Draft:Houge-Janssens Syndrome

Houge-Janssens Syndrome is a rare neurodevelopmental disorder in people. It is characterized by a combination of symptoms including intellectual delay, epilepsy, hypotonia, brain abnormality, behavioral problems, and digestive dysfunction. Many of those diagnosed also qualify for diagnosis with autism spectrum disorder.

Genetics
There are three recognized subtypes of Houge-Janssens Syndrome. Houge-Janssens Syndrome Type 1, a.k.a. Jordan's Syndrome, is caused by a pathogenic variant of the gene PPP2R5D. Types 2 and 3 are caused by pathogenic variants of the genes PPP2R1A and PPP2CA respectively. Each of those genes encodes a subunit of the PP2A holoenzyme. A number of pathogenic variants have been identified for each gene leading to the presentation of the disease occurring on a spectrum.

Signs and symptoms
Neurological symptoms include intellectual and developmental delay ranging from mild to profound in degree.