NM_033163.5:c.686C>T

Variant names:

• chr10-101770378-G-A
• rs137852664
• NM_033163.5:c.686C>T

Variant summary

Our verdict is Benign. Variant got -9 ACMG points: 0P and 9B. BP4_Strong BS1_Supporting BS2

The NM_033163.5(FGF8):​c.686C>T​(p.Thr229Met) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000161 in 1,603,406 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

• Frequency:
  • Genomes: 𝑓 0.00018 (0 hom., cov: 33)
  • Exomes 𝑓: 0.00016 (0 hom.)
• Consequence: FGF8 NM_033163.5 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:4 B:1
• Conservation: PhyloP100: 2.80

Genes affected

FGF8 (HGNC:3686): (fibroblast growth factor 8) The protein encoded by this gene is a member of the fibroblast growth factor (FGF) family. FGF family members possess broad mitogenic and cell survival activities, and are involved in a variety of biological processes, including embryonic development, cell growth, morphogenesis, tissue repair, tumor growth and invasion. This protein is known to be a factor that supports androgen and anchorage independent growth of mammary tumor cells. Overexpression of this gene has been shown to increase tumor growth and angiogensis. The adult expression of this gene is restricted to testes and ovaries. Temporal and spatial pattern of this gene expression suggests its function as an embryonic epithelial factor. Studies of the mouse and chick homologs revealed roles in midbrain and limb development, organogenesis, embryo gastrulation and left-right axis determination. The alternative splicing of this gene results in four transcript variants. [provided by RefSeq, Jul 2008]

LOC105378457 (HGNC:):

ACMG classification

Verdict is Benign. Variant got -9 ACMG points.

• BP4: Computational evidence support a benign effect (MetaRNN=0.050103843).
• BS1: Variant frequency is greater than expected in population sas. gnomad4 allele frequency = 0.000177 (27/152312) while in subpopulation SAS AF= 0.00207 (10/4826). AF 95% confidence interval is 0.00112. There are 0 homozygotes in gnomad4. There are 15 alleles in male gnomad4 subpopulation. Median coverage is 33. This position pass quality control queck. Existence of Clinvar submissions makes me limit the strength of this signal to Supporting
• BS2: High AC in GnomAd4 at 27 AD,Digenic gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
FGF8	NM_033163.5	c.686C>T	p.Thr229Met	missense_variant	Exon 6 of 6	ENST00000320185.7	NP_149353.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
FGF8	ENST00000320185.7	c.686C>T	p.Thr229Met	missense_variant	Exon 6 of 6	1	NM_033163.5	ENSP00000321797.2

Frequencies

GnomAD3 genomes AF: 0.000177 AC: 27 AN: 152194 Hom.: 0 Cov.: 33

Gnomad AFR AF: 0.0000241

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.000579

Gnomad SAS AF: 0.00207

Gnomad FIN AF: 0.000188

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.000162

Gnomad OTH AF: 0.00

GnomAD3 exomes AF: 0.000260 AC: 59 AN: 226744 Hom.: 0 AF XY: 0.000284 AC XY: 35 AN XY: 123146

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.000891

Gnomad SAS exome AF: 0.00129

Gnomad FIN exome AF: 0.000105

Gnomad NFE exome AF: 0.0000393

Gnomad OTH exome AF: 0.000180

GnomAD4 exome AF: 0.000159 AC: 231 AN: 1451094 Hom.: 0 Cov.: 32 AF XY: 0.000175 AC XY: 126 AN XY: 720990

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.0000470

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.000535

Gnomad4 SAS exome AF: 0.00131

Gnomad4 FIN exome AF: 0.000134

Gnomad4 NFE exome AF: 0.0000686

Gnomad4 OTH exome AF: 0.000234

GnomAD4 genome AF: 0.000177 AC: 27 AN: 152312 Hom.: 0 Cov.: 33 AF XY: 0.000201 AC XY: 15 AN XY: 74464

Gnomad4 AFR AF: 0.0000240

Gnomad4 AMR AF: 0.00

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.000580

Gnomad4 SAS AF: 0.00207

Gnomad4 FIN AF: 0.000188

Gnomad4 NFE AF: 0.000162

Gnomad4 OTH AF: 0.00

Alfa AF: 0.000355 Hom.: 0

Bravo AF: 0.000121

ESP6500AA AF: 0.00 AC: 0

ESP6500EA AF: 0.000116 AC: 1

ExAC AF: 0.000248 AC: 30

Asia WGS AF: 0.00115 AC: 4 AN: 3478

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:4 Benign:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

not provided Uncertain:2 Benign:1

Dec 01, 2022

CeGaT Center for Human Genetics Tuebingen

Significance: Benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

FGF8: BS1, BS2 -

Oct 04, 2023

GeneDx

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

In silico analysis supports that this missense variant does not alter protein structure/function; Published functional studies demonstrate a possible damaging effect on protein function, but the biological significance of the findings is not established (Falardeau et al., 2008); This variant is associated with the following publications: (PMID: 21664428, 21976454, 21045958, 19621416, 28645738, 18596921) -

Oct 25, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces threonine, which is neutral and polar, with methionine, which is neutral and non-polar, at codon 229 of the FGF8 protein (p.Thr229Met). This variant is present in population databases (rs137852664, gnomAD 0.1%), and has an allele count higher than expected for a pathogenic variant. This missense change has been observed in individual(s) with idiopathic hypogonadotropic hypogonadism (PMID: 18596921). ClinVar contains an entry for this variant (Variation ID: 9126). An algorithm developed to predict the effect of missense changes on protein structure and function (PolyPhen-2) suggests that this variant is likely to be disruptive. 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. -

Hypogonadotropic hypogonadism 6 with or without anosmia Uncertain:1

Jan 01, 2010

OMIM

Significance: Uncertain significance

Review Status: no assertion criteria provided

Collection Method: literature only

- -

Holoprosencephaly 1 Uncertain:1

May 28, 2019

Mendelics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.20
BayesDel_addAF	Benign	-0.15	T
BayesDel_noAF	Uncertain	-0.040
CADD	Pathogenic	28
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.65	.;D;.;.;.
Eigen	Uncertain	0.26
Eigen_PC	Uncertain	0.26
FATHMM_MKL	Uncertain	0.89	D
LIST_S2	Uncertain	0.91	D;D;D;D;D
M_CAP	Uncertain	0.26	D
MetaRNN	Benign	0.050	T;T;T;T;T
MetaSVM	Benign	-0.44	T
MutationAssessor	Benign	0.0	.;N;.;.;.
PrimateAI	Uncertain	0.69	T
PROVEAN	Benign	-2.3	.;N;N;N;N
REVEL	Uncertain	0.53
Sift	Benign	0.052	.;T;D;D;T
Sift4G	Uncertain	0.018	D;D;D;D;D
Polyphen		0.99, 1.0, 1.0	.;D;D;D;D
Vest4		0.36
MVP		0.87
MPC		1.8
ClinPred		0.099	T
GERP RS		3.8
Varity_R		0.079
gMVP		0.19

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: rs137852664; hg19: chr10-103530135; COSMIC: COSV60142881;