Subcortical laminar heterotopia in two sisters and their mother: MRI, clinical findings and pathogenesis.

MR imaging, clinical data and underlying pathogenesis of subcortical laminar heterotopia (SCLH), also known as band heterotopia, in two sisters and their mother are presented. On MR imaging a different degree of SCLH was found in all three affected family-members. The inversion recovery sequence was considered most useful in the demonstration of the heterotopic band of gray matter and the assessment of cortical thickness. The younger sister presented with epileptic seizures at the age of five months and a delayed achievement of developmental milestones. The older sister of seven years had epileptic seizures since the age of one year, and developmental delay. Their mother has only had one seizure-like episode at the age of 39. Her psychomotor development had been normal. Investigation of DNA samples of the three female family-members revealed a mutation in the X-linked doublecortin gene. Within families with band heterotopia, this gene has also been related to male family members with lissencephaly.