FAMILIAL AGENESIS OF THE CORPUS-CALLOSUM - A NEW FORM

Background. Agenesis of the corpus callosum is generally associated wi th other developmental defects of the cerebrum, Some familial cases ha ve been reported. Cases reports Case n 1. A 6 year-old girl was examin ed because of developmental retardation, first noted at the age of 3 m onths. There was no consanguinity but 2 girls, cousins of the father. died at 17 and 18 years with the same clinical presentation. Our patie nt had seizures at 4 years. At examination, she had microcephaly, dila ted unreactive pupils, and generalized hypotonia. Her IQ was 15. Fundo scopic examination showed optic atrophy and visual evoked potentials w ere abnormal. The EEG showed spike-wave discharges and the CT scan sho wed agenesis of the corpus callosum plus heterotopias of the grey matt er and brain atrophy. The child died at 12 years of age. Case n 2. At 15 month-old girl, sister of case n 1, had shown developmental retarda tion since the age of 4 months. She had microcephaly, dilated unreacti ve pupils, generalized hypotonia. Her IQ was 20. She also had optic at rophy, abnormal visual evoked potentials and a hypsarrhythmic pattern on EEG. The CT scan showed agenesis of corpus callosum plus heterotopi as of the grey matter and brain atrophy. She died at the age of 10 yea rs. Case n 3. This boy, brother of cases 1 and 2, was examined on the first day of life. He had microcephaly and some spike-wave discharges on EEG. The CT scan and MRI showed agenesis of the corpus callosum. He had generalized hypotonia at 5 months with an IQ of 30; he suffered f rom seizures at 18 months. Conclusions. This agenesis of the corpus ca llosum seems to have an autosomal recessive inheritance. The associate d developmental defects are different from those previously reported, suggesting that these cases represent a new form of corpus callosum la ck.