Autism spectrum disorders (ASDs) are common and have a strong genetic basis, yet the cause of ∼70-80% ASDs remains unknown. By clinical cytogenetic testing, we identified a family in which two brothers were diagnosed with ASDs. The family's genetic history revealed a rare inherited mutation that was not previously associated with ASDs. This study aims to investigate the role of this mutation in the development of ASDs and to identify potential therapeutic targets. The findings of this study have significant implications for the diagnosis and treatment of ASDs, and highlight the importance of genetic testing in understanding the causes of this complex disorder.