13-28311732-C-T

Variant names:

• chr13-28311732-C-T
• NM_002019.4:c.3493G>A

Variant summary

Our verdict is Uncertain significance. The variant received 3 ACMG points: 3P and 0B. PM2 PP3

The NM_002019.4(FLT1):​c.3493G>A​(p.Asp1165Asn) variant causes a missense, splice region change. The variant allele was found at a frequency of 0.000000684 in 1,461,736 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 2/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: FLT1 NM_002019.4 missense, splice_region
• Scores: Splicing: ADA: 0.9988
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 5.08
• Publications: 0 publications found

Genes affected

FLT1 (HGNC:3763): (fms related receptor tyrosine kinase 1) This gene encodes a member of the vascular endothelial growth factor receptor (VEGFR) family. VEGFR family members are receptor tyrosine kinases (RTKs) which contain an extracellular ligand-binding region with seven immunoglobulin (Ig)-like domains, a transmembrane segment, and a tyrosine kinase (TK) domain within the cytoplasmic domain. This protein binds to VEGFR-A, VEGFR-B and placental growth factor and plays an important role in angiogenesis and vasculogenesis. Expression of this receptor is found in vascular endothelial cells, placental trophoblast cells and peripheral blood monocytes. Multiple transcript variants encoding different isoforms have been found for this gene. Isoforms include a full-length transmembrane receptor isoform and shortened, soluble isoforms. The soluble isoforms are associated with the onset of pre-eclampsia.[provided by RefSeq, May 2009]

ACMG classification

Our verdict: Uncertain_significance. The variant received 3 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: Splicing predictors support a deleterious effect. Scorers claiming Pathogenic: dbscSNV1_ADA, dbscSNV1_RF. Scorers claiming Uncertain: max_spliceai. No scorers claiming Benign.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
FLT1	NM_002019.4	c.3493G>A	p.Asp1165Asn	missense_variant, splice_region_variant	Exon 27 of 30	ENST00000282397.9	NP_002010.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
FLT1	ENST00000282397.9	c.3493G>A	p.Asp1165Asn	missense_variant, splice_region_variant	Exon 27 of 30	1	NM_002019.4	ENSP00000282397.4

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461736 Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0 AN XY: 727188

⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.

African (AFR) AF: 0.00 AC: 0 AN: 33478

American (AMR) AF: 0.00 AC: 0 AN: 44724

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26130

East Asian (EAS) AF: 0.00 AC: 0 AN: 39670

South Asian (SAS) AF: 0.00 AC: 0 AN: 86254

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53420

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5760

European-Non Finnish (NFE) AF: 8.99e-7 AC: 1 AN: 1111912

Other (OTH) AF: 0.00 AC: 0 AN: 60388

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0.000000), which strongly suggests a high chance of mosaicism in these individuals.

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

not specified Uncertain:1

Mar 07, 2024

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The c.3493G>A (p.D1165N) alteration is located in exon 27 (coding exon 27) of the FLT1 gene. This alteration results from a G to A substitution at nucleotide position 3493, causing the aspartic acid (D) at amino acid position 1165 to be replaced by an asparagine (N). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.10
BayesDel_addAF	Benign	0.0046	T
BayesDel_noAF	Benign	-0.23
CADD	Pathogenic	31
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.67	D;.;.
Eigen	Uncertain	0.57
Eigen_PC	Uncertain	0.59
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.95	D;D;D
M_CAP	Uncertain	0.10	D
MetaRNN	Benign	0.34	T;T;T
MetaSVM	Uncertain	-0.11	T
MutationAssessor	Uncertain	2.7	M;.;.
PhyloP100		5.1
PrimateAI	Uncertain	0.59	T
PROVEAN	Uncertain	-3.2	D;.;D
REVEL	Uncertain	0.40
Sift	Uncertain	0.0040	D;.;D
Sift4G	Uncertain	0.012	D;D;D
Polyphen		0.98	D;.;.
Vest4		0.32
MutPred		0.51		Loss of helix (P = 0.0558);.;.;
MVP		0.81
MPC		0.71
ClinPred		0.98	D
GERP RS		6.2
Varity_R		0.26
gMVP		0.40
Mutation Taster		=58/42	polymorphism

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.95
SpliceAI score (max)		0.25		Details are displayed if max score is > 0.2
DS_AL_spliceai		0.25		Position offset: 0

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

Other links and lift over

hg19: chr13-28885869;