Background Epilepsy with intellectual disability limited to females (Epileptic encephalopathy, early infantile, 9; EIEE9) is a rare early infantile epileptic encephalopathy characterized by an unusual X-linked inheritance: females with heterozygous mutations are affected, while hemizygous males are not. Case presentation We describe the clinical and molecular characteristics of 2 Russian patients with EIEE9 (females, ages 3 years and 7 years). In these patients seizures developed at the age of 3 years. Additionally, for our patients and for cases described in the literature we searched for a possible relationship between the type and localization of the mutation and the EIEE9 clinical phenotype. Conclusions We identified two novel PCDH19 mutations in EIEE9 patients: a missense mutation in exon 1 (c.1236C > A, p.Asp412Glu) and a frameshift in exon 3 (c.2386_2387insGTCT, p.Thr796fs). We conclude that the age of seizure onset and the presence of intellectual disability may depend not on the type and localization of PCDH19 mutations, but on the X-inactivation status. The study also highlights the need to screen for EIEE9 among young female epilepsy patients.

This report addresses behavioral abnormalities in children with cerebellar anomalies demonstrated on MRI scans. Published data are presented showing an interaction between cerebellar pathology and early childhood autism. The cerebellum is involved not only in movement coordination, but also in social adaptation and verbal communication. The genes expressed in the cerebellum during childhood are identical to those expressed in the hippocampus. We have observed 20 children with MRI-identified agenesis of the cerebellar vermis and behavioral abnormalities; children were aged 3-15 (mean 7.05) years and there were 12 males and eight females. A variety of autistic characteristics were identified in these children.