2-5 years with ASD, other developmental disabilities (DD), and from the general population (POP); and 2) longitudinal follow-up of and research on previous SEED participants to obtain information through early adulthood on their health and functioning, service use and needs, and the impact of ASD on their families.These activities will be accomplished through five components (A-E):Component A: Enhanced Epidemiologic Research Using Existing SEED Data Follow-up Surveys of Existing SEED ParticipantsTo conduct analyses of existing SEED data and follow-up surveys of participants from SEED Phases 1, 2, and 3 (referred to as SEED 1-3) to:Address current research gaps, and publish findings related to risk factors for ASD and the characteristics and needs of children with ASD; andSupport the implementation of follow-up surveys in collaboration with CDC from an existing list of SEED participants in SEED 1-3.Component B: In-Person Assessment of Intellectual Abilities of SEED Participants To conduct follow-up assessments of intellectual abilities on a subset of children and adolescents (aged ≥ 8 years), who were initially identified as having ASD or another DD in SEED 1-3 and who completed the follow-up surveys implemented through Component A of this NOFO. To be funded for Component B, applicants must apply and be funded for Component A.Component C: Maternal Auto-Antibody Testing To conduct assays of maternal autoantibodies reactive to proteins in the fetal brain using stored SEED 1 and 2 samples and to conduct analyses of the association between these maternal autoantibodies and ASD. To be funded for Component C, applicants must apply and be funded for Component A.Component D: Genetic Analyses To identify analytic priorities for generating and analyzing SEED genetic data; to develop and implement methods for combining existing SEED 1 genetic data and newly generated SEED 2 and 3 genetic data for use by SEED investigators and contribution to data repositories; and to support SEED investigators conducting analyses to increase understanding of the genetic risk factors for ASD and their interaction with environmental risk factors. To be funded for Component D, applicants must apply and be funded for Component A.Component E: Biorepository To maintain a repository of biospecimens previously collected from SEED 1-3 participants. To be funded for Component E, applicants must apply and be funded for Component A.Applicants should clearly indicate the components for which they are applying and should include, at the beginning of the title, the respective component under which the application should be considered (i.e., Component A, B, C, D, and/or E). A separate application is required for each component.