rs746756997
Variant summary
Our verdict is Pathogenic. Variant got 16 ACMG points: 16P and 0B. PM1PM2PP3_StrongPP5_Very_Strong
The NM_000512.5(GALNS):c.953T>G(p.Met318Arg) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000031 in 1,613,754 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 (★★).
Frequency
Consequence
NM_000512.5 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: 0.0000132 AC: 2AN: 152076Hom.: 0 Cov.: 32
GnomAD3 exomes AF: 0.0000199 AC: 5AN: 250646Hom.: 0 AF XY: 0.00000737 AC XY: 1AN XY: 135668
GnomAD4 exome AF: 0.00000205 AC: 3AN: 1461678Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0AN XY: 727138
GnomAD4 genome AF: 0.0000132 AC: 2AN: 152076Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0AN XY: 74268
ClinVar
Submissions by phenotype
Mucopolysaccharidosis, MPS-IV-A Pathogenic:5
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This sequence change replaces methionine, which is neutral and non-polar, with arginine, which is basic and polar, at codon 318 of the GALNS protein (p.Met318Arg). This variant is present in population databases (rs746756997, gnomAD 0.04%). This missense change has been observed in individual(s) with mucopolysaccharidosis type IVA (PMID: 23876334, 24035930, 30458289). ClinVar contains an entry for this variant (Variation ID: 199031). Invitae Evidence Modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) indicates that this missense variant is expected to disrupt GALNS protein function with a positive predictive value of 95%. For these reasons, this variant has been classified as Pathogenic. -
PM2_Supporting+PP3_Strong+PM3_VeryStrong+PP4 -
In vitro and in vivo functional studies supportive of a damaging effect on the gene product (low to null enzymatic activity in homozygotes; low to null in vitro enzymatic activity; PS3_strong); the prevalence of the variant in affected individuals is significantly increased compared with the prevalence in controls (PS4_strong); very low frequency in gnomAD v2.1.1 (PM2_moderate); multiple lines of computational evidence support a deleterious effect on the gene (PP3_supporting) -
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Inborn genetic diseases Pathogenic:1
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Morquio syndrome Pathogenic:1
Variant summary: GALNS c.953T>G (p.Met318Arg) results in a non-conservative amino acid change located in the Sulfatase, N-terminal domain 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 2e-05 in 250646 control chromosomes (gnomAD). The variant, c.953T>G, has been reported in the literature in multiple individuals affected with Mucopolysaccharidosis Type IVA (Morquio Syndrome A) (Ogawa_1995, Morrone_2014, Xie_2019). These data indicate that the variant is very likely to be associated with disease. One publication, Ogawa_1995, showed that transfected GALNS activity of this variant was <10% of normal activity. A ClinVar submission from a clinical diagnostic laboratory (evaluation after 2014) cites the variant as uncertain significance. Based on the evidence outlined above, the variant was classified as pathogenic. -
not provided Pathogenic:1
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Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at