Lissencephaly associated with congenital hypomyelinating and axonal neuropathy.

The authors describe an 11-year-old male with severe mental retardation, hypotonia, and arthrogryposis, with both type I lissencephaly and a congenital peripheral neuropathy, probably hypomyelinating with axonal involvement. To the best of the authors' knowledge, this is the first report involving the co-occurrence of these two developmental disorders. A viral, metabolic, or nutritional insult acting throughout the period of migration and myelination or a contiguous gene linkage are possible explanations for this disorder.