X-134473357-A-G

Variant summary

Our verdict is Pathogenic. Variant got 15 ACMG points: 15P and 0B. PVS1 PM2 PP3_Strong PP5

The NM_000194.3(HPRT1):c.28-2A>G variant causes a splice acceptor change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Likely pathogenic (no stars).

• Frequency:
  • Genomes: not found (cov: 23)
  • Exomes 𝑓: 0.0 (0 hom. 0 hem.)
  • Failed GnomAD Quality Control
• Consequence: HPRT1 NM_000194.3 splice_acceptor
• Scores: Splicing: ADA: 1.000
• Clinical Significance: Likely pathogenic no assertion criteria provided P:1
• Conservation: PhyloP100: 9.32

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 15 ACMG points.

• PVS1: Splicing variant, LoF is a know mechanism of disease, Cryptic splice site detected, with MaxEntScore 5.3, offset of 5, new splice context is: atatttctttttcggattAGtga. Cryptic site results in frameshift change. If cryptic site found is not functional and variant results in exon loss, it results in frameshift change.
• PM2: Very rare variant in population databases, with high coverage
• PP3: Splicing scoreres supports a deletorius effect: Scorers claiming Pathogenic: dbscSNV1_ADA, dbscSNV1_RF, max_spliceai. No scorers claiming Uncertain. No scorers claiming Benign.
• PP5: Variant X-134473357-A-G is Pathogenic according to our data. Variant chrX-134473357-A-G is described in ClinVar as [Likely_pathogenic]. Clinvar id is 2664053.Status of the report is no_assertion_criteria_provided, 0 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
HPRT1	NM_000194.3	c.28-2A>G		splice_acceptor_variant		ENST00000298556.8

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
HPRT1	ENST00000298556.8	c.28-2A>G		splice_acceptor_variant		1	NM_000194.3	P1
HPRT1	ENST00000462974.5	n.186-2A>G		splice_acceptor_variant, non_coding_transcript_variant		3
HPRT1	ENST00000475720.1			upstream_gene_variant		3

Frequencies

GnomAD3 genomes Cov.: 23

GnomAD4 exome Data not reliable, filtered out with message: AC0;AS_VQSR AF: 0.00 AC: 0 AN: 969824 Hom.: 0 Cov.: 19 AF XY: 0.00 AC XY: 0 AN XY: 287544

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: 0.00

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 23

ClinVar

Significance: Likely pathogenic

Submissions summary: Pathogenic:1

Revision: no assertion criteria provided

Submissions by phenotype

Lesch-Nyhan syndrome Pathogenic:1

Likely pathogenic, no assertion criteria provided

clinical testing

Zotz-Klimas Genetics Lab, MVZ Zotz Klimas

Nov 24, 2023

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.74	D
BayesDel_noAF	Pathogenic	0.29
Cadd	Pathogenic	34
Dann	Uncertain	0.99
FATHMM_MKL	Pathogenic	1.0	D
MutationTaster	Benign	1.0	D
GERP RS		4.7

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.93
SpliceAI score (max)		1.0		Details are displayed if max score is > 0.2
DS_AG_spliceai		0.79		Position offset: 7
DS_AL_spliceai		1.0		Position offset: 2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

No publications associated with this variant yet.

Other links and lift over

hg19: chrX-133607387;