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Research On Clinical Characteristics And Related Copy Number Variation Of Autism

Posted on:2013-12-09Degree:MasterType:Thesis
Country:ChinaCandidate:Y ZhangFull Text:PDF
GTID:2234330395950975Subject:Academy of Pediatrics
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Part OneThe perinatal risk factors and family history of autistic disorder and mental retardation/developmental delay:a case control studyObjective:The study aimed to explore the differences of related family history and perinatal risk factors among autistic disorder and mental retardation/developmental delay and normal development.Methods:A case-control study carried out on three groups:100autistic patients,60mental retardation/developmental delay patients and80healthy controls with normal development. Patients and controls in the three groups were recruited from our hospital. The diagnosis was based on the DSM-IV criteria. For each case, data on number of pregnancies and deliveries, gestational age at birth, mode of delivery, birth weight, maternal conditions during pregnancy, maternal age on pregnancy, perinatal history of hypoxia or asphyxia, family history of language retardation, neuropsychiatric disorders, or other developmental disorders, etc. were collected. We used ANOVA, Rank-sum test and Chi-square test methods for statistical analyses.Results:Both patient groups with autistic disorder and mental retardation/developmental delay had a significantly higher rate of related family history than control group (35.0%VS 6.3%, P<0.001;31.7%VS6.3%, P=0.005). There was no statistical significance between the two patient groups (P=0.362). The rates of maternal conditions during pregnancy were different between three groups (28.00%VS45.00%VS26.25%, χ2=6.635, P=0.036), but there was no statistically significant difference between every pairs of groups in pairwise comparison. Maternal age in autistic group was significantly higher than that of control group (P<0.001). With respect to perinatal history of hypoxia or asphyxia, no significant difference was observed between the three groups, neither were number of previous pregnancies and deliveries, gestational age at birth, mode of delivery and birth weight.Conclusion:1) Patients with autistic disorder and mental retardation/developmental delay have a similar rate of related family history, and are both significantly higher than the normal children;2) Late pregnancy may be a risk factor for autistic disorder;3) There is no sufficient evidence to prove number of pregnancies and deliveries, gestational age at birth, mode of delivery and birth weight associated with autistic disorder and mental retardation. Part Two Risk factors for autistic regression:results of an ambispective cohort studyObjective:(1) To characterize the regression in a cohort of children with regressive and non-regressive autism, including the prevalence, onset age, gender, and the type of previously acquired skills lost during regression, and (2) to examine the correlation between autistic regression and perinatal risk factors, family background, and febrile seizures.Method:According to the specific inclusion criteria,170patients diagnosed with autistic disorder were collected in Department of Child Health Care, Children’s Hospital of Fudan University. We conducted an ambispective cohort study to assess autism regression status of recruited autistic patients and explore the risk factors of autism regression, including perinatal risk factors, family background, and febrile seizures. All data recorded on the case report forms were entered into Epidata3.1databases. The data were analyzed using SPSS statistical software V.11.5. For all variables, we gave risk ratios (RRs) and95%confidence intervals (95%CIs) calculated by the Woolf approach. Then, a multiple logistic regression model was developed, in which the outcome (autistic regression or not) was modeled as a binary variable, and all potential factors associated with autistic regression were included as independent variables.Result:Of the170patients diagnosed with autistic disorder,34patients had a definite history of regression at the end of follow-up. The prevalence of regression in this autistic group is20%. The male-to-female ratio of subjects in the regressive group is16:1. Compared with the non-regressive group’s male-to-female ratio of7:1, males were more prone to experience regression, but with no statistical significance (P=0.371). Regression occurred in67.6%of patients before24months and in88.2%of patients before36months. The mean onset age was23.8months, and the median onset age was20.0months. In the regressive group,76.5%(26/34) subjects lost language and67.6%(23/34) in combination with a non-language skill (social skill or other skills, such as learned motor skill, self-help skills). The extent of regression in1domain (language, social skill, or other skills) is26.5%(9of34) versus73.5%(25of34) in more than one domain. In the univariate analysis, no statistically significant differences were observed between the regressive and non-regressive groups for any of the investigated perinatal factors and family background at a=0.05and a=0.10except the variables of family history of neuropsychiatric disorders. The variables of family history of neuropsychiatric disorders (90%CI=1.14-5.73) and febrile seizures (90%CI=1.02-6.12) are statistically significant with autistic regression at a=0.1. We only included factors that had a statistical significance of a=0.1in the univariate analysis into multiple logistic regression model. In this final model, we found statistically significant correlations between autistic regression and febrile seizures (P=0.025) as well as with family history of neuropsychiatric disorders (P=0.011).Conclusion:The prevalence of regression in autistic disorder in this study is20%, which appears to be lower than western population. This study also suggests that febrile seizures and family history of neuropsychiatric disorders are correlated with autistic regression. Part Three Copy number variation of MECP2gene in patients with autismObjective:Indentify whether the MECP2duplication is present in Chinese patients diagnosed with autism and investigate the clinical manifestations of patients with MECP2duplication and the pedigree.Method:According to the specific inclusion criteria, children with autism were recruited for this study by using AccuCopy technology for detection of copy number variations (CNV) in MECP2. For patients identified as carrying MECP2duplication by AccuCopy, the parents and siblings of whom were also tested and the patients were further verified by AccuCopy. Whole genome CNV analysis was carried out for the family identified as having MECP2duplication using Agilent SurePrint G3Human CGH Microarray1×1M. In addition, for the patients with MECP2duplication, the Wechsler Intelligence Scale and Autism Diagnostic Observation Schedule (ADOS) were performed by clinicians with research reliability. Both parents completed the evaluation of Wechsler Adult Intelligence Scale. The mother also completed Symptom Checklist-90.Result:Forty-seven patients with autism were collected. From this group, we identified a family with two brothers both inheriting a2.2Mb MECP2-containing duplication from their mother. The duplicated region contained54genes and we found that MECP2was by far the gene most associated with autism in this duplicated interval. The ADOS score of the two patients are20and17respectively, well above the cutoff for autistic disorder. Cognitive evaluation showed that the two patients had severe mental retardation. The boys displayed clinical features in common with other patients with MECP2duplications, including mental retardation, autism, lack of speech, hypotonia, unsteadiness of movement and slight dysmorphic features. Both parents scored in the normal range on the Wechsler Adult Intelligence Scale. The mother of the patients had slightly higher scores in somatization, depression, anxiety and psychoticism on completing Symptom Checklist-90and reported sleep disturbances.Conclusion:Our results demonstrate that the patients with MECP2duplications share the same clinical manifestation with previous reports abroad and MECP2duplications are present in Chinese Han autism patient. In addition, female carriers of MECP2duplications may have mental problems, such as anxiety and depression.
Keywords/Search Tags:autistic disorder, mental retardation/developmental delay, perinatal riskfactors, related family historyautistic regression, risk factors, febrile seizures, neuropsychiatricdisordersautism, MECP2duplication, copy number variations, developmentaldelay
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