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:

Different studies show that mental retardation affects 1 - 3 % of the population , and in about 50 % of the cases the aetiology is unknown . The uncertainty on the aetiology , and recurrence , means that prevention of mental retardation can have serious , therapeutic , social , and even economic repercussions . The key is to obtain an accurate diagnosis , proving a clinical hypothesis by the accomplishment of the most suitable genetic tests . Due to the increasing development of the technology in the field of the genetics , and the availability of new tests , this article reviews the criteria established in the practice guidelines from different scientific societies ( paediatric , neurological and genetic ) with respect to their use in diagnosis and integrates them from the point of view of their use in mental retardation and developmental delay .
mental retardation
mental retardation
mental retardation
developmental delay