rs150078285

Variant summary

Our verdict is Uncertain significance. The variant received 1 ACMG points: 3P and 2B. PM1PP2BP4_Moderate

The NM_003124.5(SPR):​c.654G>A​(p.Met218Ile) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00026 in 1,614,084 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 16/22 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★).

Frequency

Genomes: 𝑓 0.00013 ( 0 hom., cov: 33)
Exomes 𝑓: 0.00027 ( 0 hom. )

Consequence

SPR
NM_003124.5 missense

Scores

1
17

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:4

Conservation

PhyloP100: -0.00100

Publications

2 publications found
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]
SPR Gene-Disease associations (from GenCC):
  • dopa-responsive dystonia due to sepiapterin reductase deficiency
    Inheritance: AD, AR Classification: DEFINITIVE, STRONG, MODERATE, SUPPORTIVE Submitted by: Genomics England PanelApp, Orphanet, ClinGen, G2P, Ambry Genetics
  • BH4-deficient hyperphenylalaninemia A
    Inheritance: AR Classification: STRONG Submitted by: Labcorp Genetics (formerly Invitae)

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Uncertain_significance. The variant received 1 ACMG points.

PM1
In a chain Sepiapterin reductase (size 260) in uniprot entity SPRE_HUMAN there are 9 pathogenic changes around while only 2 benign (82%) in NM_003124.5
PP2
Missense variant in the gene, where a lot of missense mutations are associated with disease in ClinVar. The gene has 6 curated pathogenic missense variants (we use a threshold of 10). The gene has 1 curated benign missense variants. Gene score misZ: 0.7325 (below the threshold of 3.09). Trascript score misZ: -0.70614 (below the threshold of 3.09). GenCC associations: The gene is linked to dopa-responsive dystonia due to sepiapterin reductase deficiency, BH4-deficient hyperphenylalaninemia A.
BP4
Computational evidence support a benign effect (MetaRNN=0.07642409).

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
SPRNM_003124.5 linkc.654G>A p.Met218Ile missense_variant Exon 3 of 3 ENST00000234454.6 NP_003115.1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
SPRENST00000234454.6 linkc.654G>A p.Met218Ile missense_variant Exon 3 of 3 1 NM_003124.5 ENSP00000234454.5
SPRENST00000713723.1 linkc.363G>A p.Met121Ile missense_variant Exon 2 of 2 ENSP00000519027.1
SPRENST00000498749.2 linkn.*236G>A non_coding_transcript_exon_variant Exon 3 of 3 3 ENSP00000519026.1
SPRENST00000498749.2 linkn.*236G>A 3_prime_UTR_variant Exon 3 of 3 3 ENSP00000519026.1

Frequencies

GnomAD3 genomes
AF:
0.000131
AC:
20
AN:
152190
Hom.:
0
Cov.:
33
show subpopulations
Gnomad AFR
AF:
0.0000724
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.00
Gnomad ASJ
AF:
0.00
Gnomad EAS
AF:
0.00
Gnomad SAS
AF:
0.00
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.000250
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.0000954
AC:
24
AN:
251462
AF XY:
0.0000883
show subpopulations
Gnomad AFR exome
AF:
0.0000615
Gnomad AMR exome
AF:
0.0000289
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.000176
Gnomad OTH exome
AF:
0.000326
GnomAD4 exome
AF:
0.000273
AC:
399
AN:
1461894
Hom.:
0
Cov.:
31
AF XY:
0.000260
AC XY:
189
AN XY:
727248
show subpopulations
African (AFR)
AF:
0.0000299
AC:
1
AN:
33480
American (AMR)
AF:
0.0000671
AC:
3
AN:
44724
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26136
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39700
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86258
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53420
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
0.000336
AC:
374
AN:
1112012
Other (OTH)
AF:
0.000348
AC:
21
AN:
60396
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.472
Heterozygous variant carriers
0
27
55
82
110
137
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
20
40
60
80
100
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
GnomAD4 genome
AF:
0.000131
AC:
20
AN:
152190
Hom.:
0
Cov.:
33
AF XY:
0.000108
AC XY:
8
AN XY:
74340
show subpopulations
African (AFR)
AF:
0.0000724
AC:
3
AN:
41452
American (AMR)
AF:
0.00
AC:
0
AN:
15280
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3470
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5200
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4824
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10606
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.000250
AC:
17
AN:
68038
Other (OTH)
AF:
0.00
AC:
0
AN:
2092
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.540
Heterozygous variant carriers
0
2
3
5
6
8
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Genome Het
Variant carriers
0
2
4
6
8
10
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
Alfa
AF:
0.000210
Hom.:
0
Bravo
AF:
0.000125
TwinsUK
AF:
0.000270
AC:
1
ALSPAC
AF:
0.000778
AC:
3
ESP6500AA
AF:
0.000227
AC:
1
ESP6500EA
AF:
0.000349
AC:
3
ExAC
AF:
0.0000988
AC:
12
EpiCase
AF:
0.000273
EpiControl
AF:
0.000237

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:4
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Dopa-responsive dystonia due to sepiapterin reductase deficiency Uncertain:2
Sep 01, 2021
Fulgent Genetics, Fulgent Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

May 06, 2020
Department of Pathology and Laboratory Medicine, Sinai Health System
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:research

Inborn genetic diseases Uncertain:1
Sep 17, 2021
Ambry Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The c.654G>A (p.M218I) alteration is located in exon 3 (coding exon 3) of the SPR gene. This alteration results from a G to A substitution at nucleotide position 654, causing the methionine (M) at amino acid position 218 to be replaced by an isoleucine (I). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear.

Dystonic disorder Uncertain:1
Jul 31, 2022
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces methionine, which is neutral and non-polar, with isoleucine, which is neutral and non-polar, at codon 218 of the SPR protein (p.Met218Ile). This variant is present in population databases (rs150078285, gnomAD 0.02%). This variant has not been reported in the literature in individuals affected with SPR-related conditions. ClinVar contains an entry for this variant (Variation ID: 574213). Algorithms developed to predict the effect of missense changes on protein structure and function (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be tolerated. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance.

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Uncertain
0.40
BayesDel_addAF
Benign
-0.34
T
BayesDel_noAF
Benign
-0.46
CADD
Benign
3.3
DANN
Benign
0.82
DEOGEN2
Benign
0.18
T
Eigen
Benign
-0.99
Eigen_PC
Benign
-0.95
FATHMM_MKL
Benign
0.42
N
LIST_S2
Benign
0.50
T
M_CAP
Benign
0.069
D
MetaRNN
Benign
0.076
T
MetaSVM
Benign
-0.73
T
MutationAssessor
Benign
-0.10
N
PhyloP100
-0.0010
PrimateAI
Benign
0.31
T
PROVEAN
Benign
0.11
N
REVEL
Benign
0.20
Sift
Benign
0.31
T
Sift4G
Benign
0.41
T
Vest4
0.042
ClinPred
0.022
T
GERP RS
-2.0
Varity_R
0.13
gMVP
0.41
Mutation Taster
=95/5
polymorphism

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

Other links and lift over

dbSNP: rs150078285; hg19: chr2-73118534; COSMIC: COSV105093278; API