4-1804384-T-G

Position:

• chr4-1804384-T-G

Variant summary

Our verdict is Likely pathogenic. Variant got 6 ACMG points: 6P and 0B. PM1 PM2 PP3_Moderate

The NM_000142.5(FGFR3):​c.1130T>G​(p.Leu377Arg) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000205 in 1,460,790 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 Uncertain significance (★).

• Frequency:
  • Genomes: not found (cov: 34)
  • Exomes 𝑓: 0.0000021 (0 hom.)
• Consequence: FGFR3 NM_000142.5 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 7.48

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 (HGNC:):

ACMG classification

Verdict is Likely_pathogenic. Variant got 6 ACMG points.

• PM1: In a transmembrane_region Helical (size 20) in uniprot entity FGFR3_HUMAN there are 7 pathogenic changes around while only 3 benign (70%) in NM_000142.5
• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.937

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
FGFR3	NM_000142.5	c.1130T>G	p.Leu377Arg	missense_variant	9/18	ENST00000440486.8	NP_000133.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
FGFR3	ENST00000440486.8	c.1130T>G	p.Leu377Arg	missense_variant	9/18	5	NM_000142.5	ENSP00000414914.2

Frequencies

GnomAD3 genomes Cov.: 34

GnomAD3 exomes AF: 0.00000799 AC: 2 AN: 250364 Hom.: 0 AF XY: 0.00000739 AC XY: 1 AN XY: 135386

Gnomad AFR exome AF: 0.0000616

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.0000327

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000205 AC: 3 AN: 1460790 Hom.: 0 Cov.: 36 AF XY: 0.00000275 AC XY: 2 AN XY: 726712

Gnomad4 AFR exome AF: 0.0000299

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.0000116

Gnomad4 FIN exome AF: 0.0000189

Gnomad4 NFE exome AF: 0.00

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 34

Bravo AF: 0.00000378

ExAC AF: 0.00000824 AC: 1

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

Labcorp Genetics (formerly Invitae), Labcorp

Jan 12, 2022

In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. Algorithms developed to predict the effect of missense changes on protein structure and function are either unavailable or do not agree on the potential impact of this missense change (SIFT: "Deleterious"; PolyPhen-2: "Probably Damaging"; Align-GVGD: "Class C0"). This missense change has been observed in individual(s) with clinical features of FGFR3-related conditions, however it's commonly seen with the pathogenic variant p.Gly380Arg (PMID: 16411219, 29593476). This variant is present in population databases (rs267606809, gnomAD 0.007%). This sequence change replaces leucine, which is neutral and non-polar, with arginine, which is basic and polar, at codon 377 of the FGFR3 protein (p.Leu377Arg). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Uncertain	0.39
BayesDel_addAF	Pathogenic	0.29	D
BayesDel_noAF	Pathogenic	0.36
CADD	Uncertain	25
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.92	D;T;.
Eigen	Uncertain	0.64
Eigen_PC	Uncertain	0.58
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.91	D;D;D
M_CAP	Pathogenic	0.77	D
MetaRNN	Pathogenic	0.94	D;D;D
MetaSVM	Pathogenic	0.81	D
MutationAssessor	Benign	1.8	L;.;.
PrimateAI	Uncertain	0.58	T
PROVEAN	Uncertain	-3.0	D;D;D
REVEL	Pathogenic	0.93
Sift	Uncertain	0.0030	D;D;D
Sift4G	Benign	0.13	T;T;T
Polyphen		0.90	P;D;D
Vest4		0.89
MutPred		0.77		Loss of sheet (P = 0.0817);Loss of sheet (P = 0.0817);.;
MVP		0.98
MPC		1.2
ClinPred		0.87	D
GERP RS		4.7
Varity_R		0.92
gMVP		0.90

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: rs267606809; hg19: chr4-1806111;