10-101770490-AGCCCTTGCGGGGCCG-A

Variant summary

Our verdict is Pathogenic. Variant got 12 ACMG points: 12P and 0B. PM2 PM4 PP5_Very_Strong

The NM_033163.5(FGF8):c.559_573del(p.Arg187_Gly191del) variant causes a inframe deletion change. The variant allele was found at a frequency of 0.000000684 in 1,461,376 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Pathogenic (★★).

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: FGF8 NM_033163.5 inframe_deletion
• Clinical Significance: Pathogenic criteria provided, multiple submitters, no conflicts P:2
• Conservation: PhyloP100: 5.81

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 Pathogenic. Variant got 12 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PM4: Nonframeshift variant in NON repetitive region in NM_033163.5.
• PP5: Variant 10-101770490-AGCCCTTGCGGGGCCG-A is Pathogenic according to our data. Variant chr10-101770490-AGCCCTTGCGGGGCCG-A is described in ClinVar as [Pathogenic]. Clinvar id is 545457.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
FGF8	NM_033163.5	c.559_573del	p.Arg187_Gly191del	inframe_deletion	6/6	ENST00000320185.7
LOC105378457	XR_007062268.1	n.138-55_138-41del		intron_variant, non_coding_transcript_variant

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
FGF8	ENST00000320185.7	c.559_573del	p.Arg187_Gly191del	inframe_deletion	6/6	1	NM_033163.5	A2

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461376 Hom.: 0 AF XY: 0.00 AC XY: 0 AN XY: 727030

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: 8.99e-7

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 33

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Holoprosencephaly sequence Pathogenic:1

Pathogenic, criteria provided, single submitter

research

Muenke lab, National Institutes of Health

Apr 18, 2018

Family history of similarly affected female sibs with evidence of digenic inheritance of a paternal LOF allele in FGF8 and a maternal LOF allele in FGFR1. Established gene to gene interactions in animal models. This FGF8 variation is supported by experimental data and ACMG criteria: PS3;PM1/PM2/PM4;PP1. -

not provided Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

GeneDx

Jul 27, 2021

Identified in siblings with holoprosencephaly in published literature (Hong et al., 2016); Published Zebrafish model showed a complete loss of biological activity (Hong et al., 2016); In-frame deletion of 5 amino acids in a non-repeat region; Not observed at significant frequency in large population cohorts (Lek et al., 2016); In silico analysis supports a deleterious effect on protein structure/function; This variant is associated with the following publications: (PMID: 26931467) -

Computational scores

Source: dbNSFP v4.3

Splicing

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

LitVar

Other links and lift over

dbSNP: rs1554834321; hg19: chr10-103530247;