2-72888511-G-A

Position:

chr2-72888511-G-A

Variant summary

Our verdict is Uncertain significance. Variant got 0 ACMG points: 2P and 2B. PM2BP4_Moderate

The NM_003124.5(SPR):c.502G>A(p.Ala168Thr) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000213 in 1,612,404 control chromosomes in the GnomAD database, including 1 homozygotes. In-silico tool predicts a benign outcome for this variant. 15/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★).

Frequency

Genomes: 𝑓 0.00012 ( 0 hom., cov: 33)

Exomes 𝑓: 0.00022 ( 1 hom. )

Consequence

SPR
NM_003124.5 missense

Scores

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:2

Conservation

PhyloP100: 0.716

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 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Uncertain_significance. Variant got 0 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

BP4

Computational evidence support a benign effect (MetaRNN=0.20771691).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
SPR	NM_003124.5 linkuse as main transcript	c.502G>A	p.Ala168Thr	missense_variant	2/3	ENST00000234454.6	NP_003115.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
SPR	ENST00000234454.6 linkuse as main transcript	c.502G>A	p.Ala168Thr	missense_variant	2/3	1	NM_003124.5	ENSP00000234454	P1
SPR	ENST00000498749.1 linkuse as main transcript	n.447G>A		non_coding_transcript_exon_variant	2/3	3

Frequencies

GnomAD3 genomes

AF:

0.000118

AC:

AN:

152216

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000723

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:

0.000221

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.0000521

AC:

AN:

249622

Hom.:

AF XY:

0.0000593

AC XY:

AN XY:

134824

show subpopulations

Gnomad AFR exome

AF:

0.0000616

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.000101

Gnomad EAS exome

AF:

0.00

Gnomad SAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000974

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.000223

AC:

326

AN:

1460188

Hom.:

Cov.:

AF XY:

0.000202

AC XY:

147

AN XY:

726296

show subpopulations

Gnomad4 AFR exome

AF:

0.0000598

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.0000384

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.00

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.000285

Gnomad4 OTH exome

AF:

0.0000995

GnomAD4 genome

AF:

0.000118

AC:

AN:

152216

Hom.:

Cov.:

AF XY:

0.000108

AC XY:

AN XY:

74352

show subpopulations

Gnomad4 AFR

AF:

0.0000723

Gnomad4 AMR

AF:

0.00

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.000221

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.000148

Hom.:

Bravo

AF:

0.0000982

TwinsUK

AF:

0.000270

AC:

ALSPAC

AF:

0.000259

AC:

ESP6500AA

AF:

0.00

AC:

ESP6500EA

AF:

0.000233

AC:

ExAC

AF:

0.0000412

AC:

EpiCase

AF:

0.000164

EpiControl

AF:

0.00

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Inborn genetic diseases

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Nov 10, 2022

The c.502G>A (p.A168T) alteration is located in exon 2 (coding exon 2) of the SPR gene. This alteration results from a G to A substitution at nucleotide position 502, causing the alanine (A) at amino acid position 168 to be replaced by a threonine (T). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Dystonic disorder

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Sep 01, 2021

This sequence change replaces alanine with threonine at codon 168 of the SPR protein (p.Ala168Thr). The alanine residue is weakly conserved and there is a small physicochemical difference between alanine and threonine. This variant is present in population databases (rs145110113, ExAC 0.008%). This variant has not been reported in the literature in individuals affected with SPR-related conditions. Algorithms developed to predict the effect of missense changes on protein structure and function output the following: SIFT: "Tolerated"; PolyPhen-2: "Benign"; Align-GVGD: "Class C0". The threonine amino acid residue is found in multiple mammalian species, which suggests that this missense change does not adversely affect protein function. 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

Benign

0.17

BayesDel_addAF

Benign

-0.25

BayesDel_noAF

Benign

-0.40

CADD

Benign

DANN

Uncertain

1.0

DEOGEN2

Uncertain

0.50

Eigen

Benign

-0.50

Eigen_PC

Benign

-0.52

FATHMM_MKL

Benign

0.56

LIST_S2

Benign

0.77

M_CAP

Benign

0.036

MetaRNN

Benign

0.21

MetaSVM

Uncertain

-0.23

MutationAssessor

Benign

1.5

MutationTaster

Benign

0.90

PrimateAI

Benign

0.27

PROVEAN

Benign

-1.4

REVEL

Benign

0.25

Sift

Benign

0.061

Sift4G

Benign

0.20

Polyphen

0.28

Vest4

0.36

MVP

0.85

MPC

0.39

ClinPred

0.050

GERP RS

0.022

Varity_R

0.42

gMVP

0.74

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.11

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.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over