[5] Other genetic abnormalities in PDGFRB lead to various forms of potentially malignant bone marrow disorders: small deletions in and chromosome translocations causing fusions between PDGFRB and any one of at least 30 genes can cause Myeloproliferative neoplasms that commonly involve eosinophilia, eosinophil-induced organ injury, and possible progression to aggressive leukemia (see blow).

Upon PDGF binding the dimerization of receptor releases the inhibitory conformations due to auto-phosphorylation of regulatory tyrosine residues in trans fashion.

The activated receptor phosphorylates itself and other proteins, and thereby engages intracellular signaling pathways that trigger cellular responses such as migration and proliferation.

Eliminating either PDGFRB, or PDGF-B reduces the number of pericytes and vascular smooth muscle cells, and thereby compromises the integrity and/or functionality of the vasculature in multiple organs, including the brain, heart, kidney, skin and eye.

[15] Mice harboring a single activated allele of PDGFRB show a number of postnatal phenotypes including reduced differentiation of aortic vascular smooth muscle cells and brain pericytes.

The ETV6 gene codes for a transcription factor protein that in mice appears to be required for hematopoiesis and maintenance of the developing vascular network.

The drug often causes long-term complete hematological and cytogenic remissions as doses well below those used to treat chronic myelogenous leukemia.

In all instances, these gene fusion diseases are considered types of clonal eosinophilia with recommended treatment regimens very different than those of similar hematological malignancies.

Diagnosis relies on cytogenetic analyses to detect breakpoints in the long arm of chromosome 5 by Fluorescence in situ hybridization.

[6][22][33] Primary familial brain calcification (see Fahr's syndrome) is a rare disease involving bilateral calcifications in the brain, predominantly in basal ganglia but also cerebellum, thalamus, and brainstem in patients presenting with diverse neurologic (e.g. movement disorders, parkinsonism, seizures, headache) features and psychiatric (e.g. cognitive impairment, mood disorders, psychotic symptoms, and obsessive-compulsive) disturbances.

PDGFRB is extensively expressed in the neurons, chorioid plexus, vascular smooth muscle cells, and pericytes of the human brain, particularly the basal ganglia and the dentate nucleus.