rs137852477

Positions:

• chrX-134490199-T-G

Variant summary

Our verdict is Pathogenic. Variant got 11 ACMG points: 11P and 0B. PM1 PM2 PM5 PP3_Strong PP5

The NM_000194.3(HPRT1):​c.396T>G​(p.Ile132Met) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Pathogenic,other (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. I132T) has been classified as Likely pathogenic.

• Frequency: Genomes: not found (cov: 22)
• Consequence: HPRT1 NM_000194.3 missense
• Clinical Significance: Pathogenic; other no assertion criteria provided P:1 O:1
• Conservation: PhyloP100: 1.09

Genes affected

HPRT1 (HGNC:5157): (hypoxanthine phosphoribosyltransferase 1) The protein encoded by this gene is a transferase, which catalyzes conversion of hypoxanthine to inosine monophosphate and guanine to guanosine monophosphate via transfer of the 5-phosphoribosyl group from 5-phosphoribosyl 1-pyrophosphate. This enzyme plays a central role in the generation of purine nucleotides through the purine salvage pathway. Mutations in this gene result in Lesch-Nyhan syndrome or gout.[provided by RefSeq, Jun 2009]

ACMG classification

Verdict is Pathogenic. Variant got 11 ACMG points.

• PM1: In a chain Hypoxanthine-guanine phosphoribosyltransferase (size 216) in uniprot entity HPRT_HUMAN there are 37 pathogenic changes around while only 0 benign (100%) in NM_000194.3
• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chrnull-null-null-null is described in UniProt as null.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.976
• PP5: Variant X-134490199-T-G is Pathogenic according to our data. Variant chrX-134490199-T-G is described in ClinVar as [Pathogenic, other]. Clinvar id is 10029.Status of the report is no_assertion_criteria_provided, 0 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
HPRT1	NM_000194.3	c.396T>G	p.Ile132Met	missense_variant	5/9	ENST00000298556.8	NP_000185.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
HPRT1	ENST00000298556.8	c.396T>G	p.Ile132Met	missense_variant	5/9	1	NM_000194.3	ENSP00000298556	P1
HPRT1	ENST00000462974.5	n.554T>G		non_coding_transcript_exon_variant	5/8	3
HPRT1	ENST00000475720.1	n.354T>G		non_coding_transcript_exon_variant	4/8	3

Frequencies

GnomAD3 genomes Cov.: 22

GnomAD4 exome Cov.: 15

GnomAD4 genome Cov.: 22

ClinVar

Significance: Pathogenic; other

Submissions summary: Pathogenic:1 Other:1

Revision: no assertion criteria provided

Submissions by phenotype

Partial hypoxanthine-guanine phosphoribosyltransferase deficiency Pathogenic:1

Pathogenic, no assertion criteria provided

literature only

OMIM

May 01, 1988

- -

HPRT ANN ARBOR Other:1

other, no assertion criteria provided

literature only

OMIM

Sep 10, 2020

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.77
BayesDel_addAF	Pathogenic	0.63	D
BayesDel_noAF	Pathogenic	0.67
CADD	Uncertain	23
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.99	D
FATHMM_MKL	Uncertain	0.96	D
LIST_S2	Uncertain	0.97	D
M_CAP	Pathogenic	0.59	D
MetaRNN	Pathogenic	0.98	D
MetaSVM	Pathogenic	0.96	D
MutationAssessor	Pathogenic	4.1	H
MutationTaster	Benign	1.0	A
PrimateAI	Uncertain	0.77	T
PROVEAN	Uncertain	-2.5	D
REVEL	Pathogenic	0.81
Sift	Uncertain	0.0010	D
Sift4G	Uncertain	0.0020	D
Polyphen		0.93	P
Vest4		0.72
MutPred		0.90		Gain of ubiquitination at K128 (P = 0.0913);
MVP		1.0
MPC		2.5
ClinPred		0.94	D
GERP RS		1.3
Varity_R		0.95
gMVP		0.93

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.010		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: rs137852477; hg19: chrX-133624229;