rs778336949
Variant summary
Our verdict is Pathogenic. Variant got 15 ACMG points: 15P and 0B. PM1PM2PM5PP3PP5_Very_Strong
The NM_000199.5(SGSH):c.221G>A(p.Arg74His) variant causes a missense change. The variant allele was found at a frequency of 0.0000044 in 1,590,362 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 (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R74L) has been classified as Pathogenic.
Frequency
Consequence
NM_000199.5 missense
Scores
Clinical Significance
Conservation
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ACMG classification
Verdict is Pathogenic. Variant got 15 ACMG points.
Transcripts
RefSeq
Gene | Transcript | HGVSc | HGVSp | Effect | #exon/exons | MANE | UniProt |
---|---|---|---|---|---|---|---|
SGSH | NM_000199.5 | c.221G>A | p.Arg74His | missense_variant | 2/8 | ENST00000326317.11 |
Ensembl
Gene | Transcript | HGVSc | HGVSp | Effect | #exon/exons | TSL | MANE | Appris | UniProt |
---|---|---|---|---|---|---|---|---|---|
SGSH | ENST00000326317.11 | c.221G>A | p.Arg74His | missense_variant | 2/8 | 1 | NM_000199.5 | P1 |
Frequencies
GnomAD3 genomes ? AF: 0.00000657 AC: 1AN: 152252Hom.: 0 Cov.: 33
GnomAD4 exome AF: 0.00000417 AC: 6AN: 1437992Hom.: 0 Cov.: 31 AF XY: 0.00000420 AC XY: 3AN XY: 713484
GnomAD4 genome ? AF: 0.00000656 AC: 1AN: 152370Hom.: 0 Cov.: 33 AF XY: 0.0000134 AC XY: 1AN XY: 74500
ClinVar
Submissions by phenotype
Mucopolysaccharidosis, MPS-III-A Pathogenic:6
Likely pathogenic, criteria provided, single submitter | literature only | Laboratory of Diagnosis and Therapy of Lysosomal Disorders, University of Padova | Jan 01, 2019 | PS3: Low in vitro enzymatic activity. PM2: Absent from GnomAD - |
Pathogenic, criteria provided, single submitter | clinical testing | Women's Health and Genetics/Laboratory Corporation of America, LabCorp | Aug 03, 2021 | Variant summary: SGSH c.221G>A (p.Arg74His) results in a non-conservative amino acid change located in the Sulfatase, N-terminal domain (IPR000917) 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 4.7e-06 in 211504 control chromosomes (gnomAD and publication data). c.221G>A has been reported in the literature in multiple individuals affected with Mucopolysaccharidosis Type IIIA (Sanfilippo Syndrome A), including at least two homozygotes (Bunge_1997, Chabas_2001, Montfort_2004). These data indicate that the variant is very likely to be associated with disease. At least one functional study reports this variant results in reducing sulfamidase activity compared to WT activity (Montfort_2004). Three ClinVar submitters (evaluation after 2014) cite the variant as pathogenic (n=1) and likely pathogenic (n=2). Based on the evidence outlined above, the variant was classified as pathogenic. - |
Pathogenic, criteria provided, single submitter | clinical testing | Baylor Genetics | Dec 17, 2023 | - - |
Likely pathogenic, criteria provided, single submitter | clinical testing | Counsyl | Jan 30, 2017 | - - |
Likely pathogenic, criteria provided, single submitter | clinical testing | Genome-Nilou Lab | Nov 07, 2021 | - - |
Pathogenic, criteria provided, single submitter | clinical testing | Invitae | Dec 19, 2023 | This sequence change replaces arginine, which is basic and polar, with histidine, which is basic and polar, at codon 74 of the SGSH protein (p.Arg74His). The frequency data for this variant in the population databases is considered unreliable, as metrics indicate poor data quality at this position in the gnomAD database. This missense change has been observed in individual(s) with MPS IIIA (PMID: 9401012, 11343308; Invitae). In at least one individual the data is consistent with being in trans (on the opposite chromosome) from a pathogenic variant. ClinVar contains an entry for this variant (Variation ID: 550504). 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 SGSH protein function with a positive predictive value of 95%. This variant disrupts the p.Arg74 amino acid residue in SGSH. Other variant(s) that disrupt this residue have been determined to be pathogenic (PMID: 9285796, 9401012, 11343308, 22976768, 28844463). This suggests that this residue is clinically significant, and that variants that disrupt this residue are likely to be disease-causing. 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