For the purposes of this subchapter, the term “elderly or handicapped persons or families” means families which consist of two or more persons, the head of which (or his or her spouse) is at least sixty-two years of age or is handicapped. Such term also means a single person who is at least sixty-two years of age or is handicapped. A person shall be considered handicapped if such person is determined, pursuant to regulations issued by the Secretary, to have an impairment which (A) is expected to be of long-continued and indefinite duration, (B) substantially impedes his ability to live independently, and (C) is of such a nature that such ability could be improved by more suitable housing conditions, or if such person has a developmental disability as defined in section 15002 of this title . The Secretary shall prescribe such regulations as may be necessary to prevent abuses in determining, under the definitions contained in this paragraph, eligibility of families and persons for admission to and occupancy of housing constructed with assistance under this subchapter. Notwithstanding the preceding provisions of this paragraph, such term also includes two or more elderly (sixty-two years of age or over) or handicapped persons living together, one or more such persons living with another person who is determined (under regulations prescribed by the Secretary) to be essential to the care or well-being of such persons, and the surviving member or members of any family described in the first sentence of this paragraph who were living, in a unit assisted under this subchapter, with the deceased member of the family at the time of his or her death.