rs104894436

Variant summary

Our verdict is Uncertain significance. The variant received 3 ACMG points: 3P and 0B. PM1PP2

The NM_000161.3(GCH1):​c.586G>T​(p.Ala196Ser) variant causes a missense change. The variant allele was found at a frequency of 0.0000174 in 1,611,004 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★).

Frequency

Genomes: 𝑓 0.000033 ( 0 hom., cov: 32)
Exomes 𝑓: 0.000016 ( 0 hom. )

Consequence

GCH1
NM_000161.3 missense

Scores

6
8
5

Clinical Significance

Uncertain significance criteria provided, single submitter P:1U:1

Conservation

PhyloP100: 6.17

Publications

2 publications found
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 Gene-Disease associations (from GenCC):
  • dystonia 5
    Inheritance: AD, AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Ambry Genetics, Orphanet, Genomics England PanelApp, Labcorp Genetics (formerly Invitae), G2P
  • GTP cyclohydrolase I deficiency with hyperphenylalaninemia
    Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Labcorp Genetics (formerly Invitae), Genomics England PanelApp, Orphanet, G2P
  • GTP cyclohydrolase I deficiency
    Inheritance: SD, AD Classification: DEFINITIVE Submitted by: ClinGen, Illumina

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Uncertain_significance. The variant received 3 ACMG points.

PM1
In a hotspot region, there are 6 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 9 uncertain in NM_000161.3
PP2
Missense variant in the gene, where a lot of missense mutations are associated with disease in ClinVar. The gene has 30 curated pathogenic missense variants (we use a threshold of 10). The gene has 1 curated benign missense variants. Gene score misZ: 1.5191 (below the threshold of 3.09). Trascript score misZ: 0.62455 (below the threshold of 3.09). GenCC associations: The gene is linked to GTP cyclohydrolase I deficiency, dystonia 5, GTP cyclohydrolase I deficiency with hyperphenylalaninemia.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
GCH1NM_000161.3 linkc.586G>T p.Ala196Ser missense_variant Exon 5 of 6 ENST00000491895.7 NP_000152.1 P30793-1A0A024R642

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
GCH1ENST00000491895.7 linkc.586G>T p.Ala196Ser missense_variant Exon 5 of 6 1 NM_000161.3 ENSP00000419045.2 P30793-1

Frequencies

GnomAD3 genomes
AF:
0.0000328
AC:
5
AN:
152230
Hom.:
0
Cov.:
32
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:
0.00
Gnomad FIN
AF:
0.000188
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.0000441
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.0000398
AC:
10
AN:
251248
AF XY:
0.0000221
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.000139
Gnomad NFE exome
AF:
0.0000616
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000158
AC:
23
AN:
1458774
Hom.:
0
Cov.:
28
AF XY:
0.0000165
AC XY:
12
AN XY:
725966
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33424
American (AMR)
AF:
0.00
AC:
0
AN:
44720
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26126
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39676
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86186
European-Finnish (FIN)
AF:
0.000243
AC:
13
AN:
53420
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5756
European-Non Finnish (NFE)
AF:
0.00000902
AC:
10
AN:
1109180
Other (OTH)
AF:
0.00
AC:
0
AN:
60286
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.462
Heterozygous variant carriers
0
3
5
8
10
13
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome 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
GnomAD4 genome
AF:
0.0000328
AC:
5
AN:
152230
Hom.:
0
Cov.:
32
AF XY:
0.0000538
AC XY:
4
AN XY:
74366
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41460
American (AMR)
AF:
0.00
AC:
0
AN:
15278
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5200
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4832
European-Finnish (FIN)
AF:
0.000188
AC:
2
AN:
10620
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000441
AC:
3
AN:
68046
Other (OTH)
AF:
0.00
AC:
0
AN:
2094
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.485
Heterozygous variant carriers
0
1
1
2
2
3
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:
0.0000245
Hom.:
0
Bravo
AF:
0.00000378
ExAC
AF:
0.0000330
AC:
4

ClinVar

Significance: Uncertain significance
Submissions summary: Pathogenic:1Uncertain:1
Revision: criteria provided, single submitter
LINK: link

Submissions by phenotype

Dystonia 5 Pathogenic:1Uncertain:1
Mar 10, 1999
OMIM
Significance:Pathogenic
Review Status:no assertion criteria provided
Collection Method:literature only

- -

Apr 27, 2017
Illumina Laboratory Services, Illumina
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This variant was observed as part of a predisposition screen in an ostensibly healthy population. A literature search was performed for the gene, cDNA change, and amino acid change (where applicable). Publications were found based on this search. However, the evidence from the literature, in combination with allele frequency data from public databases where available, was not sufficient to rule this variant in or out of causing disease. Therefore, this variant is classified as a variant of unknown significance. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.33
BayesDel_addAF
Pathogenic
0.36
D
BayesDel_noAF
Pathogenic
0.43
CADD
Uncertain
24
DANN
Uncertain
1.0
DEOGEN2
Pathogenic
0.90
D;D;.;D;.
Eigen
Uncertain
0.30
Eigen_PC
Uncertain
0.40
FATHMM_MKL
Pathogenic
0.99
D
LIST_S2
Pathogenic
0.99
.;D;D;.;D
M_CAP
Uncertain
0.18
D
MetaRNN
Uncertain
0.60
D;D;D;D;D
MetaSVM
Pathogenic
1.1
D
MutationAssessor
Benign
1.5
L;L;L;L;L
PhyloP100
6.2
PrimateAI
Uncertain
0.61
T
PROVEAN
Benign
-2.4
.;N;N;N;N
REVEL
Uncertain
0.56
Sift
Benign
0.092
.;T;D;T;T
Sift4G
Uncertain
0.059
T;T;T;T;T
Polyphen
0.38
B;B;B;B;P
Vest4
0.68
MVP
0.98
MPC
2.0
ClinPred
0.50
T
GERP RS
6.2
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.7
Varity_R
0.77
gMVP
0.89
Mutation Taster
=0/100
disease causing

Splicing

Name
Calibrated prediction
Score
Prediction
Splicevardb
2.0
SpliceAI score (max)
0.040
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: rs104894436; hg19: chr14-55312526; API