X-22219074-A-G

Position:

• chrX-22219074-A-G

Variant summary

Our verdict is Pathogenic. Variant got 14 ACMG points: 14P and 0B. PM2 PP3_Strong PP5_Very_Strong

The NM_000444.6(PHEX):​c.1739A>G​(p.His580Arg) variant causes a missense 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. Variant has been reported in ClinVar as Likely pathogenic (★★).

• Frequency: Genomes: not found (cov: 23)
• Consequence: PHEX NM_000444.6 missense
• Clinical Significance: Likely pathogenic criteria provided, multiple submitters, no conflicts P:2
• Conservation: PhyloP100: 8.04

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]

PHEX (HGNC:):

ACMG classification

Verdict is Pathogenic. Variant got 14 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.996
• PP5: Variant X-22219074-A-G is Pathogenic according to our data. Variant chrX-22219074-A-G is described in ClinVar as [Likely_pathogenic]. Clinvar id is 383966.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
PHEX	NM_000444.6	c.1739A>G	p.His580Arg	missense_variant	17/22	ENST00000379374.5	NP_000435.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
PHEX	ENST00000379374.5	c.1739A>G	p.His580Arg	missense_variant	17/22	1	NM_000444.6	ENSP00000368682.4

Frequencies

GnomAD3 genomes Cov.: 23

GnomAD4 exome Cov.: 25

GnomAD4 genome Cov.: 23

ClinVar

Significance: Likely pathogenic

Submissions summary: Pathogenic:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

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

Likely pathogenic, criteria provided, single submitter

clinical testing;provider interpretation

Geisinger Autism and Developmental Medicine Institute, Geisinger Health System

Feb 23, 2018

This variant was identified in a 5 year old female with a genetic and biochemical diagnosis of Sanfilippo syndrome. The variant is absent from the gnomAD database, and it was found to be de novo (with maternity and paternity confirmed). Computational models predict it to be deleterious. Other missense variants involving this codon (H580P) and nearby codons have been reported in the Human Gene Mutation Database. -

not provided Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

GeneDx

Mar 03, 2016

The H580R variant in the PHEX gene has not been reported previously as a pathogenic variant, nor as a benign variant, to our knowledge. However, a missense variant at this same codon (H580P) as well as missense variants in neighboring codons (G579R, G579V, and H584P) have been reported in the Human Gene Mutation Database in association with hypophosphatemic rickets (Stenson et al., 2014), supporting the functional importance of this region of the protein. The H580R variant was not observed in approximately 6500 individuals of European and African American ancestry in the NHLBI Exome Sequencing Project, indicating it is not a common benign variant in these populations. The H580R variant is a conservative amino acid substitution, which occurs at a position that is conserved across species. In silico analysis predicts this variant is probably damaging to the protein structure/function. The H580R variant is a strong candidate for a pathogenic variant, however the possibility it may be a rare benign variant cannot be excluded. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	1.0
BayesDel_addAF	Pathogenic	0.73	D
BayesDel_noAF	Pathogenic	0.81
CADD	Pathogenic	26
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.95	D
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.95	D
M_CAP	Pathogenic	0.97	D
MetaRNN	Pathogenic	1.0	D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Pathogenic	3.2	M
PrimateAI	Pathogenic	0.93	D
PROVEAN	Pathogenic	-7.6	D
REVEL	Pathogenic	0.98
Sift	Pathogenic	0.0	D
Sift4G	Pathogenic	0.0	D
Polyphen		1.0	D
Vest4		0.97
MutPred		0.96		Loss of disorder (P = 0.2042);
MVP		1.0
MPC		1.3
ClinPred		1.0	D
GERP RS		5.9
Varity_R		0.97
gMVP		1.0

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.060		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: rs1057521800; hg19: chrX-22237191;