DPPX (dipeptidyl-peptidase-like protein 6) is a type of autoimmune encephalitis.
Target: subunit of the Kv4.2 potassium channel (affects somatodendritic signal integration and attenuation of back-propagation of action potentials)
Clinical presentation:
(1) diarrhea
(2) other gastrointestinal symptoms
(3) unexplained weight loss
Neurologic features:
(1) cognitive and mental deficits
(2) CNS excitability (tremor, myoclonus, seizures, hyperekplexia)
(3) occasionally PERM (muscle rigidity, brainstem symptoms, myoclonus)
Laboratory findings:
(1) presence of IgG1 and IgG4 antibodies to DPPX
The syndrome is usually responsive to immunotherapy.
