14-54859683-C-T

Position:

chr14-54859683-C-T

Variant summary

Our verdict is Benign. Variant got -10 ACMG points: 0P and 10B. BP4_StrongBP6BP7BS2

The NM_000161.3(GCH1):c.507G>A(p.Ala169=) variant causes a splice region, synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000635 in 1,576,860 control chromosomes in the GnomAD database, including 16 homozygotes. In-silico tool predicts a benign outcome for this variant. 3/3 splice prediction tools predict no significant impact on normal splicing. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Synonymous variant affecting the same amino acid position (i.e. A169A) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.00070 ( 0 hom., cov: 32)

Exomes 𝑓: 0.00063 ( 16 hom. )

Consequence

GCH1
NM_000161.3 splice_region, synonymous

Scores

Splicing: ADA: 0.00002066

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:2B:4

Conservation

PhyloP100: -3.24

Variant links:

Genes affected

GCH1 (HGNC:4193): (GTP cyclohydrolase 1) This gene encodes a member of the GTP cyclohydrolase family. The encoded protein is the first and rate-limiting enzyme in tetrahydrobiopterin (BH4) biosynthesis, catalyzing the conversion of GTP into 7,8-dihydroneopterin triphosphate. BH4 is an essential cofactor required by aromatic amino acid hydroxylases as well as nitric oxide synthases. Mutations in this gene are associated with malignant hyperphenylalaninemia and dopa-responsive dystonia. Several alternatively spliced transcript variants encoding different isoforms have been described; however, not all variants give rise to a functional enzyme. [provided by RefSeq, Jul 2008]

GCH1 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Benign. Variant got -10 ACMG points.

BP4

Computational evidence support a benign effect (BayesDel_noAF=-0.92).

BP6

Variant 14-54859683-C-T is Benign according to our data. Variant chr14-54859683-C-T is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 313395.We mark this variant Likely_benign, oryginal submissions are: {Benign=4, Uncertain_significance=2}.

BP7

Synonymous conserved (PhyloP=-3.24 with no splicing effect.

BS2

High Homozygotes in GnomAdExome4 at 16 SD gene

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
GCH1	NM_000161.3 linkuse as main transcript	c.507G>A	p.Ala169=	splice_region_variant, synonymous_variant	3/6	ENST00000491895.7

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
GCH1	ENST00000491895.7 linkuse as main transcript	c.507G>A	p.Ala169=	splice_region_variant, synonymous_variant	3/6	1	NM_000161.3	P1	P30793-1

Frequencies

GnomAD3 genomes

AF:

0.000703

AC:

107

AN:

152186

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000724

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.0000655

Gnomad ASJ

AF:

0.0259

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.000176

Gnomad OTH

AF:

0.000478

GnomAD3 exomes

AF:

0.00121

AC:

304

AN:

251240

Hom.:

AF XY:

0.00110

AC XY:

149

AN XY:

135774

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.0243

Gnomad EAS exome

AF:

0.00

Gnomad SAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.000423

Gnomad OTH exome

AF:

0.00179

GnomAD4 exome

AF:

0.000628

AC:

894

AN:

1424556

Hom.:

Cov.:

AF XY:

0.000622

AC XY:

442

AN XY:

711170

show subpopulations

Gnomad4 AFR exome

AF:

0.0000305

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.0252

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.00

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.000124

Gnomad4 OTH exome

AF:

0.00183

GnomAD4 genome

AF:

0.000703

AC:

107

AN:

152304

Hom.:

Cov.:

AF XY:

0.000712

AC XY:

AN XY:

74468

show subpopulations

Gnomad4 AFR

AF:

0.0000722

Gnomad4 AMR

AF:

0.0000654

Gnomad4 ASJ

AF:

0.0259

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.000176

Gnomad4 OTH

AF:

0.000473

Alfa

AF:

0.00221

Hom.:

Bravo

AF:

0.000676

EpiCase

AF:

0.000491

EpiControl

AF:

0.000356

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:2Benign:4

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

GTP cyclohydrolase I deficiency;C1851920:Dystonia 5

Uncertain:1Benign:1

Benign, criteria provided, single submitter	clinical testing	Invitae	Jan 31, 2024	- -
Uncertain significance, criteria provided, single submitter	clinical testing	Elsea Laboratory, Baylor College of Medicine	Apr 01, 2020	- -

GTP cyclohydrolase I deficiency

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

Jan 12, 2018

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score, this variant could not be ruled out of causing disease and therefore its association with disease required further investigation. A literature search was performed for the gene, cDNA change, and amino acid change (if applicable). No publications were found based on this search. This variant was therefore classified as a variant of unknown significance for this disease. -

GCH1-related disorder

Benign:1

Benign, criteria provided, single submitter

clinical testing

PreventionGenetics, part of Exact Sciences

Nov 06, 2019

This variant is classified as benign based on ACMG/AMP sequence variant interpretation guidelines (Richards et al. 2015 PMID: 25741868, with internal and published modifications). -

not provided

Benign:1

Benign, criteria provided, single submitter

clinical testing

GeneDx

Feb 26, 2021

- -

Dystonia 5

Benign:1

Benign, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

Jan 12, 2018

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score and internal cut-off values, a variant classified as benign is not then subjected to further curation. The score for this variant resulted in a classification of benign for this disease. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

BayesDel_noAF

Benign

-0.92

CADD

Benign

0.0060

DANN

Benign

0.87

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

1.7

Splicing

Name

Calibrated prediction

Score

Prediction

dbscSNV1_ADA

Benign

0.000021

dbscSNV1_RF

Benign

0.0020

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.

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