Objectives: As in introduction to the study, we will present NJLAGS in terms of its criteria for eligibility, the behavioral testing battery administered to subjects, the language phenotypes already developed, and preliminary language profiles of our ASD and SLI subjects to date.
Methods: Potential ASD probands are diagnosed using the ADI-R, the ADOS, and a comprehensive physician’s examination including the DSM-IV. SLI probands are diagnosed by a licensed Speech/Language Pathologist. Once it is determined that there are two probands, the rest of the nuclear family complete a comprehensive neuropsychological battery and donate a blood sample for DNA analysis.
Results: Thus far, 381 family members have given DNA samples and have completed the entire comprehensive behavioral battery. We have identified 80 subjects who meet criteria for Autism and 16 subjects who meet criteria for ASD. Included here is a preliminary profile of their language. Based on the ADI-R, 38% produced single word utterances by 24 months while 62% either produced them later than 24 months or are still non-verbal. Twenty eight percent of our sample has achieved phrase speech by 36 months while 72% achieved this later or still have not achieved this milestone. We examined the group of higher functioning ASD probands who were able to participate in the standardized language testing that was administered to other family members. As a group, the ASD probands scored between one and two standard deviations below matched peers on all language measures with relative strengths in various forms of vocabulary knowledge and relative weaknesses in grammar, inferential language, and the pragmatic use of language. Approximately 29% of family members met criteria for SLI based on at least four different phenotypes.
Conclusions: This research is the first large genetics study to look at the connection between language-based learning problems and autism in New Jersey. Detailed descriptions of the phenotypes and affectation rates of family members will be included as well as how these phenotypes might be applied to linkage analysis and already identified candidate genes.