chr10-101771509-G-A

Position:

• chr10-101771509-G-A

Variant summary

Our verdict is Uncertain significance. Variant got 1 ACMG points: 5P and 4B. PP3_Strong PP5 BS2

The NM_033163.5(FGF8):​c.398C>T​(p.Thr133Met) variant causes a missense change. The variant allele was found at a frequency of 0.00000547 in 1,461,866 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 Conflicting classifications of pathogenicity (no stars).

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.0000055 (0 hom.)
• Consequence: FGF8 NM_033163.5 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:1 U:1
• Conservation: PhyloP100: 5.75

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 Uncertain_significance. Variant got 1 ACMG points.

• PP3: MetaRNN computational evidence supports a deleterious effect, 0.966
• PP5: Variant 10-101771509-G-A is Pathogenic according to our data. Variant chr10-101771509-G-A is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 545458.We mark this variant Likely_pathogenic, oryginal submissions are: {Likely_pathogenic=1, Uncertain_significance=1}.
• BS2: High AC in GnomAdExome4 at 8 AD,Digenic gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
FGF8	NM_033163.5	c.398C>T	p.Thr133Met	missense_variant	5/6	ENST00000320185.7	NP_149353.1
LOC105378457	XR_007062268.1	n.290G>A		non_coding_transcript_exon_variant	3/3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
FGF8	ENST00000320185.7	c.398C>T	p.Thr133Met	missense_variant	5/6	1	NM_033163.5	ENSP00000321797	A2

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD3 exomes AF: 0.00000795 AC: 2 AN: 251482 Hom.: 0 AF XY: 0.00000736 AC XY: 1 AN XY: 135914

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00000879

Gnomad OTH exome AF: 0.000163

GnomAD4 exome AF: 0.00000547 AC: 8 AN: 1461866 Hom.: 0 Cov.: 31 AF XY: 0.00000688 AC XY: 5 AN XY: 727240

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: 0.0000187

Gnomad4 NFE exome AF: 0.00000540

Gnomad4 OTH exome AF: 0.0000166

GnomAD4 genome Cov.: 33

Alfa AF: 0.000223 Hom.: 0

EpiCase AF: 0.0000545

EpiControl AF: 0.00

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:1 Uncertain:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Holoprosencephaly sequence Pathogenic:1

Likely pathogenic, criteria provided, single submitter

research

Muenke lab, National Institutes of Health

Apr 19, 2018

Consistent clinical findings. Consanguinity confirmed. Meets experimental and ACMG criteria: PS3;PM2;PP2/PP3. -

not provided Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

GeneDx

Aug 04, 2022

Not observed at significant frequency in large population cohorts (gnomAD); Published functional studies suggest a damaging effect as in vivo functional studies show that p.T133M results in partial loss of function with an altered developmental phenotype (Hong et al., 2018); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; Observed in the homozygous state in a patient with holoprosencephaly (Roessler et al., 2018, Hong et al., 2018); This variant is associated with the following publications: (PMID: 29992659, 29584859) -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.90
BayesDel_addAF	Pathogenic	0.43	D
BayesDel_noAF	Pathogenic	0.39
CADD	Pathogenic	32
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.96	.;D;.;.;.
Eigen	Uncertain	0.62
Eigen_PC	Uncertain	0.49
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Uncertain	0.95	D;D;D;D;D
M_CAP	Pathogenic	0.40	D
MetaRNN	Pathogenic	0.97	D;D;D;D;D
MetaSVM	Pathogenic	0.91	D
MutationAssessor	Uncertain	2.8	.;M;.;.;.
MutationTaster	Benign	1.0	D;D;D;D
PrimateAI	Uncertain	0.74	T
PROVEAN	Uncertain	-3.0	.;D;D;D;D
REVEL	Pathogenic	0.84
Sift	Uncertain	0.0010	.;D;D;D;D
Sift4G	Uncertain	0.0030	D;D;D;D;D
Polyphen		1.0	.;D;D;D;D
Vest4		0.82
MutPred		0.87		.;Gain of MoRF binding (P = 0.0809);.;.;.;
MVP		0.94
MPC		2.0
ClinPred		0.98	D
GERP RS		4.7
Varity_R		0.83
gMVP		0.85

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: rs61730334; hg19: chr10-103531266;