rs28937882

chr12-4370564-G-Achr12-4370564-G-T

Variant summary

Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PM1 PM2 PM5 PP3_Strong PP5_Very_Strong

The NM_020638.3(FGF23):c.535C>T(p.Arg179Trp) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000657 in 152,124 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Likely pathogenic (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R179Q) has been classified as Pathogenic.

• Frequency: Genomes: 𝑓 0.0000066 (0 hom., cov: 31)
• Consequence: FGF23 NM_020638.3 missense
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:4
• Conservation: PhyloP100: 3.13

Genes affected

FGF23 (HGNC:3680): (fibroblast growth factor 23) This gene encodes a member of the fibroblast growth factor family of proteins, which possess broad mitogenic and cell survival activities and are involved in a variety of biological processes. The product of this gene regulates phosphate homeostasis and transport in the kidney. The full-length, functional protein may be deactivated via cleavage into N-terminal and C-terminal chains. Mutation of this cleavage site causes autosomal dominant hypophosphatemic rickets (ADHR). Mutations in this gene are also associated with hyperphosphatemic familial tumoral calcinosis (HFTC). [provided by RefSeq, Feb 2013]

ACMG classification

Verdict is Pathogenic. Variant got 18 ACMG points.

• PM1: In a site Cleavage; by proprotein convertases (size 1) in uniprot entity FGF23_HUMAN there are 4 pathogenic changes around while only 0 benign (100%) in NM_020638.3
• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr12-4370563-C-T is described in ClinVar as [Pathogenic]. Clinvar id is 36135.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.956
• PP5: Variant 12-4370564-G-A is Pathogenic according to our data. Variant chr12-4370564-G-A is described in ClinVar as [Likely_pathogenic]. Clinvar id is 5026.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr12-4370564-G-A is described in Lovd as [Pathogenic]. Variant chr12-4370564-G-A is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
FGF23	NM_020638.3	c.535C>T	p.Arg179Trp	missense_variant	3/3	ENST00000237837.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
FGF23	ENST00000237837.2	c.535C>T	p.Arg179Trp	missense_variant	3/3	1	NM_020638.3	P1

Frequencies

GnomAD3 genomes AF: 0.00000657 AC: 1 AN: 152124 Hom.: 0 Cov.: 31

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.0000147

Gnomad OTH AF: 0.00

GnomAD4 exome Cov.: 33

GnomAD4 genome AF: 0.00000657 AC: 1 AN: 152124 Hom.: 0 Cov.: 31 AF XY: 0.0000135 AC XY: 1 AN XY: 74302

Gnomad4 AFR AF: 0.00

Gnomad4 AMR AF: 0.00

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.0000147

Gnomad4 OTH AF: 0.00

Bravo AF: 0.00000378

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:4

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Autosomal dominant hypophosphatemic rickets Pathogenic:2

Pathogenic, no assertion criteria provided	literature only	OMIM	Nov 01, 2000	- -
Pathogenic, criteria provided, single submitter	clinical testing	Institute of Human Genetics Munich, Klinikum Rechts Der Isar, TU München	Dec 05, 2013	- -

not provided Pathogenic:2

Likely pathogenic, criteria provided, single submitter	clinical testing	GeneDx	Nov 20, 2015	The R179W variant that is likely pathogenic has been published previously in association with autosomal dominant hypophosphateaemic rickets (Imel et al., 2011; ADHR consortium, 2000). It was not observed in approximately 6,500 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 R179W variant is a non-conservative amino acid substitution, which is likely to impact secondary protein structure as these residues differ in polarity, charge, size and/or other properties. This substitution occurs at a position that is conserved across species and is cleaved by proprotein convertases (Komaba et al., 2012). In silico analysis predicts this variant is probably damaging to the protein structure/function. Missense variants at the same codon (R179Q) and in nearby residues (R176W/Q) have been reported in the Human Gene Mutation Database in association with autosomal dominant hypophosphatemic rickets (Stenson et al., 2014), supporting the functional importance of this region of the protein. Therefore, this variant is likely pathogenic; however, the possibility that it is benign cannot be excluded. -
Pathogenic, criteria provided, single submitter	clinical testing	Invitae	Jan 24, 2024	This sequence change replaces arginine, which is basic and polar, with tryptophan, which is neutral and slightly polar, at codon 179 of the FGF23 protein (p.Arg179Trp). This variant is not present in population databases (gnomAD no frequency). This missense change has been observed in individuals with autosomal dominant hypophosphatemic rickets (PMID: 11062477, 21880793, 31486862, 32415663). It has also been observed to segregate with disease in related individuals. ClinVar contains an entry for this variant (Variation ID: 5026). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) has been performed at Invitae for this missense variant, however the output from this modeling did not meet the statistical confidence thresholds required to predict the impact of this variant on FGF23 protein function. This variant disrupts the p.Arg179 amino acid residue in FGF23. Other variant(s) that disrupt this residue have been determined to be pathogenic (PMID: 11062477, 21880793, 26186302). This suggests that this residue is clinically significant, and that variants that disrupt this residue are likely to be disease-causing. For these reasons, this variant has been classified as Pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Uncertain	0.39
BayesDel_addAF	Pathogenic	0.26	D
BayesDel_noAF	Uncertain	0.13
Cadd	Pathogenic	32
Dann	Uncertain	1.0
DEOGEN2	Pathogenic	0.84	D
Eigen	Uncertain	0.38
Eigen_PC	Uncertain	0.32
FATHMM_MKL	Uncertain	0.95	D
LIST_S2	Uncertain	0.91	D
M_CAP	Pathogenic	0.30	D
MetaRNN	Pathogenic	0.96	D
MetaSVM	Uncertain	0.56	D
MutationAssessor	Uncertain	2.3	M
MutationTaster	Benign	1.0	A
PrimateAI	Uncertain	0.69	T
PROVEAN	Uncertain	-3.0	D
REVEL	Pathogenic	0.67
Sift	Uncertain	0.0030	D
Sift4G	Pathogenic	0.0	D
Polyphen		1.0	D
Vest4		0.85
MutPred		0.80		Loss of solvent accessibility (P = 0.0468);
MVP		0.90
MPC		1.0
ClinPred		0.95	D
GERP RS		4.0
Varity_R		0.62
gMVP		0.54

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: rs28937882; hg19: chr12-4479730; COSMIC: COSV52977924;