An individual has a functional disability if the individual has a severe, chronic disability that: is attributable to a mental or physical impairment or a combination of mental and physical impairments, including a head injury; is likely to continue indefinitely; results in substantial functional limitations in at least three of the following areas of major life activity: self-care; receptive and expressive language; learning; mobility; self-direction; capacity for independent living; and economic self-sufficiency; and reflects the individual’s need for a combination and sequence of special interdisciplinary or generic care, treatment, or other services that are: lifelong or of extended duration; and individually planned and coordinated. An individual has a developmental disability if the individual has a functional disability that is manifested before the individual attains the age of 22 years.