chr4-1799344-G-C

Variant names:

• chr4-1799344-G-C
• rs369232922
• NM_000142.5:c.200G>C

Variant summary

Our verdict is Likely benign. The variant received -2 ACMG points: 2P and 4B. PM2 BP4_Strong

The NM_000142.5(FGFR3):​c.200G>C​(p.Gly67Ala) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000685 in 1,460,238 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 16/22 in silico tools predict a benign 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. G67D) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: FGFR3 NM_000142.5 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 0.323
• Publications: 2 publications found

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 Gene-Disease associations (from GenCC):

• achondroplasia

  Inheritance: AD Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: G2P, ClinGen, Genomics England PanelApp, Orphanet, Ambry Genetics, Labcorp Genetics (formerly Invitae)
• Crouzon syndrome-acanthosis nigricans syndrome

  Inheritance: AD Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: G2P, Ambry Genetics, Orphanet, Genomics England PanelApp, Labcorp Genetics (formerly Invitae), PanelApp Australia, ClinGen
• hypochondroplasia

  Inheritance: AD Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Ambry Genetics, G2P, ClinGen, Labcorp Genetics (formerly Invitae), Orphanet
• lacrimoauriculodentodigital syndrome 2

  Inheritance: AD Classification: DEFINITIVE Submitted by: G2P
• Muenke syndrome

  Inheritance: AD Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Orphanet, Ambry Genetics, PanelApp Australia, Labcorp Genetics (formerly Invitae), Genomics England PanelApp, ClinGen, G2P
• thanatophoric dysplasia type 1

  Inheritance: AD Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: G2P, Ambry Genetics, Genomics England PanelApp, Orphanet, ClinGen
• thanatophoric dysplasia type 2

  Inheritance: AD Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Orphanet, ClinGen, Genomics England PanelApp, G2P, Labcorp Genetics (formerly Invitae)
• camptodactyly-tall stature-scoliosis-hearing loss syndrome

  Inheritance: AR, AD, SD Classification: DEFINITIVE, STRONG, MODERATE, SUPPORTIVE, LIMITED Submitted by: Ambry Genetics, G2P, Orphanet, Labcorp Genetics (formerly Invitae), ClinGen
• severe achondroplasia-developmental delay-acanthosis nigricans syndrome

  Inheritance: AD Classification: STRONG, MODERATE, SUPPORTIVE Submitted by: Orphanet, Labcorp Genetics (formerly Invitae), ClinGen
• isolated brachycephaly

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• isolated plagiocephaly

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• LADD syndrome

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• LADD syndrome 1

  Inheritance: AD Classification: LIMITED Submitted by: Labcorp Genetics (formerly Invitae)

ACMG classification

Our verdict: Likely_benign. The variant received -2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.044391215).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
FGFR3	NM_000142.5	c.200G>C	p.Gly67Ala	missense_variant	Exon 3 of 18	ENST00000440486.8	NP_000133.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
FGFR3	ENST00000440486.8	c.200G>C	p.Gly67Ala	missense_variant	Exon 3 of 18	5	NM_000142.5	ENSP00000414914.2

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 6.85e-7 AC: 1 AN: 1460238 Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0 AN XY: 726406

African (AFR) AF: 0.00 AC: 0 AN: 33476

American (AMR) AF: 0.00 AC: 0 AN: 44700

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26106

East Asian (EAS) AF: 0.00 AC: 0 AN: 39696

South Asian (SAS) AF: 0.00 AC: 0 AN: 86238

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 52052

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5744

European-Non Finnish (NFE) AF: 8.99e-7 AC: 1 AN: 1111864

Other (OTH) AF: 0.00 AC: 0 AN: 60362

GnomAD4 genome Cov.: 33

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Thanatophoric dysplasia, type 2 Uncertain:1

Aug 01, 2020

Foundation for Research in Genetics and Endocrinology, FRIGE's Institute of Human Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

A heterozygous missense variation in exon 3 of the FGFR3 gene that results in the amino acid substitution of Alanine for Glycine at codon 67 was detected. The observed variant c.200G>C (p.Gly67Ala) has not been reported in the 1000 genomes and gnomAD databases. The in silico prediction of the variant is benign by PolyPhen-2 (HumDiv), SIFT and MutationTaster2. The reference codon is conserved across mammals. In summary, the variant meets our criteria to be classified as a variant of uncertain significance.

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.074
BayesDel_addAF	Benign	-0.32	T
BayesDel_noAF	Benign	-0.69
CADD	Benign	3.0
DANN	Benign	0.90
DEOGEN2	Benign	0.36	T;T;.;.;T;.
Eigen	Benign	-1.2
Eigen_PC	Benign	-1.2
FATHMM_MKL	Benign	0.10	N
LIST_S2	Benign	0.80	T;T;T;T;T;.
M_CAP	Benign	0.048	D
MetaRNN	Benign	0.044	T;T;T;T;T;T
MetaSVM	Benign	-1.0	T
MutationAssessor	Benign	-0.44	N;.;N;N;.;N
PhyloP100		0.32
PrimateAI	Benign	0.47	T
PROVEAN	Benign	0.41	N;N;N;N;.;N
REVEL	Benign	0.015
Sift	Benign	1.0	T;T;T;T;.;T
Sift4G	Benign	0.85	T;T;T;T;T;T
Vest4		0.18
ClinPred		0.080	T
GERP RS		-0.0076
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.1
Varity_R		0.046
gMVP		0.24
Mutation Taster		=95/5	polymorphism

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

Other links and lift over

dbSNP: rs369232922; hg19: chr4-1801071; COSMIC: COSV105835183;