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, café-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 café-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.