Mice with TSC1 mutations have unusually short day-night cycles, and their body temperature does not fluctuate throughout the day as it should. People with tuberous sclerosis have mutations in the genes TSC1 or TSC2, as well as difficulty falling and staying asleep. Tuberous sclerosis is a condition associated with autism and is characterized by benign tumors throughout the brain and body. “We’re starting to understand the clock as a really important focal point,” he says. And mice with disrupted clocks have problems with memory, metabolism, body temperature regulation and other key processes 2, 3, 4.ĭisrupting the clock may have profound effects on the brain and behavior, says Lipton. For instance, the suppression of clock genes in cancer cells has been linked to tumor growth 1. Mutations or other disruptions that affect the clock can have serious consequences. The clock controls slumber, cell division and a host of other crucial processes that happen at specific times of day. It helps regulate the expression of genes, turning up to 40 percent of the genome on or off.
The circadian clock is a complex of proteins that forms every 24 hours in almost every cell in the body. “This is a very active and needed area of investigation,” says Jonathan Lipton, a pediatric neurologist at the Boston Children’s Hospital Sleep Center. But several genetic conditions associated with autism, including tuberous sclerosis, fragile X syndrome and Prader-Willi syndrome, may involve mutations that interfere with the clock. So far, no evidence ties any of the top autism genes to the circadian clock. These changes may disrupt the circadian clock, a molecular timer that keeps cells in sync with the night-day cycle. Studies over the past few years suggest that sleep problems may stem from the same mutations that underlie other, more characteristic features of autism. There is, however, mounting evidence that poor sleep may not be just a side effect of autism or its treatments, but rather a central feature of it.
Some have anxiety or behavioral difficulties that make it hard to wind down others take medications that disrupt sleep. For many people with autism, sleep doesn’t come naturally.