4-1804372-A-G
Variant summary
Our verdict is Pathogenic. Variant got 14 ACMG points: 14P and 0B. PM2PP3_StrongPP5_Very_Strong
The NM_000142.5(FGFR3):c.1118A>G(p.Tyr373Cys) 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 Pathogenic (★★).
Frequency
Consequence
NM_000142.5 missense
Scores
Clinical Significance
Conservation
Genome browser will be placed here
ACMG classification
Verdict is Pathogenic. Variant got 14 ACMG points.
Transcripts
RefSeq
Ensembl
Frequencies
GnomAD3 genomes Cov.: 34
GnomAD4 exome Cov.: 35
GnomAD4 genome Cov.: 34
ClinVar
Submissions by phenotype
not provided Pathogenic:8
- -
This sequence change replaces tyrosine, which is neutral and polar, with cysteine, which is neutral and slightly polar, at codon 373 of the FGFR3 protein (p.Tyr373Cys). This variant is not present in population databases (gnomAD no frequency). This missense change has been observed in individual(s) with thanatophoric dysplasia (PMID: 8845844, 24476948, 25614871, 28249712). In at least one individual the variant was observed to be de novo. ClinVar contains an entry for this variant (Variation ID: 16342). Invitae Evidence Modeling incorporating data from in vitro experimental studies (internal data) indicates that this missense variant is expected to disrupt FGFR3 function with a positive predictive value of 95%. Experimental studies have shown that this missense change affects FGFR3 function (PMID: 19088846, 23200862, 24419316, 25606676). For these reasons, this variant has been classified as Pathogenic. -
- -
Published functional studies indicate that the Y373C variant causes increased activation of the receptor in the absence of the ligand (Ronchetti et al., 2001; Qi et al., 2014); Not observed in large population cohorts (Lek et al., 2016); In silico analysis, which includes protein predictors and evolutionary conservation, supports a deleterious effect; This variant is associated with the following publications: (PMID: 21273588, 19331127, 11851976, 9843049, 30692697, 8845844, 30712878, 25606676, 24419316, 24476948, 22045636, 11429702, 24657641, 19088846, 23200862, 17509076, 17320202, 14715624, 11526491, 26858415, 29593476, 28249712, 19789973, 9438390, 31299979) -
- -
- -
- -
The FGFR3 c.1118A>G; p.Tyr373Cys variant (rs121913485) is reported in the literature in multiple individuals affected with thanatophoric dwarfism (Brodie 1999, Rousseau 1996), and it was identified in a cohort of fetal skeletal dysplasia patients (Carass 2014). This variant is reported in ClinVar (Variation ID: 16342), and it is also absent from the Genome Aggregation Database, indicating it is not a common polymorphism. Carass et al. found the p.Tyr373Cys variant to be de novo in a male fetus with features consistent with lethal skeletal dysplasia. Furthermore, a mouse model of the p.Tyr373Cys variant displays features similar to achondroplasia (Di Rocco 2014, Lorget 2012) and in vitro studies performed on the p.Tyr373Cys variant in human chondrocytes show decreased proliferation (Krejci 2008). The tyrosine at codon 373 is moderately conserved, and computational analyses predict that this variant is deleterious (REVEL: 0.800). Based on available information, this variant is considered to be pathogenic. References: Brodie SG et al. Platyspondylic lethal skeletal dysplasia, San Diego type, is caused by FGFR3 mutations. Am J Med Genet. 1999 Jun 11;84(5):476-80. PMID: 10360402. Carss et al. Exome sequencing improves genetic diagnosis of structural fetal abnormalities revealed by ultrasound. Hum Mol Genet. 2014; 23(12):3269-3277. PMID: 24476948. Di Rocco et al. FGFR3 mutation causes abnormal membranous ossification in achondroplasia. Hum Mol Genet. 2014; 23(11):2914-2925. PMID: 24419316. Krejci et al. Analysis of STAT1 Activation by Six FGFR3 Mutants Associated with Skeletal Dysplasia Undermines Dominant Role of STAT1 in FGFR3 Signaling in Cartilage. PLoS One. 2008;3(12):e3961. PMID: 19088846. Lorget F et al. Evaluation of the therapeutic potential of a CNP analog in a Fgfr3 mouse model recapitulating achondroplasia. Am J Hum Genet. 2012 Dec 7;91(6):1108-14. PMID: 23200862. Rousseau et al. Missense FGFR3 mutations create cysteine residues in thanatophoric dwarfism type I (TD1). Hum Mol Genet. 1996; 5(4):509-512. PMID: 8845844. -
Thanatophoric dysplasia type 1 Pathogenic:7Other:1
The FGFR3 c.1118A>G variant is a single nucleotide change in exon 9/18 of the FGFR3 gene, which is predicted to change the amino acid tyrosine at position 373 in the protein to cysteine. This variant has been identified as a de novo variant in this patient (PS2). This variant is absent from population databases (PM2), but has been reported numerous times in the literature in association with Thanatophoric dwarfism and Achondroplasia (e.g. PMID: 8845844, 24476948, 28249712) (PS4). It is the second most common cause of this condition (PMID:25614871). The variant has been reported as Pathogenic by other diagnostic laboratories (ClinVar Variation ID: 16342) and is listed in HGMD as disease causing (CM960657). Computational predictions support a deleterious effect on the gene or gene product (PP3). Functional studies reproducing the equivalent variant in mouse models mirrored the clinical presentation seen in humans (Lorget et al 2012 PMID: 23200862) (PS3). -
- -
- -
- -
- -
- -
PM2_Supporting+PS2_Moderate+PS3+PS4 -
- -
See cases Pathogenic:1
- -
FGFR3-related disorder Pathogenic:1
The FGFR3 c.1118A>G variant is predicted to result in the amino acid substitution p.Tyr373Cys. This variant has been reported to be one of the most common pathogenic variants for thanatophoric dysplasia (Rousseau et al. 1996. PubMed ID: 8845844; Brodie et al. 1999. PubMed ID: 10360402; Xue et al. 2014. PubMed ID: 25614871). Functional studies also support its pathogenicity (Foldynova-Trantirkova et al. 2012. PubMed ID: 22045636; Di Rocco et al. 2014. PubMed ID: 24419316). This variant has not been reported in a large population database, indicating this variant is rare. This variant is interpreted as pathogenic. -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at