NM_000161.3:c.*1628A>C

Variant names:

• chr14-54842389-T-G
• rs185031007
• NM_000161.3:c.*1628A>C

Variant summary

Our verdict is Likely benign. The variant received -5 ACMG points: 0P and 5B. BP4_Strong BS1_Supporting

The NM_000161.3(GCH1):​c.*1628A>C variant causes a 3 prime UTR change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000991 in 152,348 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★).

• Frequency:
  • Genomes: 𝑓 0.00099 (0 hom., cov: 32)
  • Exomes 𝑓: 0.0 (0 hom.)
  • Failed GnomAD Quality Control
• Consequence: GCH1 NM_000161.3 3_prime_UTR
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:3
• Conservation: PhyloP100: 0.189
• Publications: 0 publications found

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: Genomics England PanelApp, Labcorp Genetics (formerly Invitae), Ambry Genetics, G2P, Orphanet
• GTP cyclohydrolase I deficiency

  Inheritance: AD, SD Classification: DEFINITIVE Submitted by: Illumina, ClinGen
• GTP cyclohydrolase I deficiency with hyperphenylalaninemia

  Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Genomics England PanelApp, Labcorp Genetics (formerly Invitae), Orphanet, G2P

ACMG classification

Our verdict: Likely_benign. The variant received -5 ACMG points.

• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.52).
• BS1: Variant frequency is greater than expected in population nfe. GnomAd4 allele frequency = 0.000991 (151/152348) while in subpopulation NFE AF = 0.00194 (132/68028). AF 95% confidence interval is 0.00167. There are 0 homozygotes in GnomAd4. There are 55 alleles in the male GnomAd4 subpopulation. Median coverage is 32. This position passed quality control check. Existence of Clinvar submissions makes me limit the strength of this signal to Supporting

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_000161.3. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	GCH1	NM_000161.3	MANE Select	c.*1628A>C		3_prime_UTR	Exon 6 of 6	NP_000152.1	P30793-1
	GCH1	NM_001024024.2		c.*682A>C		3_prime_UTR	Exon 7 of 7	NP_001019195.1	P30793-1
	GCH1	NM_001024070.2		c.*678A>C		3_prime_UTR	Exon 7 of 7	NP_001019241.1	P30793-4

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	GCH1	ENST00000491895.7	TSL:1 MANE Select	c.*1628A>C		3_prime_UTR	Exon 6 of 6	ENSP00000419045.2	P30793-1
	GCH1	ENST00000395514.5	TSL:1	c.*682A>C		3_prime_UTR	Exon 7 of 7	ENSP00000378890.1	P30793-1
	GCH1	ENST00000543643.6	TSL:1	c.*678A>C		3_prime_UTR	Exon 7 of 7	ENSP00000444011.2	P30793-4

Frequencies

GnomAD3 genomes AF: 0.000992 AC: 151 AN: 152230 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.000362

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.0000654

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: 0.00194

Gnomad OTH AF: 0.000478

GnomAD4 exome Data not reliable, filtered out with message: AC0 AF: 0.00 AC: 0 AN: 436 Hom.: 0 Cov.: 0 AF XY: 0.00 AC XY: 0 AN XY: 262

African (AFR) AC: 0 AN: 0

American (AMR) AC: 0 AN: 0

Ashkenazi Jewish (ASJ) AC: 0 AN: 0

East Asian (EAS) AC: 0 AN: 0

South Asian (SAS) AC: 0 AN: 0

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 426

Middle Eastern (MID) AC: 0 AN: 0

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 6

Other (OTH) AF: 0.00 AC: 0 AN: 4

GnomAD4 genome AF: 0.000991 AC: 151 AN: 152348 Hom.: 0 Cov.: 32 AF XY: 0.000738 AC XY: 55 AN XY: 74504

African (AFR) AF: 0.000361 AC: 15 AN: 41588

American (AMR) AF: 0.0000653 AC: 1 AN: 15306

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3470

East Asian (EAS) AF: 0.00 AC: 0 AN: 5192

South Asian (SAS) AF: 0.00 AC: 0 AN: 4824

European-Finnish (FIN) AF: 0.000188 AC: 2 AN: 10620

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 294

European-Non Finnish (NFE) AF: 0.00194 AC: 132 AN: 68028

Other (OTH) AF: 0.000473 AC: 1 AN: 2114

Alfa AF: 0.00106 Hom.: 0

Bravo AF: 0.00107

ClinVar

ClinVar submissions as Germline

Significance: Uncertain significance

Revision: criteria provided, multiple submitters, no conflicts

Pathogenic	VUS	Benign	Condition
-	1	-	Dystonia 5 (1)
-	1	-	Dystonia 5;CN305333:GTP cyclohydrolase I deficiency with hyperphenylalaninemia (1)
-	1	-	GTP cyclohydrolase I deficiency (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.52
CADD	Benign	9.4
DANN	Benign	0.80
PhyloP100		0.19

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

Other links and lift over

dbSNP: rs185031007; hg19: chr14-55309107;