WHAT IS SPG50?

SPG50 is an autosomal recessive inherited disorder. Both parents must have a pathogenic (disease causing) genetic mutation in the gene AP4M1. There is a 25% chance that a child will inherit both parent’s pathogenic variants and will have spg50. AP4M1 is one of four genes that helps to carry out the proper function of the adaptor protein complex. This protein is essential to neuronal growth.

SPG50 is neurodegenerative. It is initially characterized by ventriculomegaly, microcephaly, global developmental delay (in particular speech impairment), low muscle tone in infancy, and febrile seizures. Low muscle tone eventually progresses to spasticity in the lower extremities, leading to severely impaired mobility and paraplegia by the age of 10 - and by the age of 20, quadriplegia.

Few individuals have survived into their 30’s.