4-54274588-T-C

Position:

• chr4-54274588-T-C

Variant summary

Our verdict is Uncertain significance. Variant got 5 ACMG points: 5P and 0B. PM2 PP2 PP3_Moderate

The NM_006206.6(PDGFRA):​c.1616T>C​(p.Ile539Thr) variant causes a missense change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. 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. I539V) has been classified as Uncertain significance.

• Frequency: Genomes: not found (cov: 32)
• Consequence: PDGFRA NM_006206.6 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 7.28

Genes affected

PDGFRA (HGNC:8803): (platelet derived growth factor receptor alpha) This gene encodes a cell surface tyrosine kinase receptor for members of the platelet-derived growth factor family. These growth factors are mitogens for cells of mesenchymal origin. The identity of the growth factor bound to a receptor monomer determines whether the functional receptor is a homodimer or a heterodimer, composed of both platelet-derived growth factor receptor alpha and beta polypeptides. Studies suggest that this gene plays a role in organ development, wound healing, and tumor progression. Mutations in this gene have been associated with idiopathic hypereosinophilic syndrome, somatic and familial gastrointestinal stromal tumors, and a variety of other cancers. [provided by RefSeq, Mar 2012]

ACMG classification

Verdict is Uncertain_significance. Variant got 5 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP2: Missense variant in gene, where missense usually causes diseases (based on misZ statistic), PDGFRA. . Gene score misZ 1.9401 (greater than the threshold 3.09). Trascript score misZ 3.4078 (greater than threshold 3.09). GenCC has associacion of gene with congenital heart disease, polyps, multiple and recurrent inflammatory fibroid, gastrointestinal, gastrointestinal stromal tumor, isolated cleft palate.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.867

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
PDGFRA	NM_006206.6	c.1616T>C	p.Ile539Thr	missense_variant	11/23	ENST00000257290.10

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
PDGFRA	ENST00000257290.10	c.1616T>C	p.Ile539Thr	missense_variant	11/23	1	NM_006206.6	P1
PDGFRA	ENST00000509092.5	n.1434T>C		non_coding_transcript_exon_variant	10/15	1
PDGFRA	ENST00000509490.5	c.1616T>C	p.Ile539Thr	missense_variant, NMD_transcript_variant	11/18	1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Gastrointestinal stromal tumor Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Feb 15, 2017

This variant is not present in population databases (ExAC no frequency) and has not been reported in the literature in individuals with a PDGFRA-related disease. 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. In summary, this variant is a novel missense change with uncertain impact on protein function. It has been classified as a Variant of Uncertain Significance. This sequence change replaces isoleucine with threonine at codon 539 of the PDGFRA protein (p.Ile539Thr). The isoleucine residue is highly conserved and there is a moderate physicochemical difference between isoleucine and threonine. -

Hereditary cancer-predisposing syndrome Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Apr 28, 2023

The p.I539T variant (also known as c.1616T>C), located in coding exon 10 of the PDGFRA gene, results from a T to C substitution at nucleotide position 1616. The isoleucine at codon 539 is replaced by threonine, an amino acid with similar properties. This amino acid position is conserved. In addition, this alteration is predicted to be deleterious by in silico analysis. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Uncertain	0.52
BayesDel_addAF	Pathogenic	0.38	D
BayesDel_noAF	Pathogenic	0.30
CADD	Pathogenic	26
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.51	D
Eigen	Pathogenic	0.81
Eigen_PC	Pathogenic	0.78
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.94	D
M_CAP	Uncertain	0.090	D
MetaRNN	Pathogenic	0.87	D
MetaSVM	Uncertain	0.34	D
MutationAssessor	Pathogenic	3.0	M
MutationTaster	Benign	1.0	D;D
PrimateAI	Pathogenic	0.90	D
PROVEAN	Benign	-2.3	N
REVEL	Uncertain	0.64
Sift	Uncertain	0.0010	D
Sift4G	Uncertain	0.0030	D
Polyphen		1.0	D
Vest4		0.85
MutPred		0.50		Gain of sheet (P = 0.0477);
MVP		0.89
MPC		1.2
ClinPred		0.98	D
GERP RS		5.9
Varity_R		0.23
gMVP		0.87

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.020		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: rs1553904366; hg19: chr4-55140755;