Proband and Familial Autoimmune Diseases Are Associated With Proband Diagnosis of Autism Spectrum Disorders.

OBJECTIVE: There is evidence that parental autoimmune diseases (ADs) are associated with autism spectrum disorders (ASD) in offspring. The association between offspring ASD and ADs diagnosed in siblings and probands remains less clear. We examined whether proband and familial diagnoses of ADs were associated with increased odds of ASD in probands. METHOD: The study is based on a nested case-control design that used data from a large national birth cohort (N = 1.2 million) in Finland. There were 4,600 cases of ASD and controls matched 1:4 on date of birth, sex, and residence. Data were accessed from national medical, birth, and central registries. RESULTS: Probands had a statistically significant increase in odds of ASD when they (adjusted odds ratio [OR] = 1.2), their mother (adjusted OR = 1.1), or their sibling (adjusted OR = 1.2) were diagnosed with an AD. With regard to specific ADs, we found a statistically significant increase in odds of ASD in probands diagnosed with autoimmune thyroiditis (adjusted OR = 2.7). Further analyses considering ADs by body system yielded a statistically significant increase in odds of ASD in probands with ADs associated with the central/peripheral nervous (adjusted OR = 4.8) and skin/mucous membrane (adjusted OR = 1.3) systems. Probands of mothers diagnosed with ear/eye (adjusted OR = 1.6) or respiratory (adjusted OR = 1.4) ADs, or siblings diagnosed with skin/mucous membrane ADs (adjusted OR = 1.3) also had increased odds of ASD. CONCLUSION: The findings suggest that there may be common pathogenic, developmental mechanisms related to autoimmunity that are associated with the etiology of ASD.

Brief Report: Syndromes in Autistic Children in a Finnish Birth Cohort.

We studied the association between specific congenital syndromes and autism spectrum disorders (ASD) in the large Finnish Register material. Our data include all children diagnosed with ASD (n = 4441) according to Finnish Hospital Discharge Register in 1987-2000. Four controls per each case were matched to sex, birthplace, date of birth (±30 days) and residence in Finland (n = 17,695). The prevalence of specific congenital syndromes in the Finnish Register of Congenital Malformations was evaluated among the ASD group and the controls by sex. The results of this study suggest that there is an association between several etiologically different syndromes and ASD when compared to controls without ASD. Statistically significant associations were observed with 47,XYY, Sotos syndrome, neurofibromatosis I, and syndrome not otherwise specified. Syndromes were more common among males with ASD compared to controls. These results support the previous studies of etiological heterogeneity of ASD and have importance in clinical examination, management and rehabilitation.

The association between autism spectrum disorders and congenital anomalies by organ systems in a Finnish national birth cohort.

The aim of this study was to evaluate the association between autism spectrum disorders (ASD) with and without intellectual disability (ID) and congenital anomalies (CAs) by organ system. The sample included all children diagnosed with ASD (n = 4441) from the Finnish Hospital Discharge Register during 1987-2000 and a total of four controls per case (n = 17,695). CAs of the eye, central nervous system, and specific craniofacial anomalies were most strongly associated with ASD. Children with ASD and co-occurring ID were more likely to have CAs compared to ASD children without ID. The results suggest that some cases of ASD may originate during organogenesis, in the early first trimester of pregnancy. The results of this study may be useful for identifying prenatal etiological factors and elucidating the molecular pathogenesis of ASD.

The association between congenital anomalies and autism spectrum disorders in a Finnish national birth cohort.

AIM: The first aim of this study was to evaluate the association between different subgroups of autism spectrum disorders (ASDs) (childhood autism, Asperger syndrome, and pervasive developmental disorder/pervasive developmental disorder - not otherwise specified [PDD/PDD-NOS]) and congenital anomalies. Second, we assessed the association among intellectually disabled children with ASDs in the subgroups of childhood autism and PDD/PDD-NOS. METHOD: Nationwide population-based register data for children with a diagnosis of ASD (n=4449; 3548 males, 901 females) were collected during years 1987-2000 from the Finnish Hospital Discharge Register. Data on congenital anomalies were derived from the National Register of Congenital Malformations. Conditional logistic regression models were used as a statistical method. The association between ASD subgroups and congenital anomalies was stratified by the presence or absence of intellectual disability. RESULTS: Congenital anomalies occurred more frequently in all subgroups of ASD than in comparison participants (adjusted odds ratio [OR] for major congenital anomalies 1.8, 95% confidence interval [CI] 1.5-2.2, p<0.001). The association between congenital anomalies and childhood autism (OR 2.4, 95% CI 1.6-3.6, p<0.001) and between congenital anomalies and PDD/PDD-NOS (OR 3.7, 95% CI 2.4-5.7, p<0.001) among children with an intellectual disability was strong but remained significant also without intellectual disability (childhood autism: OR 1.7, 95% CI 1.3-2.3, p<0.001; PDD/PDD-NOS: OR 2.3, 95% CI 1.9-2.8, p<0.001). INTERPRETATION: The results suggest a significant association between ASDs and congenital anomalies regardless of the ASD subgroup. The association between childhood autism and PDD/PDD-NOS and congenital anomalies is stronger among children with intellectual disability is stronger than among those without intellectual disability. These results may have relevance in examining early risk factors in autism during fetal neurodevelopment.

A nationwide register study of the characteristics, incidence and validity of diagnosed Tourette syndrome and other tic disorders.

AIM: The aim of this study was to describe the characteristics and incidence rates of diagnosed tic disorders in the Finnish Hospital Discharge Register, including changing incidence rates between 1991 and 2010. We also aimed to validate the diagnoses of Tourette's syndrome recorded in the register. METHODS: Children born between January 1, 1991 and December 31, 2010, who were diagnosed with tic disorders, were identified from the Finnish Hospital Discharge Register (n = 3003). We studied the validity of the Tourette's syndrome diagnoses by reviewing the medical charts of 88 children born since 1997 and carrying out telephone interviews with 55 of their guardians. RESULTS: The incidence rates of all diagnosed tic disorders increased during the study period. A comorbid diagnosis of hyperkinetic disorder diagnosis was recorded in 28.2% of the children with Tourette's syndrome, and the validity of the register-based Tourette's syndrome diagnosis was approximately 95%. CONCLUSION: This is the first nationwide study to demonstrate the increasing incidence of all register-based tic disorder diagnoses. The validity of the Tourette's syndrome diagnoses in the Finnish Hospital Discharge Register was good, and the data provided are suitable for use in further register-based studies of tic disorders.

Epilepsy among children and adolescents with autism spectrum disorders: a population-based study.

The present population-based study examines associations between epilepsy and autism spectrum disorders (ASD). The cohort includes register data of 4,705 children born between 1987 and 2005 and diagnosed as cases of childhood autism, Asperger's syndrome or pervasive developmental disorders--not otherwise specified. Each case was matched to four controls by gender, date of birth, place of birth, and residence in Finland. Epilepsy was associated with ASD regardless of the subgroup after adjusting for covariates. The associations were stronger among cases with intellectual disability, especially among females. Epilepsy's age at onset was similar between the cases and controls regardless of the ASD subgroup. These findings emphasize the importance to examine the neurodevelopmental pathways in ASD, epilepsy and intellectual disability.