X-Linked Lissencephaly With Absent Corpus Callosum and Abnormal Genitalia

X-linked lissencephaly with absent corpus callosum and abnormal genitalia (XLAG) is caused by a mutation in the ARX gene. We herein report the clinical course of siblings with XLAG with a splicing mutation in ARX. Seizures were observed in utero. Cerebral atrophy was progressive postnatally, and fetal echoencephalography indicated that the atrophy might have started in the prenatal period. They had a typical phenotype, except that the genital abnormality of the younger brother was not remarkable. A portal-systemic shunt that has not been reported in cases with XLAG was seen in the older brother. The siblings had the different complications and severity of disease in spite of possessing the same mutation.