Three infant cases of Smad interacting protein 1 (SIP1) abnormalities with epilepsy

Three infants (two males and one female) with Smad interacting protein 1 (SIP1) abnormalities characterized by severe mental retardation, delayed motor development and distinct facial features are presented. All 3 patients had epilepsy, and 1 had Hirschsprung disease. The patients developed complex partial seizures at the age of 3 years, 4 years 1 month and 2 years 1 month, respectively. The main clinical symptoms of complex partial seizures in 2 patients were nausea and/or vomiting. In 2 patients, epilepsy was preceded by febrile convulsion. All three had status epilepticus with or without fever. Enlargement of the inferior horn of the lateral ventricle and hypoplasia of the corpus callosum were detected by MRI in two patients. Typical EEGs in these patients were normal at first, followed by presentation of focal spikes, and finally continuous bilateral frontal dominant diffuse high voltage slow waves or spike-and-wave complexes at age 2 years 10 months, 5 years 3 months and 3 years 3 months, respectively. When we encounter a patient with characteristic face, mental retardation, complex partial seizures and specific EEG findings, we should consider a diagnosis of SIP1 abnormalities and follow the patients carefully, bearing in mind the possibility of status epilepticus.