Higher rates of autism in children with various congenital disorders

Children with Congenital Heart Disease, Tuberous Sclerosis Complex, Duchenne Muscular Dystrophy, Ehlers-Danlos Syndrome suffer high rates of autism.

Congenital heart defects (CHD) and autism

In the first two studies of their kind a positive association was found between congenital heart defects in infants and risk of developing autism symptoms later in life. In the first case, a team of clinicians and researchers from The Children’s Hospital of Philadelphia screened 195 children with a history of congenital heart defects. Measures included behavioural data from neurodevelopmental evaluations from four years previously, and parent-report data from a later annual follow-up.

These findings showed much higher risk of autism in this group compared to the rates of autism in the general population. The study also found that children with a history of severe CHD requiring infant surgery were at the highest risk for screening positive for autism symptoms.

In the second paper, which was based on a nationwide population-based case-control study of a Taiwanese cohort of 3552 children, CHD was once again identified as an independent risk factor for both ADHD and autism. The authors highlight the need for a careful screening and specialist referral to assess the presence of social-communication problems, with the view of offering early intervention in order to achieve best possible outcomes in children with CHD.

Muscular dystrophy and autism

A recent investigation on a cohort of boys with Duchene Muscular Dystrophy has observed significantly higher rate of autism compared to general population, thus confirming earlier findings of increased prevalence of cognitive and neurodevelopmental disorders in patients with muscular dystrophies.

Tuberous sclerosis complex (TSC) and autism

TSC is associated with a high neurological and neuropsychiatric morbidity, including seizures, aggressive behaviours and autism. The mammalian/ mechanistic target of rapamycin (mTOR) pathway is a key signalling pathway that has been implicated in TSC as well as cognitive impairments, neurodegenerative diseases and genetic epilepsy syndromes. Although the precise pathological mechanisms behind the emergence of autism and other neurophsychiatric manifestations in TSC are still unknown, microglial activation as a downstream consequences of the lack of inhibition of the mTOR pathway is suspected to play a major role.

Everolimus, a potent mTOR inhibitor with strong neuro-inflammation attenuating effects, has been observed to lead to a reduction in autism symptoms in some children who suffer concurrent TSC, epilepsy and autism. It is believed that TSC therefore offers a valuable model for understanding and treating the mechanisms that underlie idiopathic autism.

Neurofibromatosis Type 1 (NF1) and autism

NF1 is another monogenetic disorder with a very high incidence of neuropsychiatric disorders and cognitive impairments, with almost three quarters of affected children suffering speech and language delays, and an estimated quarter meeting full diagnostic criteria for autism.

Ehlers-Danlos Syndrome (EDS) and autism

A recent Swedish nationwide population-based matched cohort study found that individuals with EDS are at increased risks of many psychiatric disorders, including autism. These risk increases may have a genetic and/or early environmental background, as suggested by the evidence showing that siblings of EDS patients also have elevated risks of certain psychiatric disorders.

References:

Bean Jaworski J.L., Flynn T., Burnham N., et al. (2017) Rates of autism and potential risk factors in children with congenital heart defects. Congenit Heart Dis. Mar 16. doi: 10.1111/chd.12461.

Cederlöf M, Larsson H, Lichtenstein P, et al. (2016) Nationwide population-based cohort study of psychiatric disorders in individuals with Ehlers-Danlos syndrome or hypermobility syndrome and their siblings. BMC Psychiatry. Jul 4;16:207. doi: 10.1186/s12888-016-0922-6.

Colombo P., Nobile M., Tesei A., et al. (2017) Assessing mental health in boys with Duchenne muscular dystrophy: Emotional, behavioural and neurodevelopmental profile in an Italian clinical sample. Eur J Paediatr Neurol. Mar 24. pii: S1090-3798(17)30183-6. doi: 10.1016/j.ejpn.2017.02.007.

Kilincaslan, A., Kok, B., Tekturk, P., Yalcinkaya, C., Ozkara, C. and Yapici, Z. (2017). Beneficial Effects of Everolimus on Autism and Attention-Deficit/Hyperactivity Disorder Symptoms in a Group of Patients with Tuberous Sclerosis Complex. Journal of Child and Adolescent Psychopharmacology, 27(4), pp.383-388. doi: 10.1089/cap.2016.0100.

Mitchell R., Barton S., Harvey A.S., et al. (2017) Risk factors for the development of autism spectrum disorder in children with tuberous sclerosis complex: protocol for a systematic review. Syst Rev. Mar 8;6(1):49. doi: 10.1186/s13643-017-0448-0.

Mizuguchi, M., Ikeda, H., Kagitani-Shimono, K., Yoshinaga, H., Suzuki, Y., Aoki, M., Endo, M., Yonemura, M. and Kubota, M. (2018). Everolimus for epilepsy and autism spectrum disorder in tuberous sclerosis complex: EXIST-3 substudy in Japan. Brain and Development. doi: 10.1016/j.braindev.2018.07.003.

Morris S.M., Acosta M.T., Garg S., et al. (2016) Disease Burden and Symptom Structure of Autism in Neurofibromatosis Type 1: A Study of the International NF1-ASD Consortium Team (INFACT). JAMA Psychiatry. Dec1;73(12):1276-1284. doi: 10.1001/jamapsychiatry.2016.2600.

Tsao P.C., Lee Y.S., Jeng M.J., et al. (2017) Additive effect of congenital heart disease and early developmental disorders on attention-deficit/hyperactivity disorder and autism spectrum disorder: a nationwide population-based longitudinal study. Eur Child Adolesc Psychiatry. Apr 17. doi: 10.1007/s00787-017-0989-8.

Wilbur C., Sanguansermsri C., Chable H., et al. (2107) Manifestations of Tuberous Sclerosis Complex: The Experience of a Provincial Clinic. Can J Neurol Sci. Jan;44(1):35-43. doi: 10.1017/cjn.2016.311.

Further reading:

Sato A. (2016) mTOR, a Potential Target to Treat Autism Spectrum Disorder. CNS Neurol Disord Drug Targets. 15(5):533-43. Doi: 10.2174/1871527315666160413120638.

Yang M.T., Lin Y.C., Ho W.H.,( 2017) Everolimus is better than rapamycin in attenuating neuroinflammation in kainic acid-induced seizures. J Neuroinflammation. Jan 21;14(1):15. doi: 10.1186/s12974-017-0797-6.

Young H.K., Barton B.A., Waisbren S., (2008) Cognitive and psychological profile of males with Becker muscular dystrophy. J Child Neurol. Feb;23(2):155-62. doi: 0.1177/0883073807307975.