Paul A. Law

Familial Clustering of Autoimmune Disorders and Evaluation of Medical Risk Factors in Autism

Autism is an age-dependent neurologic disorder that is often associated with autoimmune disorders in the patients relatives. To evaluate the frequency of autoimmune disorders, as well as various prenatal and postnatal events in autism, we surveyed the families of 61 autistic patients and 46 healthy controls using questionnaires. The mean number of autoimmune disorders was greater in families with autism; 46% had two or more members with autoimmune disorders. As the number of family members with autoimmune disorders increased from one to three, the risk of autism was greater, with an odds ratio that increased from 1.9 to 5.5, respectively. In mothers and first-degree relatives of autistic children, there were more autoimmune disorders (16% and 21%) as compared to controls (2% and 4%), with odds ratios of 8.8 and 6.0, respectively. The most common autoimmune disorders in both groups were type 1 diabetes, adult rheumatoid arthritis, hypothyroidism, and systemic lupus erythematosus. Forty-six percent of the autism group reported having relatives with rheumatoid diseases, as compared to 26% of the controls. Prenatal maternal urinary tract, upper respiratory, and vaginal infections; asphyxia; prematurity, and seizures were more common in the autistic group, although the differences were not significant. Thirty-nine percent of the controls, but only 11% of the autistic group, reported allergies. An increased number of autoimmune disorders suggests that in some families with autism, immune dysfunction could interact with various environmental factors to play a role in autism pathogenesis. (J Child Neurol 1999;14:388-394).

Sibling Recurrence and the Genetic Epidemiology of Autism

OBJECTIVEnAlthough the symptoms of autism exhibit quantitative distributions in nature, estimates of recurrence risk in families have never previously considered or incorporated quantitative characterization of the autistic phenotype among siblings.nnnMETHODnThe authors report the results of quantitative characterization of 2,920 children from 1,235 families participating in a national volunteer register, with at least one child clinically affected by an autism spectrum disorder and at least one full biological sibling.nnnRESULTSnA traditionally defined autism spectrum disorder in an additional child occurred in 10.9% of the families. An additional 20% of nonautism-affected siblings had a history of language delay, one-half of whom exhibited autistic qualities of speech. Quantitative characterization using the Social Responsiveness Scale supported previously reported aggregation of a wide range of subclinical (quantitative) autistic traits among otherwise unaffected children in multiple-incidence families and a relative absence of quantitative autistic traits among siblings in single-incidence families. Girls whose standardized severity ratings fell above a first percentile severity threshold (relative to the general population distribution) were significantly less likely to have elicited community diagnoses than their male counterparts.nnnCONCLUSIONSnThese data suggest that, depending on how it is defined, sibling recurrence in autism spectrum disorder may exceed previously published estimates and varies as a function of family type. The results support differences in mechanisms of genetic transmission between simplex and multiplex autism and advance current understanding of the genetic epidemiology of autism spectrum conditions.

A unified genetic theory for sporadic and inherited autism

Autism is among the most clearly genetically determined of all cognitive-developmental disorders, with males affected more often than females. We have analyzed autism risk in multiplex families from the Autism Genetic Resource Exchange (AGRE) and find strong evidence for dominant transmission to male offspring. By incorporating generally accepted rates of autism and sibling recurrence, we find good fit for a simple genetic model in which most families fall into two types: a small minority for whom the risk of autism in male offspring is near 50%, and the vast majority for whom male offspring have a low risk. We propose an explanation that links these two types of families: sporadic autism in the low-risk families is mainly caused by spontaneous mutation with high penetrance in males and relatively poor penetrance in females; and high-risk families are from those offspring, most often females, who carry a new causative mutation but are unaffected and in turn transmit the mutation in dominant fashion to their offspring.

