Objective: To describe 3 sisters with brain periventricular heterotopia and peculiar dysmorphic features as a probable X-linked dominant trait.
Design: Clinical, laboratory, neurophysiological, and brain imaging data were studied.
Setting: Research institute for mental retardation.
Patients: The 3 sisters had mental retardation, drug-resistant epilepsy, gray matter heterotopia, and peculiar malformations (low nasal bridge, upslanting palpebral fissures, palpebral edema, attached hypoplastic earlobes, thickened calvaria, rectal fibrovascular polyps, urinary tract anomalies, and increased foot length). The patients were 35, 30, and 25 years old and belonged to a sibship of 6, born of nonconsanguineous healthy parents.
Conclusion: The 3 patients constitute a well-defined clinical entity not previously described of a probable X-linked dominant nature.