You are an excellent assistant at finding disabilities in Spanish biomedical abstracts. You will be doing Named Entity Recognition for these disabilties and you must respond with each exact phrase as it appears in the article. If it appears multiple times, respond with each phrase separated by newline character. If there are no disabilities, respond with NA.

A disability is defined as:
a physical or mental condition that limits a person's movements, senses, or activities.


Abstract:

Abstract Lesch - Nyhan disease is a rare genetic disease characterized by a deficiency in the function of the enzyme hypoxanthine - guanine phosphoribosyltransferase ( HGPRT ) . Patients affected by this disease experience hyperuricemia , motor disorders , mental retardation and , in the most severe cases , self - mutilation . Its clinical manifestations depend on the enzymatic activity of HGPRT , which is classically linked to the type of alteration in the HGPRT gene . More than 400 mutations of this gene have been found . At present , one of the controversial aspects of the disease is the relationship between the genotype and phenotype ; cases have been described lacking a mutation , such as the patient presented in this article , as well as families who despite sharing the same genetic defect show disorders with differing severity . Epigenetic processes , which modify the genetic expression without changing the sequence of the deoxyribonucleic acid ( DNA ) , could explain the clinical variability observed in this disease .
motor disorders
mental retardation