Characteristics and concordance of autism spectrum disorders among 277 twin pairs

OBJECTIVESnTo examine patterns of autism spectrum disorder (ASD) inheritance and other features in twin pairs by zygosity, sex, and specific ASD diagnosis.nnnDESIGNnCross-sectional study.nnnSETTINGnInternet-based autism registry for US residents.nnnPARTICIPANTSnSurvey results from 277 twin pairs (210 dizygotic [DZ] and 67 monozygotic [MZ]) aged 18 years or younger with at least 1 affected twin.nnnMAIN EXPOSURESnZygosity and sex.nnnOUTCOME MEASURESnConcordance within twin pairs of diagnosis, natural history, and results from standardized autism screening.nnnRESULTSnPairwise ASD concordance was 31% for DZ and 88% for MZ twins. Female and male MZ twins were 100% and 86% concordant, respectively, and DZ twin pairs with at least 1 female were less likely to be concordant (20%) than were male-male DZ twin pairs (40%). The hazard ratio for ASD diagnosis of the second twin after a first-twin diagnosis was 7.48 for MZ vs DZ twins (95% confidence interval, 3.8-14.7). Affected DZ individual twins had an earlier age at first parental concern and more frequent diagnoses of intellectual disability than did MZ twins; MZ twins had a higher prevalence of bipolar disorder and Asperger syndrome and higher concordance of the latter. Results of autism screening correlated with parent-reported ASD status in more than 90% of cases.nnnCONCLUSIONSnOur data support greater ASD concordance in MZ vs DZ twins. Overall higher functioning, psychiatric comorbidity, and Asperger syndrome concordance among affected MZ vs DZ twins may also suggest differential heritability for different ASDs. For families in which one MZ twin is diagnosed with ASD, the second twin is unlikely to receive an ASD diagnosis after 12 months. In addition, Internet parent report of ASD status is valid.

Validation of proposed DSM-5 criteria for autism spectrum disorder.

OBJECTIVEnThe primary aim of the present study was to evaluate the validity of proposed DSM-5 criteria for autism spectrum disorder (ASD).nnnMETHODnWe analyzed symptoms from 14,744 siblings (8,911 ASD and 5,863 non-ASD) included in a national registry, the Interactive Autism Network. Youth 2 through 18 years of age were included if at least one child in the family was diagnosed with ASD. Caregivers reported symptoms using the Social Responsiveness Scale and the Social Communication Questionnaire. The structure of autism symptoms was examined using latent variable models that included categories, dimensions, or hybrid models specifying categories and subdimensions. Diagnostic efficiency statistics evaluated the proposed DSM-5 algorithm in identifying ASD.nnnRESULTSnA hybrid model that included both a category (ASD versus non-ASD) and two symptom dimensions (social communication/interaction and restricted/repetitive behaviors) was more parsimonious than all other models and replicated across measures and subsamples. Empirical classifications from this hybrid model closely mirrored clinical ASD diagnoses (90% overlap), implying a broad ASD category distinct from non-ASD. DSM-5 criteria had superior specificity relative to DSM-IV-TR criteria (0.97 versus 0.86); however sensitivity was lower (0.81 versus 0.95). Relaxing DSM-5 criteria by requiring one less symptom criterion increased sensitivity (0.93 versus 0.81), with minimal reduction in specificity (0.95 versus 0.97).nnnCONCLUSIONSnResults supported the validity of proposed DSM-5 criteria for ASD as provided in Phase I Field Trials criteria. Increased specificity of DSM-5 relative to DSM-IV-TR may reduce false positive diagnoses, a particularly relevant consideration for low base rate clinical settings. Phase II testing of DSM-5 should consider a relaxed algorithm, without which as many as 12% of ASD-affected individuals, particularly females, will be missed. Relaxed DSM-5 criteria may improve identification of ASD, decreasing societal costs through appropriate early diagnosis and maximizing intervention resources.

Lamotrigine therapy for autistic disorder: a randomized, double-blind, placebo-controlled trial.

In autism, glutamate may be increased or its receptors up-regulated as part of an excitotoxic process that damages neural networks and subsequently contributes to behavioral and cognitive deficits seen in the disorder. This was a double-blind, placebo-controlled, parallel group study of lamotrigine, an agent that modulates glutamate release. Twenty-eight children (27 boys) ages 3 to 11 years (M = 5.8) with a primary diagnosis of autistic disorder received either placebo or lamotrigine twice daily. In children on lamotrigine, the drug was titrated upward over 8 weeks to reach a mean maintenance dose of 5.0 mg/kg per day. This dose was then maintained for 4 weeks. Following maintenance evaluations, the drug was tapered down over 2 weeks. The trial ended with a 4-week drug-free period. Outcome measures included improvements in severity and behavioral features of autistic disorder (stereotypies, lethargy, irritability, hyperactivity, emotional reciprocity, sharing pleasures) and improvements in language and communication, socialization, and daily living skills noted after 12 weeks (the end of a 4-week maintenance phase). We did not find any significant differences in improvements between lamotrigine or placebo groups on the Autism Behavior Checklist, the Aberrant Behavior Checklist, the Vineland Adaptive Behavior scales, the PL-ADOS, or the CARS. Parent rating scales showed marked improvements, presumably due to expectations of benefits.

