chr4-1794011-G-A

Position:

• chr4-1794011-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.77G>A​(p.Gly26Glu) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000237 in 1,264,950 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 14/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: not found (cov: 34)
  • Exomes 𝑓: 0.0000024 (0 hom.)
• Consequence: FGFR3 NM_000142.5 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: -0.439

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=0.16582674).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
FGFR3	NM_000142.5	c.77G>A	p.Gly26Glu	missense_variant	2/18	ENST00000440486.8	NP_000133.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
FGFR3	ENST00000440486.8	c.77G>A	p.Gly26Glu	missense_variant	2/18	5	NM_000142.5	ENSP00000414914	P4

Frequencies

GnomAD3 genomes Cov.: 34

GnomAD4 exome AF: 0.00000237 AC: 3 AN: 1264950 Hom.: 0 Cov.: 29 AF XY: 0.00000483 AC XY: 3 AN XY: 620812

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: 0.00000298

Gnomad4 OTH exome AF: 0.00

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

Labcorp Genetics (formerly Invitae), Labcorp

Aug 06, 2017

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 (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be tolerated, but these predictions have not been confirmed by published functional studies and their clinical significance is uncertain. This variant has not been reported in the literature in individuals with FGFR3-related disease. While this variant is not present in population databases, the frequency information is unreliable, as metrics indicate poor data quality at this position in the ExAC database. This sequence change replaces glycine with glutamic acid at codon 26 of the FGFR3 protein (p.Gly26Glu). The glycine residue is weakly conserved and there is a moderate physicochemical difference between glycine and glutamic acid. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.070
BayesDel_addAF	Benign	-0.14	T
BayesDel_noAF	Benign	-0.44
CADD	Benign	16
DANN	Benign	0.93
DEOGEN2	Benign	0.36	T;T;.;.;T;.
Eigen	Benign	-0.99
Eigen_PC	Benign	-1.1
FATHMM_MKL	Benign	0.056	N
LIST_S2	Uncertain	0.86	D;D;D;D;D;.
M_CAP	Pathogenic	0.94	D
MetaRNN	Benign	0.17	T;T;T;T;T;T
MetaSVM	Benign	-0.72	T
MutationAssessor	Benign	0.69	N;.;N;N;.;N
MutationTaster	Benign	1.0	N;N;N;N;N;N
PrimateAI	Uncertain	0.76	T
PROVEAN	Benign	0.46	N;N;N;N;.;N
REVEL	Benign	0.22
Sift	Benign	1.0	T;T;T;T;.;T
Sift4G	Benign	1.0	T;T;T;T;T;T
Polyphen		0.12	B;D;P;D;.;D
Vest4		0.30
MutPred		0.15		Gain of solvent accessibility (P = 0.0374);Gain of solvent accessibility (P = 0.0374);Gain of solvent accessibility (P = 0.0374);Gain of solvent accessibility (P = 0.0374);Gain of solvent accessibility (P = 0.0374);Gain of solvent accessibility (P = 0.0374);
MVP		0.81
MPC		0.42
ClinPred		0.12	T
GERP RS		-0.011
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.1
Varity_R		0.027
gMVP		0.28

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: rs1221876688; hg19: chr4-1795738;