4-1806076-G-T

Variant summary

Our verdict is Likely pathogenic. Variant got 8 ACMG points: 8P and 0B. PM2 PM5 PP3_Strong

The NM_000142.5(FGFR3):c.1862G>T(p.Arg621Leu) variant causes a missense change involving the alteration of a 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 (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R621C) has been classified as Likely pathogenic.

• Frequency: Genomes: not found (cov: 34)
• Consequence: FGFR3 NM_000142.5 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 9.65

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 Likely_pathogenic. Variant got 8 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr4-1806075-C-T is described in ClinVar as [Likely_pathogenic]. Clinvar id is 1680110.Status of the report is criteria_provided_single_submitter, 1 stars.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.995

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
FGFR3	NM_000142.5	c.1862G>T	p.Arg621Leu	missense_variant	14/18	ENST00000440486.8

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
FGFR3	ENST00000440486.8	c.1862G>T	p.Arg621Leu	missense_variant	14/18	5	NM_000142.5	P4

Frequencies

GnomAD3 genomes Cov.: 34

GnomAD4 exome Cov.: 35

GnomAD4 genome Cov.: 34

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

not provided Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

GeneDx

Nov 12, 2020

Not observed in large population cohorts (Lek et al., 2016); In silico analysis, which includes protein predictors and evolutionary conservation, supports a deleterious effect; Has not been previously published as pathogenic or benign to our knowledge -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	1.0
BayesDel_addAF	Pathogenic	0.45	D
BayesDel_noAF	Pathogenic	0.41
Cadd	Pathogenic	32
Dann	Uncertain	1.0
DEOGEN2	Pathogenic	0.94	D;D;.;.;.
Eigen	Pathogenic	0.70
Eigen_PC	Uncertain	0.60
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.97	D;D;D;D;.
M_CAP	Pathogenic	0.83	D
MetaRNN	Pathogenic	0.99	D;D;D;D;D
MetaSVM	Pathogenic	0.81	D
MutationAssessor	Uncertain	2.4	M;.;.;.;.
MutationTaster	Benign	1.0	D;D;D;D;D;D
PrimateAI	Pathogenic	0.92	D
PROVEAN	Pathogenic	-6.1	D;D;D;D;D
REVEL	Pathogenic	0.91
Sift	Pathogenic	0.0	D;D;D;D;D
Sift4G	Pathogenic	0.0	D;D;D;D;D
Polyphen		1.0	D;D;D;D;D
Vest4		0.97
MutPred		0.93		Loss of catalytic residue at R621 (P = 0.0811);.;.;.;.;
MVP		0.94
MPC		2.5
ClinPred		1.0	D
GERP RS		4.2
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.96
gMVP		0.86

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

No publications associated with this variant yet.

Other links and lift over

hg19: chr4-1807803;