A multimodal MRI, MRS and MEG magnetoencephalography design is employed in cohorts of boys with XYY, who are symptomatic for ASD and control cohorts of idiopathic ASD ASD-I and typical development TD. Targeted recruitment for year 1 totaled 30 enrolled. At the point of this report, 25 subjects have been enrolled, 5 were eliminated for not meeting inclusion criteria upon clinical assessment, 19 have completed data acquisition, and 1 is pending imaging completion. Three of the 19 are pending confirmation of ASD diagnosis. Several more are in various stages of recruitment, scheduling,neuropsychological evaluation or imaging. MRI, MRS and MEG examinations have been conducted in the 17 subjects above with confirmed diagnoses 8TD,8XYY ASD, 1 ASD-I. QA suggests in general that complete studies have been tolerated and that data quality is good in the majority of cases. Additional steps to remove MEG trials corrupted by excessive head motion are underway to improve further the evaluable data yield. Data analysis is ongoing, priority having been given to standard approaches for MEG source localization in BESA followed by consensus peak picking, MRS alignment of on and off spectra, then subtraction and Gaussian modeling of the GABA and Cr resonances in GANNET and DTIHARDI. As mentioned above, about 50 of the data tolerated this strategy robustly. The remaining data are undergoing scrubbing to eliminate motion-related artifacts and reduce noise, to accommodate comparable analysis these data are likely evaluable, but are not reported herein. Dependent variable extraction is underway and preliminary data are shown for illustration of feasibility. It is premature to conduct formal statistical analyses. Recruitment, acquisition and analysis is on track and completion is anticipated in the remaining 12 months of this award.