rs398123429
Variant summary
Our verdict is Pathogenic. The variant received 16 ACMG points: 16P and 0B. PM1PM2PP3_StrongPP5_Very_Strong
The NM_000512.5(GALNS):c.1171A>G(p.Met391Val) variant causes a missense change. The variant allele was found at a frequency of 0.000013 in 1,613,224 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
Publications
- mucopolysaccharidosis type 4AInheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: G2P, ClinGen, Labcorp Genetics (formerly Invitae), Orphanet, Genomics England PanelApp
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ACMG classification
Our verdict: Pathogenic. The variant received 16 ACMG points.
Transcripts
RefSeq
Ensembl
Frequencies
GnomAD3 genomes AF: 0.0000197 AC: 3AN: 152164Hom.: 0 Cov.: 33 show subpopulations
GnomAD2 exomes AF: 0.00000801 AC: 2AN: 249748 AF XY: 0.00 show subpopulations
GnomAD4 exome AF: 0.0000123 AC: 18AN: 1461060Hom.: 0 Cov.: 32 AF XY: 0.0000151 AC XY: 11AN XY: 726808 show subpopulations
Age Distribution
GnomAD4 genome AF: 0.0000197 AC: 3AN: 152164Hom.: 0 Cov.: 33 AF XY: 0.0000404 AC XY: 3AN XY: 74306 show subpopulations
Age Distribution
ClinVar
Submissions by phenotype
Mucopolysaccharidosis, MPS-IV-A Pathogenic:4
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This sequence change replaces methionine, which is neutral and non-polar, with valine, which is neutral and non-polar, at codon 391 of the GALNS protein (p.Met391Val). This variant is present in population databases (rs398123429, gnomAD 0.002%). This missense change has been observed in individual(s) with mucopolysaccharidosis IVA (PMID: 7668283, 9375852, 25137622). ClinVar contains an entry for this variant (Variation ID: 93162). 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 GALNS protein function with a positive predictive value of 95%. Experimental studies have shown that this missense change affects GALNS function (PMID: 9375852). For these reasons, this variant has been classified as Pathogenic. -
In vitro and in vivo functional studies supportive of a damaging effect on the gene product (low to null in vitro enzymatic activity; low to null enzymatic activity in homozygotes; 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) -
Morquio syndrome Pathogenic:1
Variant summary: GALNS c.1171A>G (p.Met391Val) results in a conservative amino acid change in the encoded protein sequence. Four of five in-silico tools predict a benign effect of the variant on protein function. The variant allele was found at a frequency of 8e-06 in 249748 control chromosomes. c.1171A>G has been reported in the literature in multiple individuals affected with Mucopolysaccharidosis Type IVA (Morquio Syndrome A) (example, Tomatsu_1995, Morrone_2014, Dung_2014). These data indicate that the variant is very likely to be associated with disease. At least one publication reports experimental evidence evaluating an impact on protein function. The most pronounced variant effect results in <10% of normal activity in a transient expression system (Tomatsu_1995). No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014 although one submitter has classified the variant as pathogenic before 2014. 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