A case of Miller-Dieker syndrome in a family with neurofibromatosis type I

The Miller-Dieker syndrome (type I lissencephaly) is a neuronal migration disorder which is associated with microdeletions in the short arm of chromosome 17, Neurofibromatosis type I(NF1) is an autosomal dominant condition associated with mutations in the long arm of chromosome 17, and characterised by neurofibromas, cafe-au-lait spots and axillary freckling. The neonatal period for a female infant born at 39 weeks gestation by emergency Caesarean section was complicated by frequent epileptic seizures as well as hypotonia. A computed tomography scan revealed evidence of lissencephaly, and chromosomal analysis showed a microdeletion on the short arm of chromosome 17 (17p13.3), confirming the diagnosis as Miller-Dieker syndrome. The child died at the age of 4 years and examination of the brain confirmed lissencephaly with a thickened cortex, deficient white matter, and grey matter heteropias. The mother had cafe-au-lait spots, and axillary freckling. In addition, the mother's and maternal grandmother's genetic analysis showed identical mutations in the neurofibromatosis I gene on the long arm of chromosome 17, confirming the diagnosis of NF1. The child did not possess the mutation. This case illustrates a rare neuronal migration disorder appearing in a child from a family with a history of NF1.