rs137854544
Variant summary
Our verdict is Pathogenic. Variant got 10 ACMG points: 10P and 0B. PM2PP5_Very_Strong
The NM_000308.4(CTSA):c.745T>A(p.Tyr249Asn) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000459 in 1,613,036 control chromosomes in the GnomAD database, with no homozygous occurrence. 12/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Pathogenic (★★).
Frequency
Consequence
NM_000308.4 missense
Scores
Clinical Significance
Conservation
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ACMG classification
Verdict is Pathogenic. Variant got 10 ACMG points.
Transcripts
RefSeq
Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | MANE | Protein | UniProt |
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CTSA | NM_000308.4 | c.745T>A | p.Tyr249Asn | missense_variant | Exon 8 of 15 | ENST00000646241.3 | NP_000299.3 | |
CTSA | NM_001127695.3 | c.745T>A | p.Tyr249Asn | missense_variant | Exon 8 of 15 | NP_001121167.1 | ||
CTSA | NM_001167594.3 | c.694T>A | p.Tyr232Asn | missense_variant | Exon 7 of 14 | NP_001161066.2 | ||
CTSA | NR_133656.2 | n.797T>A | non_coding_transcript_exon_variant | Exon 8 of 15 |
Ensembl
Frequencies
GnomAD3 genomes AF: 0.0000591 AC: 9AN: 152220Hom.: 0 Cov.: 33
GnomAD3 exomes AF: 0.0000358 AC: 9AN: 251316Hom.: 0 AF XY: 0.0000442 AC XY: 6AN XY: 135862
GnomAD4 exome AF: 0.0000445 AC: 65AN: 1460816Hom.: 0 Cov.: 31 AF XY: 0.0000427 AC XY: 31AN XY: 726796
GnomAD4 genome AF: 0.0000591 AC: 9AN: 152220Hom.: 0 Cov.: 33 AF XY: 0.0000538 AC XY: 4AN XY: 74370
ClinVar
Submissions by phenotype
Combined deficiency of sialidase AND beta galactosidase Pathogenic:5
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This sequence change replaces tyrosine, which is neutral and polar, with asparagine, which is neutral and polar, at codon 267 of the CTSA protein (p.Tyr267Asn). This variant is present in population databases (rs137854544, gnomAD 0.008%). This missense change has been observed in individual(s) with galactosialidosis (PMID: 8514852, 8968752, 22386972, 24769197; 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: 381). An algorithm developed to predict the effect of missense changes on protein structure and function (PolyPhen-2) suggests that this variant is likely to be tolerated. Experimental studies have shown that this missense change affects CTSA function (PMID: 8514852, 8968752, 10333491, 10944848). For these reasons, this variant has been classified as Pathogenic. -
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Variant summary: CTSA c.745T>A (p.Tyr249Asn) results in a non-conservative amino acid change in the encoded protein sequence. Three of five in-silico tools predict a benign effect of the variant on protein function. The variant allele was found at a frequency of 3.6e-05 in 251316 control chromosomes (gnomAD). c.745T>A has been reported in the literature in multiple individuals affected with Galactosialidosis (Zhou_1996, Shimmoto_1993, Lehman_2012, Prada_2014), and some were reported as compound heterozygous with other pathogenic variants. These data indicate that the variant is very likely to be associated with disease. Several publications report experimental evidence evaluating an impact on protein function, finding disruption in lysosomal compartmentalization, substantially reduced cathepsin A activity, and more modest reductions in beta-galactosidase and alpha-neuraminidase activity (Zhou_1996, Shimmoto_1993, Takiguchi_2000). The following publications have been ascertained in the context of this evaluation (PMID: 8968752, 8514852, 22386972, 10944848, 24769197). Two submitters have cited clinical-significance assessments for this variant to ClinVar after 2014, and classified the variant as pathogenic. Based on the evidence outlined above, the variant was classified as pathogenic. -
Galactosialidosis, late infantile Pathogenic:1
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Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at