disease in an autosomal recessive manner based on multiple occurrences in the homozygous state and with pathogenic SMPD1 variants in affected individuals and low frequency in the general population. ACMG/AMP Criteria applied: PM3_very-strong, PM2, PP4 (Richards 2015). -
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not provided Pathogenic:3
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Also known as G245S using alternate nomenclature; In one cohort of 15 patients with type A or B Niemann-Pick disease, G247S accounted for 12% of the pathogenic variants identified (Irun et al., 2013); Not observed at a significant frequency in large population cohorts (Lek et al., 2016); The majority of missense variants in this gene are considered pathogenic (Stenson et al., 2014); In silico analysis, which includes protein predictors and evolutionary conservation, supports a deleterious effect This variant is associated with the following publications: (PMID: 31980526, 30223864, 23430884, 19405096, 23252888, 15241805, 24767253, 15221801, 15234149, 12369017, 30985853) -
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Niemann-Pick disease, type A Pathogenic:2
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Ceroid lipofuscinosis, neuronal, 6A Pathogenic:1
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Niemann-Pick disease, type A;C0268243:Niemann-Pick disease, type B Pathogenic:1
This sequence change replaces glycine, which is neutral and non-polar, with serine, which is neutral and polar, at codon 247 of the SMPD1 protein (p.Gly247Ser). This variant is present in population databases (rs587779408, gnomAD 0.007%). This missense change has been observed in individuals with Niemann-Pick disease (PMID: 12369017, 15221801, 15234149, 15241805, 23252888, 24767253). This variant is also known as p.Gly245Ser. ClinVar contains an entry for this variant (Variation ID: 100731). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is expected to disrupt SMPD1 protein function with a positive predictive value of 95%. Experimental studies have shown that this missense change affects SMPD1 function (PMID: 15241805). This variant disrupts the p.Gly247 amino acid residue in SMPD1. Other variant(s) that disrupt this residue have been observed in individuals with SMPD1-related conditions (PMID: 23430884), which suggests that this may be a clinically significant amino acid residue. For these reasons, this variant has been classified as Pathogenic. -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at