4-1804372-A-G

Variant names:

• chr4-1804372-A-G
• rs121913485
• NM_000142.5:c.1118A>G

Variant summary

Our verdict is Pathogenic. The variant received 16 ACMG points: 16P and 0B. PM1 PM2 PP3_Strong PP5_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: Genomes: not found (cov: 34)
• Consequence: FGFR3 NM_000142.5 missense
• Clinical Significance: Pathogenic criteria provided, multiple submitters, no conflicts P:19 O:1
• Conservation: PhyloP100: 3.54
• Publications: 330 publications found

Genes affected

FGFR3 (HGNC:3690): (fibroblast growth factor receptor 3) This gene encodes a member of the fibroblast growth factor receptor (FGFR) family, with its amino acid sequence being highly conserved between members and among divergent species. FGFR family members differ from one another in their ligand affinities and tissue distribution. A full-length representative protein would consist of an extracellular region, composed of three immunoglobulin-like domains, a single hydrophobic membrane-spanning segment and a cytoplasmic tyrosine kinase domain. The extracellular portion of the protein interacts with fibroblast growth factors, setting in motion a cascade of downstream signals, ultimately influencing mitogenesis and differentiation. This particular family member binds acidic and basic fibroblast growth hormone and plays a role in bone development and maintenance. Mutations in this gene lead to craniosynostosis and multiple types of skeletal dysplasia. [provided by RefSeq, Aug 2017]

FGFR3 Gene-Disease associations (from GenCC):

• achondroplasia

  Inheritance: AD Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: G2P, ClinGen, Genomics England PanelApp, Orphanet, Ambry Genetics, Labcorp Genetics (formerly Invitae)
• Crouzon syndrome-acanthosis nigricans syndrome

  Inheritance: AD Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: G2P, Ambry Genetics, Orphanet, Genomics England PanelApp, Labcorp Genetics (formerly Invitae), PanelApp Australia, ClinGen
• hypochondroplasia

  Inheritance: AD Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Ambry Genetics, G2P, ClinGen, Labcorp Genetics (formerly Invitae), Orphanet
• lacrimoauriculodentodigital syndrome 2

  Inheritance: AD Classification: DEFINITIVE Submitted by: G2P
• Muenke syndrome

  Inheritance: AD Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Orphanet, Ambry Genetics, PanelApp Australia, Labcorp Genetics (formerly Invitae), Genomics England PanelApp, ClinGen, G2P
• thanatophoric dysplasia type 1

  Inheritance: AD Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: G2P, Ambry Genetics, Genomics England PanelApp, Orphanet, ClinGen
• thanatophoric dysplasia type 2

  Inheritance: AD Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Orphanet, ClinGen, Genomics England PanelApp, G2P, Labcorp Genetics (formerly Invitae)
• camptodactyly-tall stature-scoliosis-hearing loss syndrome

  Inheritance: AR, AD, SD Classification: DEFINITIVE, STRONG, MODERATE, SUPPORTIVE, LIMITED Submitted by: Ambry Genetics, G2P, Orphanet, Labcorp Genetics (formerly Invitae), ClinGen
• severe achondroplasia-developmental delay-acanthosis nigricans syndrome

  Inheritance: AD Classification: STRONG, MODERATE, SUPPORTIVE Submitted by: Orphanet, Labcorp Genetics (formerly Invitae), ClinGen
• isolated brachycephaly

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• isolated plagiocephaly

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• LADD syndrome

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• LADD syndrome 1

  Inheritance: AD Classification: LIMITED Submitted by: Labcorp Genetics (formerly Invitae)

ACMG classification

Our verdict: Pathogenic. The variant received 16 ACMG points.

• PM1: In a hotspot region, there are 5 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 1 benign, 16 uncertain in NM_000142.5
• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.984
• PP5: Variant 4-1804372-A-G is Pathogenic according to our data. Variant chr4-1804372-A-G is described in ClinVar as Pathogenic. ClinVar VariationId is 16342.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_000142.5. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	FGFR3	NM_000142.5	MANE Select	c.1118A>G	p.Tyr373Cys	missense	Exon 9 of 18	NP_000133.1
	FGFR3	NM_001163213.2		c.1124A>G	p.Tyr375Cys	missense	Exon 9 of 18	NP_001156685.1
	FGFR3	NM_001354809.2		c.1118A>G	p.Tyr373Cys	missense	Exon 9 of 18	NP_001341738.1

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	FGFR3	ENST00000440486.8	TSL:5 MANE Select	c.1118A>G	p.Tyr373Cys	missense	Exon 9 of 18	ENSP00000414914.2
	FGFR3	ENST00000481110.7	TSL:1	c.1118A>G	p.Tyr373Cys	missense	Exon 9 of 17	ENSP00000420533.2
	FGFR3	ENST00000260795.8	TSL:1	n.*174A>G		non_coding_transcript_exon	Exon 10 of 19	ENSP00000260795.3

