chrX-22221744-G-A

Position:

• chrX-22221744-G-A

Variant summary

Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PVS1 PM2 PP5_Very_Strong

The ENST00000379374.5(PHEX):​c.1899+1G>A variant causes a splice donor 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 Pathogenic (★★).

• Frequency: Genomes: not found (cov: 23)
• Consequence: PHEX ENST00000379374.5 splice_donor
• Scores: Splicing: ADA: 1.000
• Clinical Significance: Pathogenic criteria provided, multiple submitters, no conflicts P:3
• Conservation: PhyloP100: 9.02

Genes affected

PHEX (HGNC:8918): (phosphate regulating endopeptidase X-linked) The protein encoded by this gene is a transmembrane endopeptidase that belongs to the type II integral membrane zinc-dependent endopeptidase family. The protein is thought to be involved in bone and dentin mineralization and renal phosphate reabsorption. Mutations in this gene cause X-linked hypophosphatemic rickets. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Sep 2013]

PTCHD1-AS (HGNC:37703): (PTCHD1 antisense RNA (head to head))

ACMG classification

Verdict is Pathogenic. Variant got 18 ACMG points.

• PVS1: Splicing +-2 bp (donor or acceptor) variant, LoF is a know mechanism of disease, No cryptic splice site detected. Exon removal results in frameshift change.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant X-22221744-G-A is Pathogenic according to our data. Variant chrX-22221744-G-A is described in ClinVar as [Pathogenic]. Clinvar id is 447937.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chrX-22221744-G-A is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
PHEX	NM_000444.6	c.1899+1G>A		splice_donor_variant		ENST00000379374.5	NP_000435.3
PTCHD1-AS	NR_073010.2	n.1048+5726C>T		intron_variant, non_coding_transcript_variant

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
PHEX	ENST00000379374.5	c.1899+1G>A		splice_donor_variant		1	NM_000444.6	ENSP00000368682	P1
PTCHD1-AS	ENST00000669979.1	n.325+5726C>T		intron_variant, non_coding_transcript_variant

Frequencies

GnomAD3 genomes Cov.: 23

GnomAD4 exome Cov.: 28

GnomAD4 genome Cov.: 23

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:3

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not provided Pathogenic:2

Pathogenic, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	Mar 01, 2023	For these reasons, this variant has been classified as Pathogenic. Studies have shown that disruption of this splice site results in skipping of exon 18 and introduces a premature termination codon (PMID: 31102713). The resulting mRNA is expected to undergo nonsense-mediated decay. ClinVar contains an entry for this variant (Variation ID: 447937). Disruption of this splice site has been observed in individuals with hypophosphatemia (PMID: 19219621, 21050253). This variant is not present in population databases (gnomAD no frequency). This sequence change affects a donor splice site in intron 18 of the PHEX gene. RNA analysis indicates that disruption of this splice site induces altered splicing and may result in an absent or disrupted protein product. -
Pathogenic, criteria provided, single submitter	clinical testing	Athena Diagnostics	Jan 17, 2017	- -

Familial X-linked hypophosphatemic vitamin D refractory rickets Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Mendelics

May 28, 2019

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.74	D
BayesDel_noAF	Pathogenic	0.39
CADD	Pathogenic	32
DANN	Uncertain	1.0
FATHMM_MKL	Pathogenic	0.99	D
MutationTaster	Benign	1.0	D;D;D;D
GERP RS		6.0

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.95
SpliceAI score (max)		0.99		Details are displayed if max score is > 0.2
DS_DL_spliceai		0.99		Position offset: -1

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

Publications

LitVar

Other links and lift over

dbSNP: rs1556138769; hg19: chrX-22239861;