Effect of topical treatment with skin barrier-enhancing emollients on nosocomial infections in preterm infants in Bangladesh: a randomised controlled trial.

BACKGROUNDnInfections and complications of prematurity are main causes of neonatal mortality. Very low birthweight premature infants have compromised skin barrier function, and are at especially high risk for serious infections and mortality. Our aim was to ascertain whether topical application of emollients to enhance skin barrier function would prevent nosocomial infections in this population.nnnMETHODSnWe randomly assigned infants born before week 33 of gestation after admission to Dhaka Shishu Hospital, Bangladesh, to daily massage with sunflower seed oil (n=159) or Aquaphor (petrolatum, mineral oil, mineral wax, lanolin alcohol; n=157). We then compared incidence of nosocomial infections among infants in these two groups with an untreated control group (n=181) by an intention-to-treat analysis.nnnFINDINGSn20 patients in the control group, and 22 in each of the treatment groups left the hospital early, but were included in the final analysis. Overall, infants treated with sunflower seed oil were 41% less likely to develop nosocomial infections than controls (adjusted incidence rate ratio [IRR] 0.59, 95% CI 0.37-0.96, p=0.032). Aquaphor did not significantly reduce the risk of infection (0.60, 0.35-1.03, p=0.065). No adverse events were seen.nnnINTERPRETATIONnOur findings confirm that skin application of sunflower seed oil provides protection against nosocomial infections in preterm very low birthweight infants. The low cost, availability, simplicity, and effect of treatment make it an important intervention for very low birthweight infants admitted to hospital in developing countries.

Topically applied sunflower seed oil prevents invasive bacterial infections in preterm infants in Egypt: a randomized, controlled clinical trial.

Background: Because the therapeutic options for managing infections in neonates in developing countries are often limited, innovative approaches to preventing infections are needed. Topical therapy with skin barrier-enhancing products may be an effective strategy for improving neonatal outcomes, particularly among preterm, low birth weight infants whose skin barrier is temporarily but critically compromised as a result of immaturity. Methods: We tested the impact of topical application of sunflower seed oil 3 times daily to preterm infants <34 weeks gestational age at the Kasr El-Aini neonatal intensive care unit at Cairo University on skin condition, rates of nosocomial infections and mortality. Results: Treatment with sunflower seed oil (n = 51) resulted in a significant improvement in skin condition (P = 0.037) and a highly significant reduction in the incidence of nosocomial infections (adjusted incidence ratio, 0.46; 95% confidence interval, 0.26–0.81; P = 0.007) compared with infants not receiving topical prophylaxis (n = 52). There were no reported adverse events as a result of topical therapy. Conclusions: Given the low cost (~

Verification of Parent-Report of Child Autism Spectrum Disorder Diagnosis to a Web-Based Autism Registry

.20 for a course of therapy) and technologic simplicity of the intervention and the effect size observed in this study, a clinical trial with increased numbers of subjects is indicated to evaluate the potential of topical therapy to reduce infections and save newborn lives in developing countries.

Psychotropic Medication Use Among Children With Autism Spectrum Disorders Enrolled in a National Registry, 2007–2008

Growing interest in autism spectrum disorder (ASD) research requires increasingly large samples to uncover epidemiologic trends; such a large dataset is available in a national, web-based autism registry, the Interactive Autism Network (IAN). The objective of this study was to verify parent-report of professional ASD diagnosis to the registry’s database via a medical record review on a sample of IAN Research participants. Sixty-one percent of families agreed to participate; 98% (nxa0=xa0116) of whom provided documentation verifying a professionally diagnosed ASD. Results of this study suggest that information collected from parents participating in IAN Research is valid, participants can be authenticated, and that scientists can both confidently use IAN data and recruit participants for autism research.