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Autism spectrum disorders (ASD) are a heterogeneous group of neurodevelopmental disabilities with various etiologies, but with a heritability estimate of more than 90%. Although the strong correlation between autism and genetic factors has been long established, the exact genetic background of ASD remains unclear. A number of genetic syndromes manifest ASD at higher than expected frequencies compared to the general population. These syndromes account for more than 10% of all ASD cases and include tuberous sclerosis, fragile X, Down, neurofibromatosis, Angelman, Prader-Willi, Williams, Duchenne, etc. Clinicians are increasingly required to recognize genetic disorders in individuals with ASD, in terms of providing proper care and prognosis to the patient, as well as genetic counseling to the family. Vice versa, it is equally essential to identify ASD in patients with genetic syndromes, in order to ensure correct management and appropriate educational placement. During investigation of genetic syndromes, a number of issues emerge: impact of intellectual disability in ASD diagnoses, identification of autistic subphenotypes and differences from idiopathic autism, validity of assessment tools designed for idiopathic autism, possible mechanisms for the association with ASD, etc. Findings from the study of genetic syndromes are incorporated into the ongoing research on autism etiology and pathogenesis; different syndromes converge upon common biological backgrounds (such as disrupted molecular pathways and brain circuitries), which probably account for their comorbidity with autism. This review paper critically examines the prevalence and characteristics of the main genetic syndromes, as well as the possible mechanisms for their association with ASD.

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Autism is a severe childhood disorder already presenting in the first 3 years of life and, therefore, strongly correlated with neurodevelopmental alterations in prenatal, as well as postnatal period. Neurotransmitters hold a pivotal role in development by providing the stimulation needed for synapses and neuronal networks to be formed during the critical period of neuroplasticity. Aberrations of the serotonergic system modify key processes in the developing brain and are strongly implicated in the pathophysiology of developmental disorders. Evidence for the role of serotonin in autism emerges from neuropathological, imaging and genetic studies. Due to its developmental arrest, autism requires early intervention that would, among others, target the disrupted serotonergic system and utilize brain plasticity to elicit clinically important brain changes in children.

BackgroundIdiopathic epilepsies and epileptic syndromes predominate childhood and adolescence epilepsy. The aim of the present study was to investigate the clinical course and outcome of idiopathic childhood epilepsy and identify variables determining both early and long-term prognosis.MethodsWe followed 303 children with newly diagnosed idiopathic epilepsy aged 1–14 years old, both prospectively and retrospectively. Outcome was defined at one, 2 and 4 years of follow-up, as well as at the end of the study period for all patients. Based on the data collected, patients were classified in four patterns of clinical course: “excellent”, “improving”, “relapsing” and “poor”. Variables defined at intake and after the initial year of treatment were analyzed for their prognostic relevance towards the clinical course and outcome of the patients.ResultsThe mean age at seizure onset was 6,7 years and the mean duration of follow-up was 8,3 years (range 2,0-22,0,SD 4,24). During the initial year of treatment, 70,3% of patients were seizure-free. The course of epilepsy was “excellent” in 53,1% of the subjects, “improving” in 22,8%, “relapsing” in 22,1% whereas only 6 children with idiopathic epilepsy (2%) had a “poor” clinical course exhibiting drug-resistance. After multivariate analysis, variables predictive of a poor initial response to therapy were early seizure onset, multiple seizure types and history of status epilepticus. At the end of follow-up, early response to treatment was of significant positive predictive value, while the presence of multiple seizure types and the history of migraine had a negative impact on prognosis.ConclusionsIn the vast majority of children, the long-term prognosis of idiopathic epilepsy is favorable. More than half of the patients attain seizure freedom immediately and their clinical course is considered “excellent”. About one fifth exhibit either an improving or a fluctuating course. Early seizure onset, multiple seizure types and status epilepticus are predictive of an initial poor response to treatment in children with idiopathic epilepsy. Initial non-response to treatment, multiple seizure types and history of migraine are determinants of a less favorable final outcome after long-term follow-up.