The Safety and Tolerability of Kinetin, in Patients With Familial Dysautonomia

This is a study of kinetin, a nutritional supplement that corrects the mRNA splicing defect in patients with familial dysautonomia (FD, also known as Riley Day syndrome or hereditary sensory and autonomic neuropathy type III). FD is a rare fatal autosomal recessive disease in which the growth and development of selective neuronal populations is impaired. The disease is the result of a point mutation in the gene sequence that encodes for kinase complex associated protein (IKAP) in chromosome 9q31. The mutation, at the start of the non-encoding intron 20, weakens the splice site, causing the spliceosome to wrongly join together exons 19 and 21 when transcribing the mRNA strand and miss out exon 20. The mutated mRNA produces a short unstable IKAP protein that is quickly degraded. Interestingly, the mutation does not lead to a complete loss of function. Instead, it results in a tissue specific deficiency in splicing efficiency with both normal (wild type) and mutant IKAP mRNA being expressed in different ratios in different tissues. Some cells, like fibroblasts, produce mostly normal mRNA and protein, where as others, like neurons, produce mostly mutant mRNA and almost no functional protein product.