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

Genomes: 𝑓 0.000020 ( 0 hom., cov: 33)
Exomes 𝑓: 0.000010 ( 0 hom. )

Consequence

SPR
NM_003124.5 stop_gained

Scores

2
2
3

Clinical Significance

Pathogenic criteria provided, multiple submitters, no conflicts P:8

Conservation

PhyloP100: 1.27
Variant links:
Genes affected
SPR (HGNC:11257): (sepiapterin reductase) This gene encodes an aldo-keto reductase that catalyzes the NADPH-dependent reduction of pteridine derivatives and is important in the biosynthesis of tetrahydrobiopterin (BH4). Mutations in this gene result in DOPA-responsive dystonia due to sepiaterin reductase deficiency. A pseudogene has been identified on chromosome 1. [provided by RefSeq, Jul 2008]

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Pathogenic. Variant got 14 ACMG points.

PVS1
Loss of function variant, product does not undergo nonsense mediated mRNA decay. Variant is located in the 3'-most exon, not predicted to undergo nonsense mediated mRNA decay. Fraction of 0.167 CDS is truncated, and there are 2 pathogenic variants in the truncated region.
PM2
Very rare variant in population databases, with high coverage;
PP5
Variant 2-72891406-C-T is Pathogenic according to our data. Variant chr2-72891406-C-T is described in ClinVar as [Pathogenic]. Clinvar id is 235551.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr2-72891406-C-T is described in Lovd as [Pathogenic]. Variant chr2-72891406-C-T is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
SPRNM_003124.5 linkc.655C>T p.Arg219* stop_gained Exon 3 of 3 ENST00000234454.6 NP_003115.1 P35270

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
SPRENST00000234454.6 linkc.655C>T p.Arg219* stop_gained Exon 3 of 3 1 NM_003124.5 ENSP00000234454.5 P35270
SPRENST00000498749.1 linkn.600C>T non_coding_transcript_exon_variant Exon 3 of 3 3 ENSP00000519026.1

Frequencies

GnomAD3 genomes
AF:
0.0000197
AC:
3
AN:
152104
Hom.:
0
Cov.:
33
show subpopulations
Gnomad AFR
AF:
0.00
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.00
Gnomad ASJ
AF:
0.00
Gnomad EAS
AF:
0.00
Gnomad SAS
AF:
0.000208
Gnomad FIN
AF:
0.0000944
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.0000147
Gnomad OTH
AF:
0.00
GnomAD3 exomes
AF:
0.0000318
AC:
8
AN:
251456
Hom.:
0
AF XY:
0.0000294
AC XY:
4
AN XY:
135914
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.0000578
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad SAS exome
AF:
0.0000327
Gnomad FIN exome
AF:
0.0000924
Gnomad NFE exome
AF:
0.0000264
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000103
AC:
15
AN:
1461892
Hom.:
0
Cov.:
31
AF XY:
0.0000124
AC XY:
9
AN XY:
727246
show subpopulations
Gnomad4 AFR exome
AF:
0.00
Gnomad4 AMR exome
AF:
0.0000671
Gnomad4 ASJ exome
AF:
0.00
Gnomad4 EAS exome
AF:
0.00
Gnomad4 SAS exome
AF:
0.0000116
Gnomad4 FIN exome
AF:
0.0000374
Gnomad4 NFE exome
AF:
0.00000540
Gnomad4 OTH exome
AF:
0.00
GnomAD4 genome
AF:
0.0000197
AC:
3
AN:
152222
Hom.:
0
Cov.:
33
AF XY:
0.0000269
AC XY:
2
AN XY:
74420
show subpopulations
Gnomad4 AFR
AF:
0.00
Gnomad4 AMR
AF:
0.00
Gnomad4 ASJ
AF:
0.00
Gnomad4 EAS
AF:
0.00
Gnomad4 SAS
AF:
0.000208
Gnomad4 FIN
AF:
0.0000944
Gnomad4 NFE
AF:
0.0000147
Gnomad4 OTH
AF:
0.00
Bravo
AF:
0.0000113
ExAC
AF:
0.0000165
AC:
2

ClinVar

Significance: Pathogenic
Submissions summary: Pathogenic:8
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Dopa-responsive dystonia due to sepiapterin reductase deficiency Pathogenic:5
Aug 08, 2023
3billion
Significance: Pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing

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. -

Mar 05, 2018
Genomic Research Center, Shahid Beheshti University of Medical Sciences
Significance: Pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

Apr 10, 2020
Cytogenetics and Genomics Lab, Cyprus Institute Of Neurology and Genetics
Significance: Pathogenic
Review Status: criteria provided, single submitter
Collection Method: research

- -

Aug 28, 2019
Victorian Clinical Genetics Services, Murdoch Childrens Research Institute
Significance: Pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing

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. -

Oct 10, 2024
Women's Health and Genetics/Laboratory Corporation of America, LabCorp
Significance: Pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing

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
Jun 08, 2023
GeneDx
Significance: Pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing

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) -

May 18, 2016
Center for Pediatric Genomic Medicine, Children's Mercy Hospital and Clinics
Significance: Pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

Dystonic disorder Pathogenic:1
Jun 09, 2023
Labcorp Genetics (formerly Invitae), Labcorp
Significance: Pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing

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: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
BayesDel_addAF
Pathogenic
0.50
D
BayesDel_noAF
Pathogenic
0.28
CADD
Pathogenic
34
DANN
Uncertain
0.98
Eigen
Uncertain
0.31
Eigen_PC
Benign
0.0068
FATHMM_MKL
Benign
0.67
D
Vest4
0.91
GERP RS
0.58

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.0
Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

LitVar

Below is the list of publications found by LitVar. It may be empty.

Other links and lift over

dbSNP: rs779204655; hg19: chr2-73118535; COSMIC: COSV52297859; API