X-22227581-C-A

Position:

• chrX-22227581-C-A

Variant summary

Our verdict is Uncertain significance. Variant got 4 ACMG points: 4P and 0B. PM2 PP3_Moderate

The NM_000444.6(PHEX):​c.2040C>A​(p.Asn680Lys) 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 Uncertain significance (★★).

• Frequency:
  • Genomes: not found (cov: 23)
  • Exomes 𝑓: 0.0 (0 hom. 0 hem.)
  • Failed GnomAD Quality Control
• Consequence: PHEX NM_000444.6 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:3
• Conservation: PhyloP100: 2.04

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]

PTCHD1-AS (HGNC:):

ACMG classification

Verdict is Uncertain_significance. Variant got 4 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.879

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
PHEX	NM_000444.6	c.2040C>A	p.Asn680Lys	missense_variant	20/22	ENST00000379374.5	NP_000435.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
PHEX	ENST00000379374.5	c.2040C>A	p.Asn680Lys	missense_variant	20/22	1	NM_000444.6	ENSP00000368682.4

Frequencies

GnomAD3 genomes Cov.: 23

GnomAD4 exome Data not reliable, filtered out with message: AC0 AF: 0.00 AC: 0 AN: 1091118 Hom.: 0 Cov.: 28 AF XY: 0.00 AC XY: 0 AN XY: 356778

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: Uncertain significance

Submissions summary: Uncertain:3

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

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

Uncertain significance, criteria provided, single submitter

clinical testing

3billion

May 22, 2022

The variant is not observed in the gnomAD v2.1.1 dataset. Protein truncation variants are a common disease-causing mechanism. Same nucleotide change resulting in same amino acid change has been previously reported to be associated with PHEX related disorder (ClinVar ID: VCV000521768.4, PMID: 10737991). However, the evidence of pathogenicity is insufficient at this time. Therefore, this variant is classified as uncertain significanceaccording to the recommendation of ACMG/AMP guideline. -

Inborn genetic diseases Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

May 12, 2017

- -

not provided Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Dec 05, 2019

In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. Algorithms developed to predict the effect of missense changes on protein structure and function (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be tolerated, but these predictions have not been confirmed by published functional studies and their clinical significance is uncertain. This variant has been observed in individual(s) with hypophosphatemia (PMID: 10737991). ClinVar contains an entry for this variant (Variation ID: 521768). This variant is not present in population databases (ExAC no frequency). This sequence change replaces asparagine with lysine at codon 680 of the PHEX protein (p.Asn680Lys). The asparagine residue is moderately conserved and there is a moderate physicochemical difference between asparagine and lysine. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.82
BayesDel_addAF	Benign	-0.034	T
BayesDel_noAF	Benign	-0.29
CADD	Uncertain	24
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.77	D
FATHMM_MKL	Uncertain	0.91	D
LIST_S2	Uncertain	0.91	D
M_CAP	Pathogenic	0.64	D
MetaRNN	Pathogenic	0.88	D
MetaSVM	Uncertain	0.35	D
MutationAssessor	Benign	1.7	L
MutationTaster	Benign	1.0	D;D;D;D
PrimateAI	Uncertain	0.61	T
PROVEAN	Benign	-2.1	N
REVEL	Uncertain	0.53
Sift	Uncertain	0.0030	D
Sift4G	Benign	0.12	T
Polyphen		0.97	D
Vest4		0.42
MutPred		0.81		Gain of ubiquitination at N680 (P = 0.0289);
MVP		0.90
MPC		0.74
ClinPred		0.88	D
GERP RS		5.4
Varity_R		0.71
gMVP		0.76

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: rs1556151526; hg19: chrX-22245698; COSMIC: COSV65077567;