rs779204655
Variant summary
Our verdict is Pathogenic. Variant got 14 ACMG points: 14P and 0B. PVS1_StrongPM2PP5_Very_Strong
The NM_003124.5(SPR):c.655C>T(p.Arg219*) variant causes a stop gained change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000112 in 1,614,114 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_003124.5 stop_gained
Scores
Clinical Significance
Conservation
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ACMG classification
Verdict is Pathogenic. Variant got 14 ACMG points.
Transcripts
RefSeq
Ensembl
Frequencies
GnomAD3 genomes AF: 0.0000197 AC: 3AN: 152104Hom.: 0 Cov.: 33
GnomAD3 exomes AF: 0.0000318 AC: 8AN: 251456Hom.: 0 AF XY: 0.0000294 AC XY: 4AN XY: 135914
GnomAD4 exome AF: 0.0000103 AC: 15AN: 1461892Hom.: 0 Cov.: 31 AF XY: 0.0000124 AC XY: 9AN XY: 727246
GnomAD4 genome AF: 0.0000197 AC: 3AN: 152222Hom.: 0 Cov.: 33 AF XY: 0.0000269 AC XY: 2AN XY: 74420
ClinVar
Submissions by phenotype
Dopa-responsive dystonia due to sepiapterin reductase deficiency Pathogenic:5
The variant is observed at an extremely low frequency in the gnomAD v2.1.1 dataset (total allele frequency: 0.003%). Predicted Consequence/Location: Stop-gained (nonsense): predicted to result in a loss or disruption of normal protein function through protein truncation. The predicted truncated protein may be shortened by more than 10%. The variant has been reported at least twice as pathogenic with clinical assertions and evidence for the classification (ClinVar ID: VCV000235551 /PMID: 22291068). Therefore, this variant is classified as Pathogenic according to the recommendation of ACMG/AMP guideline. -
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A heterozygous nonsense variant, NM_003124.4(SPR):c.655C>T, has been identified in exon 3 of 3 of the SPR gene. The variant is predicted to result in a premature stop codon at position 219 of the protein (NP_003115.1(SPR):p.Arg219*). This variant is predicted to result in loss of protein function through truncation (although no known functional domains are affected), which is a reported mechanism of pathogenicity for this gene. The variant is present in the gnomAD database at a frequency of 0.0032% (9 heterozygotes, 0 homozygotes). The variant has been previously described as pathogenic in several patients with dystonia (ClinVar, Friedman, J., et al. (2012), Dill, P., et al. (2012), Reale, C., et al. (2018)). Several variants also resulting in a premature termination codon have also been reported in multiple patients with dystonia (ClinVar, Friedman, J., et al. (2012)). Based on the information available at the time of curation, this variant has been classified as PATHOGENIC. -
Variant summary: SPR c.655C>T (p.Arg219X) results in a premature termination codon, predicted to cause a truncation of the encoded protein or absence of the protein. The variant allele was found at a frequency of 3.2e-05 in 251456 control chromosomes. c.655C>T has been reported in the literature in individuals affected with Multiple malformation syndromes (example: Kritioti_2021). These data indicate that the variant is likely to be associated with disease.The following publication has been ascertained in the context of this evaluation (PMID: 34324503). ClinVar contains an entry for this variant (Variation ID: 235551). Based on the evidence outlined above, the variant was classified as pathogenic. -
not provided Pathogenic:2
Nonsense variant predicted to result in protein truncation, as the last 43 amino acids are lost, and other loss-of-function variants have been reported downstream in HGMD; Not observed at significant frequency in large population cohorts (gnomAD); This variant is associated with the following publications: (PMID: 31980526, 31589614, 22291068, 34324503) -
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Dystonic disorder Pathogenic:1
For these reasons, this variant has been classified as Pathogenic. This variant disrupts a region of the SPR protein in which other variant(s) (p.Lys251*) have been determined to be pathogenic (PMID: 16917893, 18502672, 21431957, 21677200, 24212389, 25763508, 29116116). This suggests that this is a clinically significant region of the protein, and that variants that disrupt it are likely to be disease-causing. ClinVar contains an entry for this variant (Variation ID: 235551). This premature translational stop signal has been observed in individual(s) with sepiapterin reductase deficiency and/or SPR-related conditions (PMID: 22291068, 34324503). It has also been observed to segregate with disease in related individuals. This variant is present in population databases (rs779204655, gnomAD 0.01%). This sequence change creates a premature translational stop signal (p.Arg219*) in the SPR gene. While this is not anticipated to result in nonsense mediated decay, it is expected to disrupt the last 43 amino acid(s) of the SPR protein. -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at