(b)"medical authority" means the medical authority as referred to in clause (p) of section 2 of the Persons with Disabilities (Equal Opportunities, Protection of Rights and Full Participation) Act, 1995 (1 of 1996), or such other medical authority as may, by notification, be specified by the Central Government for certifying "autism", "cerebral palsy", "multiple disabilities", "person with disability" and "severe disability" referred to in clauses (a), (c), (h), (j) and (o) of section 2 of the National Trust for Welfare of Persons with Autism, Cerebral Palsy, Mental Retardation and Multiple Disabilities Act, 1999 (44 of 1999);