Frequencies

GnomAD3 genomes Cov.: 34

GnomAD4 exome Cov.: 35

GnomAD4 genome Cov.: 34

Alfa AF: 0.000531 Hom.: 0

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:19 Other:1

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Thanatophoric dysplasia type 1 Pathogenic:8 Other:1

GeneReviews

Significance: not provided

Review Status: no classification provided

Collection Method: literature only

Nov 16, 1998

OMIM

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: literature only

Kasturba Medical College, Manipal, Kasturba Medical College, Manipal, Manipal Academy of Higher Education, Manipal, India

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Nov 22, 2021

Genetics and Molecular Pathology, SA Pathology

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

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).

Apr 16, 2021

Medical Genetics Center, Maternal and Child Health Hospital of Hubei Province

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Jun 12, 2024

Department of Genetics, Sultan Qaboos University Hospital

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: curation

Aug 09, 2024

3billion

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The variant is not observed in the gnomAD v4.0.0 dataset. Predicted Consequence/Location: Missense changes are a common disease-causing mechanism. In silico tool predictions suggest damaging effect of the variant on gene or gene product [REVEL: 0.80 (>=0.6, sensitivity 0.68 and specificity 0.92); 3Cnet: 0.99 (>=0.6, sensitivity 0.72 and precision 0.9)]. The same nucleotide change resulting in the same amino acid change has been previously reported as pathogenic/likely pathogenic with strong evidence (ClinVar ID: VCV000016342 /PMID: 8845844). The variant has been observed in multiple (>3) similarly affected unrelated individuals (PMID: 25614871). Therefore, this variant is classified as Pathogenic according to the recommendation of ACMG/AMP guideline.

Juno Genomics, Hangzhou Juno Genomics, Inc

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Absent from controls (or at extremely low frequency if recessive) in Genome Aggregation Database, Exome Sequencing Project, 1000 Genomes Project, or Exome Aggregation Consortium.;De novo (both maternity and paternity confirmed) in a patient with the disease and no family history.;Well-established in vitro or in vivo functional studies supportive of a damaging effect on the gene or gene product.;The prevalence of the variant in affected individuals is significantly increased compared to the prevalence in controls.

Nov 18, 2018

Baylor Genetics

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: clinical testing

not provided Pathogenic:8

Jan 25, 2017

Clinical Genetics and Genomics, Karolinska University Hospital

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Oct 23, 2020

Institute of Medical Genetics and Applied Genomics, University Hospital Tübingen

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Nov 05, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

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.

Apr 24, 2020

GeneDx

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

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)

Mar 02, 2018

Eurofins Ntd Llc (ga)

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

May 01, 2025

CeGaT Center for Human Genetics Tuebingen

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

FGFR3: PS2:Very Strong, PS4, PM2, PS3:Supporting

Nov 25, 2024

ARUP Laboratories, Molecular Genetics and Genomics, ARUP Laboratories

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

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.

May 25, 2020

Revvity Omics, Revvity

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

See cases Pathogenic:1

Aug 20, 2021

Institute Of Reproduction And Development, Obstetrics and Gynecology Hospital, Fudan University

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: research

FGFR3-related disorder Pathogenic:1

Mar 12, 2024

PreventionGenetics, part of Exact Sciences

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: clinical testing

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.

Achondroplasia Pathogenic:1

Sep 10, 2025

Genomic Medicine Center of Excellence, King Faisal Specialist Hospital and Research Centre

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.18
BayesDel_addAF	Pathogenic	0.40	D
BayesDel_noAF	Pathogenic	0.34
CADD	Uncertain	24
DANN	Uncertain	0.99
DEOGEN2	Pathogenic	0.93	D
Eigen	Uncertain	0.26
Eigen_PC	Benign	0.084
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Uncertain	0.96	D
M_CAP	Pathogenic	0.67	D
MetaRNN	Pathogenic	0.98	D
MetaSVM	Uncertain	0.73	D
MutationAssessor	Uncertain	2.4	M
PhyloP100		3.5
PrimateAI	Uncertain	0.70	T
PROVEAN	Pathogenic	-6.0	D
REVEL	Pathogenic	0.80
Sift	Uncertain	0.0030	D
Sift4G	Uncertain	0.039	D
Polyphen		0.99	D
Vest4		0.86
MutPred		0.85		Gain of sheet (P = 0.0344)
MVP		0.96
MPC		0.99
ClinPred		0.99	D
GERP RS		1.9
Varity_R		0.62
gMVP		0.77
Mutation Taster		=6/94	disease causing (ClinVar)

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.020		Details are displayed if max score is > 0.2

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

Other links and lift over

dbSNP: rs121913485; hg19: chr4-1806099; COSMIC: COSV53390174; COSMIC: COSV53390174;