Any disability attributable to mental retardation, autism, cerebral palsy, epilepsy or other disabling neurological condition that requires training or support similar to that required by persons with mental retardation, if either of the following apply:
(A) The disability originates before the person attains 22 years of age, or if the disability is attributable to mental retardation the condition is manifested before the person attains 18 years of age, the disability can be expected to continue indefinitely, and the disability constitutes a substantial handicap to the ability of the person to function in society.
(B) The disability results in a significant subaverage general intellectual functioning with concurrent deficits in adaptive behavior that are manifested during the developmental period.