Epigenetic modulation of human neurobiological disorders: Lesch-Nyhan disease as a model disorder.

Epigenetics is the study of how cells control gene activity without changing the DNA sequence. Epigenetic changes affect how genes are turned on and off or expressed, and thus help regulate how cells in different parts of the body use the same genetic code. Errors in the epigenetic process can not only lead to abnormal gene activity or inactivity, but can also influence alternative splicing (AS) and could cause human diseases. Understanding of how epigenetic defects can affect human health, especially for neurological disorders, could suggest targets for therapeutic interventions. For such a purpose, the Lesch-Nyhan disease (LND) has been selected as a valuable model to study the genetic-epigenetic interplay, especially to explore the epistasis between the housekeeping hypoxanthine phosphoribosyltransferase 1 (HPRT1) and β-amyloid precursor protein (APP) genes. This review is structured as follows: we begin with an overview about the monogenetic neurological disorders associated with epigenetic changes; next, the current knowledge on HPRT1 and APP genes is provided; then, the epistasis between HPRT1 and APP genes related to the neurobehavioral syndrome in LND is described; and finally, we present the construction of expression vectors to study intermolecular interactions between the hypoxanthine-guanine phosphoribosyltransferase (HGprt) enzyme and APP in LND. Information obtained from such expression vectors would be useful for future directions to design therapies through epigenetic interventions.