According to a new study of autistic people and their relatives, the genetic factors that have a role in autism may be entwined with those that underlie insomnia. This discovery may be able to help explain the common co-occurrence of autism and sleep issues. According to previous research, up to 90 percent of people with autism encounter disrupted sleep, and approximately 30 percent have a clinical diagnosis of a certain sleep disorder. The study reveals that close relatives of those with autism are also at a high risk to develop insomnia.
50,097 autistic people, along with nearly 56,000 of their full siblings, 31,669 half-siblings and 214,665 cousins were identified by using the Swedish national health registries. Approximately 23 percent of the autistic participants suffered from insomnia or took melatonin, in comparison with 1.1 percent of the control group participants. The study showed that the more closely related the relatives are to the austistic individual, the higher the chances that they will suffer from sleeping issues. For example, identical twins had about 6.6 times the typical odds of suffering from insomnia, while cousins had approximately 1.3 times the usual odds. Out of this study, shared genetic factors explained 94 percent of the correlation, whilst nonshared environmental influences accounted for only 6 percent.
Study: Etiological links between autism and difficulties in initiating and maintaining sleep: a familial co-aggregation and twin study