chr4-1793986-G-A

Position:

• chr4-1793986-G-A

Variant summary

Our verdict is Uncertain significance. Variant got 0 ACMG points: 2P and 2B. PM2 BP4_Moderate

The NM_000142.5(FGFR3):​c.52G>A​(p.Ala18Thr) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000115 in 1,385,574 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 13/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: 𝑓 0.0000066 (0 hom., cov: 34)
  • Exomes 𝑓: 0.000012 (0 hom.)
• Consequence: FGFR3 NM_000142.5 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: -0.350

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 0 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.24532372).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
FGFR3	NM_000142.5	c.52G>A	p.Ala18Thr	missense_variant	2/18	ENST00000440486.8

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
FGFR3	ENST00000440486.8	c.52G>A	p.Ala18Thr	missense_variant	2/18	5	NM_000142.5	P4

Frequencies

GnomAD3 genomes AF: 0.00000658 AC: 1 AN: 152076 Hom.: 0 Cov.: 34

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.0000147

Gnomad OTH AF: 0.00

GnomAD4 exome AF: 0.0000122 AC: 15 AN: 1233498 Hom.: 0 Cov.: 29 AF XY: 0.0000133 AC XY: 8 AN XY: 602708

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.0000141

Gnomad4 OTH exome AF: 0.0000203

GnomAD4 genome AF: 0.00000658 AC: 1 AN: 152076 Hom.: 0 Cov.: 34 AF XY: 0.00 AC XY: 0 AN XY: 74302

Gnomad4 AFR AF: 0.00

Gnomad4 AMR AF: 0.00

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.0000147

Gnomad4 OTH AF: 0.00

Bravo AF: 0.0000151

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

Invitae

Nov 18, 2023

This sequence change replaces alanine, which is neutral and non-polar, with threonine, which is neutral and polar, at codon 18 of the FGFR3 protein (p.Ala18Thr). This variant is not present in population databases (gnomAD no frequency). This variant has not been reported in the literature in individuals affected with FGFR3-related conditions. Algorithms developed to predict the effect of missense changes on protein structure and function output the following: SIFT: "Not Available"; PolyPhen-2: "Not Available"; Align-GVGD: "Not Available". The threonine amino acid residue is found in multiple mammalian species, which suggests that this missense change does not adversely affect protein function. 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. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.073
BayesDel_addAF	Benign	-0.16	T
BayesDel_noAF	Benign	-0.47
CADD	Benign	11
DANN	Uncertain	0.98
DEOGEN2	Uncertain	0.45	T;T;.;.;T;.
Eigen	Benign	-1.1
Eigen_PC	Benign	-1.1
FATHMM_MKL	Benign	0.023	N
LIST_S2	Benign	0.71	T;T;T;T;T;.
M_CAP	Pathogenic	0.91	D
MetaRNN	Benign	0.25	T;T;T;T;T;T
MetaSVM	Benign	-0.90	T
MutationAssessor	Benign	0.0	N;.;N;N;.;N
MutationTaster	Benign	1.0	N;N;N;N;N;N
PrimateAI	Uncertain	0.78	T
PROVEAN	Benign	-0.44	N;N;N;N;.;N
REVEL	Benign	0.21
Sift	Benign	0.11	T;D;T;D;.;D
Sift4G	Benign	0.42	T;T;T;T;T;T
Polyphen		0.0	B;B;B;B;.;B
Vest4		0.056
MutPred		0.37		Gain of sheet (P = 0.0011);Gain of sheet (P = 0.0011);Gain of sheet (P = 0.0011);Gain of sheet (P = 0.0011);Gain of sheet (P = 0.0011);Gain of sheet (P = 0.0011);
MVP		0.74
MPC		0.27
ClinPred		0.042	T
GERP RS		0.90
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		2.6
Varity_R		0.031
gMVP		0.24

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: rs908992323; hg19: chr4-1795713;