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Background: Autonomic dysfunction is common in children with Rett syndrome. They usually manifest with agitation, persistent screaming, constipation, gastroesophageal reflux, aerophagia, hyperventilation, and breath-holding episodes. Cardiovascular autonomic dysfunction may result in fatal a arrhythmia. Many of these events are mistaken for seizures and treated with antiepileptics.Methods: The present study was conducted in a tertiary care teaching hospital in north India for more than a six month period. MeCP2 mutation positive, 24 cases with Rett syndrome and 24 age-matched healthy girls were evaluated for cardiovascular autonomic dysfunction (heart rate variability, head-up tilt test, and cold pressor test).Results: The mean age was 9.06 years (±3.4) and 9.75 years (±3.13) for patients and control subjects, respectively. The heart rate variability contributed independently by parasympathetic and sympathetic nervous system was significantly reduced in cases compared with control subjects (P = 0.033 and P = 0.001, respectively). There was significant sympathovagal imbalance with sympathetic overactivity in cases compared with control subjects (P = 0.001). The mean longest QTc interval was significantly prolonged in cases compared with control subjects (P = 0.001). Cold pressor test and head-up tilt test could be done in 16 Rett syndrome patients (because of poor cooperation) and in all 24 control subjects. The change in blood pressure during cold pressor test and head-up tilt test was not significantly different in cases and control subjects.Conclusions: Children with Rett syndrome exhibited significant cardiovascular autonomic dysfunction in the form of sympathetic overactivity, parasympathetic underactivity, and sympathovagal imbalance. These findings have potentially important therapeutic- and outcome-related implications. [ABSTRACT FROM AUTHOR]

Mutations in the MLC1 gene cause megalencephalic leukoencephalopathy with subcortical cysts. We sought to identify mutations in the MLC1 gene, to evaluate the genotype-phenotype correlation, and to develop a strategy for diagnosing Indian patients with megalencephalic leukoencephalopathy. Forty patients were enrolled. We developed a rapid restriction fragment length polymorphism method to screen a common mutation, c.135_136insC. Rare and novel mutations were screened by conformation-sensitive gel electrophoresis, followed by sequencing. Three previously reported and two novel mutations were identified in 37 patients. The presence of the c.135_136insC mutation in 29 patients of the Agarwal community suggests a founder effect. The mutation c.959C>A was evident in four patients, and appears to be the second commonest mutation. Genotype could not predict phenotype. We recommend screening for the commonest mutation (c.135_136insC), followed by the next commonest mutation (c.959C>A), and then other rare mutations, using conformation-sensitive gel electrophoresis analysis or direct sequencing. [ABSTRACT FROM AUTHOR]