rs1554928905

Positions:

• chr10-121517390-CC-TT

Variant summary

Our verdict is Likely pathogenic. Variant got 8 ACMG points: 8P and 0B. PM1 PM2 PM5 PP2 PP3

The ENST00000358487.10(FGFR2):​c.1012_1013delinsAA​(p.Gly338Lys) variant causes a missense change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. 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. G338E) has been classified as Likely pathogenic.

• Frequency: Genomes: not found (cov: 32)
• Consequence: FGFR2 ENST00000358487.10 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 7.85

Genes affected

FGFR2 (HGNC:3689): (fibroblast growth factor receptor 2) The protein encoded by this gene is a member of the fibroblast growth factor receptor family, where amino acid sequence is highly conserved between members and throughout evolution. FGFR family members differ from one another in their ligand affinities and tissue distribution. A full-length representative protein consists 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 is a high-affinity receptor for acidic, basic and/or keratinocyte growth factor, depending on the isoform. Mutations in this gene are associated with Crouzon syndrome, Pfeiffer syndrome, Craniosynostosis, Apert syndrome, Jackson-Weiss syndrome, Beare-Stevenson cutis gyrata syndrome, Saethre-Chotzen syndrome, and syndromic craniosynostosis. Multiple alternatively spliced transcript variants encoding different isoforms have been noted for this gene. [provided by RefSeq, Jan 2009]

ACMG classification

Verdict is Likely_pathogenic. Variant got 8 ACMG points.

• PM1: In a hotspot region, there are 7 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 1 benign, 6 uncertain in ENST00000358487.10
• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr10-121517390-C-T is described in ClinVar as [Likely_pathogenic]. Clinvar id is 374817.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
• PP2: Missense variant in gene, where missense usually causes diseases (based on misZ statistic), FGFR2. . Gene score misZ 2.402 (greater than the threshold 3.09). Trascript score misZ 4.4365 (greater than threshold 3.09). GenCC has associacion of gene with Pfeiffer syndrome type 3, Antley-Bixler syndrome, Pfeiffer syndrome type 2, Saethre-Chotzen syndrome, Beare-Stevenson cutis gyrata syndrome, Crouzon syndrome, Jackson-Weiss syndrome, Pfeiffer syndrome type 1, LADD syndrome 1, Pfeiffer syndrome, bent bone dysplasia syndrome 1, Antley-Bixler syndrome without genital anomalies or disordered steroidogenesis, familial scaphocephaly syndrome, McGillivray type, Apert syndrome, LADD syndrome.
• PP3: No computational evidence supports a deleterious effect, but strongly conserved according to phyloP

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
FGFR2	NM_000141.5	c.1012_1013delinsAA	p.Gly338Lys	missense_variant	8/18	ENST00000358487.10	NP_000132.3
FGFR2	NM_022970.4	c.1087+1291_1087+1292delinsAA		intron_variant		ENST00000457416.7	NP_075259.4

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
FGFR2	ENST00000358487.10	c.1012_1013delinsAA	p.Gly338Lys	missense_variant	8/18	1	NM_000141.5	ENSP00000351276	A2
FGFR2	ENST00000457416.7	c.1087+1291_1087+1292delinsAA		intron_variant		1	NM_022970.4	ENSP00000410294	P4

Frequencies

GnomAD3 genomes Cov.: 32

We have no GnomAD4 exomes data on this position. Probably position not covered by the project.

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

FGFR2-related craniosynostosis Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Jul 31, 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. A different missense substitution at this codon (p.Gly338Glu) has been determined to be pathogenic (PMID: 8946174, 12575301, 24127277). This suggests that the glycine residue is critical for FGFR2 protein function and that other missense substitutions at this position may also be pathogenic. 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 disruptive, 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 FGFR2-related disease. This variant is not present in population databases (ExAC no frequency). This sequence change replaces glycine with lysine at codon 338 of the FGFR2 protein (p.Gly338Lys). The glycine residue is highly conserved and there is a moderate physicochemical difference between glycine and lysine. -

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: rs1554928905; hg19: chr10-123276904;