4-54267304-A-G

Position:

• chr4-54267304-A-G

Variant summary

Our verdict is Likely benign. Variant got -1 ACMG points: 3P and 4B. PM2 PP2 BP4_Strong

The NM_006206.6(PDGFRA):​c.775A>G​(p.Thr259Ala) variant causes a missense change. The variant allele was found at a frequency of 0.00000274 in 1,461,864 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 15/21 in silico tools predict a benign 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. T259I) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000027 (0 hom.)
• Consequence: PDGFRA NM_006206.6 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 3.84

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 Likely_benign. Variant got -1 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.
• BP4: Computational evidence support a benign effect (MetaRNN=0.06533831).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
PDGFRA	NM_006206.6	c.775A>G	p.Thr259Ala	missense_variant	6/23	ENST00000257290.10

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
PDGFRA	ENST00000257290.10	c.775A>G	p.Thr259Ala	missense_variant	6/23	1	NM_006206.6	P1
PDGFRA	ENST00000509092.5	n.593A>G		non_coding_transcript_exon_variant	5/15	1
PDGFRA	ENST00000509490.5	c.775A>G	p.Thr259Ala	missense_variant, NMD_transcript_variant	6/18	1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000274 AC: 4 AN: 1461864 Hom.: 0 Cov.: 33 AF XY: 0.00000275 AC XY: 2 AN XY: 727234

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: 0.00000360

Gnomad4 OTH exome AF: 0.00

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

Labcorp Genetics (formerly Invitae), Labcorp

Jan 04, 2024

This sequence change replaces threonine, which is neutral and polar, with alanine, which is neutral and non-polar, at codon 259 of the PDGFRA protein (p.Thr259Ala). This variant is not present in population databases (gnomAD no frequency). This variant has not been reported in the literature in individuals affected with PDGFRA-related conditions. ClinVar contains an entry for this variant (Variation ID: 407383). An algorithm developed to predict the effect of missense changes on protein structure and function (PolyPhen-2) suggests that this variant is likely to be tolerated. 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. -

Hereditary cancer-predisposing syndrome Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Feb 12, 2022

The p.T259A variant (also known as c.775A>G), located in coding exon 5 of the PDGFRA gene, results from an A to G substitution at nucleotide position 775. The threonine at codon 259 is replaced by alanine, an amino acid with similar properties. This amino acid position is conserved. In addition, this alteration is predicted to be tolerated 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	Benign	0.091
BayesDel_addAF	Benign	-0.19	T
BayesDel_noAF	Benign	-0.51
CADD	Benign	16
DANN	Benign	0.74
DEOGEN2	Benign	0.095	T
Eigen	Benign	-0.79
Eigen_PC	Benign	-0.74
FATHMM_MKL	Benign	0.40	N
LIST_S2	Benign	0.59	T
M_CAP	Benign	0.016	T
MetaRNN	Benign	0.065	T
MetaSVM	Benign	-1.0	T
MutationAssessor	Benign	0.90	L
MutationTaster	Benign	1.0	N;N
PrimateAI	Benign	0.36	T
PROVEAN	Benign	-0.64	N
REVEL	Benign	0.078
Sift	Benign	0.67	T
Sift4G	Benign	0.74	T
Polyphen		0.051	B
Vest4		0.24
MutPred		0.32		Gain of ubiquitination at K256 (P = 0.0798);
MVP		0.60
MPC		0.32
ClinPred		0.093	T
GERP RS		1.2
Varity_R		0.054
gMVP		0.55

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.040		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: rs1060501503; hg19: chr4-55133471;