rs121913103

chr4-1807262-A-Cchr4-1807262-A-Gchr4-1807262-A-T

Variant summary

Our verdict is Uncertain significance. Variant got 3 ACMG points: 4P and 1B. PM2 PP5_Moderate BP4

The NM_000142.5(FGFR3):c.2421A>C(p.Ter807CysextTer101) variant causes a stop lost change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Pathogenic (★).

• Frequency: Genomes: not found (cov: 33)
• Consequence: FGFR3 NM_000142.5 stop_lost
• Clinical Significance: Pathogenic criteria provided, single submitter P:2 O:1
• Conservation: PhyloP100: 3.42

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]

ACMG classification

Verdict is Uncertain_significance. Variant got 3 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 4-1807262-A-C is Pathogenic according to our data. Variant chr4-1807262-A-C is described in ClinVar as [Pathogenic]. Clinvar id is 65563.Status of the report is criteria_provided_single_submitter, 1 stars. Variant chr4-1807262-A-C is described in Lovd as [Pathogenic].
• BP4: Computational evidence support a benign effect (MetaRNN=0.3079421).. Strength limited to SUPPORTING due to the PP5.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
FGFR3	NM_000142.5	c.2421A>C	p.Ter807CysextTer101	stop_lost	18/18	ENST00000440486.8

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
FGFR3	ENST00000440486.8	c.2421A>C	p.Ter807CysextTer101	stop_lost	18/18	5	NM_000142.5	P4

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 35

GnomAD4 genome Cov.: 33

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:2 Other:1

Revision: criteria provided, single submitter

Submissions by phenotype

Thanatophoric dysplasia type 1 Pathogenic:1 Other:1

Pathogenic, no assertion criteria provided	clinical testing	Molecular Genetics Laboratory, BC Children's and BC Women's Hospitals	May 08, 2019	- -
not provided, no classification provided	literature only	GeneReviews	-	- -

not provided Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

GeneDx

Oct 25, 2022

Variant results in substitution of the termination codon, leading to protein extension by 101 amino acids; Several different variants resulting in similar protein extensions have been reported in the Human Gene Mutation Database associated with thanatophoric dysplasia (HGMD), and have apparently similar functional consequences on protein stability and/or processing(Bonaventure et al., 2007; Gibbs et al., 2007); Not observed in large population cohorts (gnomAD); This variant is associated with the following publications: (PMID: 10425034, 25728633, 17509076, 17320202) -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.21	D
BayesDel_noAF	Uncertain	0.070
Cadd	Benign	17
Dann	Benign	0.76
DEOGEN2	Benign	0.22	T
Eigen	Pathogenic	0.83
Eigen_PC	Uncertain	0.62
FATHMM_MKL	Uncertain	0.92	D
LIST_S2	Benign	0.32	T
MetaRNN	Benign	0.31	T
MetaSVM	Benign	-1.0	T
MutationTaster	Benign	1.0	N;N;N;N;N;N
PROVEAN	Benign	0.13	N
REVEL	Uncertain	0.46
Sift	Pathogenic	0.0	D
Polyphen		0.56	P
Vest4		0.15
MutPred		0.48		Loss of methylation at K785 (P = 0.0069);
MVP		0.84
ClinPred		0.88	D
GERP RS		4.6

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: rs121913103; hg19: chr4-1808989;