20-45898068-T-G
Variant summary
Our verdict is Pathogenic. The variant received 14 ACMG points: 14P and 0B. PM2PP3_StrongPP5_Very_Strong
The NM_000308.4(CTSA):c.1318T>G(p.Phe440Val) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000496 in 1,613,876 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 (★★). Synonymous variant affecting the same amino acid position (i.e. F440F) has been classified as Likely benign.
Frequency
Consequence
NM_000308.4 missense
Scores
Clinical Significance
Conservation
Publications
- galactosialidosisInheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: G2P, Labcorp Genetics (formerly Invitae), Genomics England PanelApp, Orphanet, ClinGen, Illumina
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ACMG classification
Our verdict: Pathogenic. The variant received 14 ACMG points.
Variant Effect in Transcripts
ACMG analysis was done for transcript: NM_000308.4. You can select a different transcript below to see updated ACMG assignments.
RefSeq Transcripts
| Selected | Gene | Transcript | Tags | HGVSc | HGVSp | Effect | Exon Rank | Protein | UniProt |
|---|---|---|---|---|---|---|---|---|---|
| CTSA | NM_000308.4 | MANE Select | c.1318T>G | p.Phe440Val | missense | Exon 14 of 15 | NP_000299.3 | ||
| CTSA | NM_001127695.3 | c.1318T>G | p.Phe440Val | missense | Exon 14 of 15 | NP_001121167.1 | |||
| CTSA | NM_001167594.3 | c.1267T>G | p.Phe423Val | missense | Exon 13 of 14 | NP_001161066.2 |
Ensembl Transcripts
| Selected | Gene | Transcript | Tags | HGVSc | HGVSp | Effect | Exon Rank | Protein | UniProt |
|---|---|---|---|---|---|---|---|---|---|
| CTSA | ENST00000646241.3 | MANE Select | c.1318T>G | p.Phe440Val | missense | Exon 14 of 15 | ENSP00000493613.2 | ||
| CTSA | ENST00000372484.8 | TSL:1 | c.1372T>G | p.Phe458Val | missense | Exon 14 of 15 | ENSP00000361562.3 | ||
| CTSA | ENST00000191018.9 | TSL:1 | c.1318T>G | p.Phe440Val | missense | Exon 14 of 15 | ENSP00000191018.5 |
Frequencies
GnomAD3 genomes AF: 0.0000197 AC: 3AN: 151994Hom.: 0 Cov.: 32 show subpopulations
GnomAD2 exomes AF: 0.00000795 AC: 2AN: 251430 AF XY: 0.0000147 show subpopulations
GnomAD4 exome AF: 0.00000342 AC: 5AN: 1461882Hom.: 0 Cov.: 31 AF XY: 0.00000550 AC XY: 4AN XY: 727246 show subpopulations
GnomAD4 genome AF: 0.0000197 AC: 3AN: 151994Hom.: 0 Cov.: 32 AF XY: 0.0000269 AC XY: 2AN XY: 74216 show subpopulations
ClinVar
Submissions by phenotype
Combined deficiency of sialidase AND beta galactosidase Pathogenic:2
Variant summary: CTSA c.1318T>G (p.Phe440Val) results in a non-conservative amino acid change in 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 8e-06 in 251430 control chromosomes (gnomAD). c.1318T>G has been reported in the literature in individuals affected with Galactosialidosis (examples: Zhou_1991, Zhou_1996). These data indicate that the variant may be associated with disease. At least one publication reports experimental evidence that this missense change affects CTSA function (Zhou_1991). The following publications have been ascertained in the context of this evaluation (PMID: 1756715, 8968752, 9435242). ClinVar contains an entry for this variant (Variation ID: 375). Based on the evidence outlined above, the variant was classified as likely pathogenic.
This sequence change replaces phenylalanine, which is neutral and non-polar, with valine, which is neutral and non-polar, at codon 458 of the CTSA protein (p.Phe458Val). This variant is present in population databases (rs137854540, gnomAD 0.004%). This missense change has been observed in individuals with galactosialidosis (PMID: 1756715, 8968752). This variant is also known as p.Phe412Val. ClinVar contains an entry for this variant (Variation ID: 375). 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 disruptive. Experimental studies have shown that this missense change affects CTSA function (PMID: 1756715). In summary, the currently available evidence indicates that the variant is pathogenic, but additional data are needed to prove that conclusively. Therefore, this variant has been classified as Likely Pathogenic.
GALACTOSIALIDOSIS, LATE INFANTILE Pathogenic:1
not provided Pathogenic:1
Published functional studies demonstrate a damaging effect (PMID: 1756715); Not observed at significant frequency in large population cohorts (gnomAD); Also known as p.(F412V); This variant is associated with the following publications: (PMID: 2148053, 9435242, 26659599, 20507906, 11212324, 1756715, 26147798, 28603679, 8968752, 23915561, 3149149)
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at