PDGFRA (platelet-derived growth factor receptor, alpha polypeptide)

4q12

Composed of an extracellular domain (the immunoglobulin-like motifs), a transmembrane domain, with an inhibitory juxtamembrane WW-like domain (Irusta et al., 2002), and an intracellular domain (kinase domain); receptor tyrosine kinase; forms homodimer, and heterodimer with PDGFRB; dimerization induces kinase domain activation, leading to the activation of intracellular signalling pathways (Kawagishi et al., 1995).

Hybrid genes between various partners and PDFRGA occur in chronic myeloid leukaemia-like diseases with eosinophilia, mostly chronic eosinophilic leukemia (CEL), a clonal hypereosinophilic syndrome. PDGFRA partners known so far are: STRN (2p24) (Curtis et al., 2007), FIP1L1 (4q12) (Cools et al., 2003, Pardanani et al., 2004), CDK5RAP2 (9q33) (Walz et al., 2006), KIF5B (10p11) (Score et al., 2006), ETV6 (12p13), herein described (Curtis et al., 2007), and BCR (22q11) (Baxter et al., 2002).
Mutations of platelet-derived growth factor receptor-alpha (PDGFRA) are observed in a subset of gastrointestinal stromal tumors (GISTs) (Heinrich et al., 2003).
Tumours with PDGFRA involvement are responsive to imatinib therapy (Cools et al., 2003; Debiec-Rychter et al., 2004).

ETV6 (ets variant 6)

12p13.2

Contains a HLH domain and a ETS-DNA binding domain; ETS-related transcription regulator.