rs104893866

Positions:

• chr4-17492328-T-C

Variant summary

Our verdict is Pathogenic. Variant got 10 ACMG points: 10P and 0B. PM1 PM2 PP3_Strong PP5_Moderate

The NM_000320.3(QDPR):​c.449A>G​(p.Tyr150Cys) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000274 in 1,461,768 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Pathogenic (★). Synonymous variant affecting the same amino acid position (i.e. Y150Y) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.0000027 (0 hom.)
• Consequence: QDPR NM_000320.3 missense
• Clinical Significance: Pathogenic criteria provided, single submitter P:2
• Conservation: PhyloP100: 7.42

Genes affected

QDPR (HGNC:9752): (quinoid dihydropteridine reductase) This gene encodes the enzyme dihydropteridine reductase, which catalyzes the NADH-mediated reduction of quinonoid dihydrobiopterin. This enzyme is an essential component of the pterin-dependent aromatic amino acid hydroxylating systems. Mutations in this gene resulting in QDPR deficiency include aberrant splicing, amino acid substitutions, insertions, or premature terminations. Dihydropteridine reductase deficiency presents as atypical phenylketonuria due to insufficient production of biopterin, a cofactor for phenylalanine hydroxylase. [provided by RefSeq, Jul 2008]

ACMG classification

Verdict is Pathogenic. Variant got 10 ACMG points.

• PM1: In a hotspot region, there are 3 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 3 uncertain in NM_000320.3
• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.97
• PP5: Variant 4-17492328-T-C is Pathogenic according to our data. Variant chr4-17492328-T-C is described in ClinVar as [Pathogenic]. Clinvar id is 494.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
QDPR	NM_000320.3	c.449A>G	p.Tyr150Cys	missense_variant	5/7	ENST00000281243.10
QDPR	NM_001306140.2	c.356A>G	p.Tyr119Cys	missense_variant	4/6
QDPR	NR_156494.2	n.473-1583A>G		intron_variant, non_coding_transcript_variant

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
QDPR	ENST00000281243.10	c.449A>G	p.Tyr150Cys	missense_variant	5/7	1	NM_000320.3	P1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 0.00000274 AC: 4 AN: 1461768 Hom.: 0 Cov.: 31 AF XY: 0.00000275 AC XY: 2 AN XY: 727190

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000270

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 33

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:2

Revision: criteria provided, single submitter

Submissions by phenotype

Dihydropteridine reductase deficiency Pathogenic:1

Pathogenic, no assertion criteria provided

literature only

OMIM

Jan 01, 1998

- -

not provided Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

GeneDx

Aug 24, 2020

Not observed in large population cohorts (Lek et al., 2016); Missense variants in this gene are often considered pathogenic (Stenson et al., 2014); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; This variant is associated with the following publications: (PMID: 31589614, 31980526, 11153907, 9744478, 16917893, 22325981, 10896287, 27246466, 21890392) -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.98
BayesDel_addAF	Pathogenic	0.55	D
BayesDel_noAF	Pathogenic	0.56
CADD	Pathogenic	30
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.94	D;.
Eigen	Pathogenic	0.80
Eigen_PC	Pathogenic	0.69
FATHMM_MKL	Uncertain	0.96	D
LIST_S2	Pathogenic	0.98	D;D
M_CAP	Pathogenic	0.79	D
MetaRNN	Pathogenic	0.97	D;D
MetaSVM	Pathogenic	1.0	D
MutationAssessor	Uncertain	2.8	M;.
MutationTaster	Benign	1.0	A;A;A;A
PrimateAI	Pathogenic	0.82	D
PROVEAN	Pathogenic	-8.3	D;D
REVEL	Pathogenic	0.97
Sift	Pathogenic	0.0	D;D
Sift4G	Pathogenic	0.0	D;D
Polyphen		1.0	D;.
Vest4		0.99
MutPred		0.80		Loss of glycosylation at K154 (P = 0.0403);.;
MVP		0.99
MPC		0.83
ClinPred		1.0	D
GERP RS		5.3
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.99
gMVP		0.98

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

LitVar

Other links and lift over

dbSNP: rs104893866; hg19: chr4-17493951;