Severely retarded children with microcephaly and dysmorphic facies and lissencephaly as well as children with isolated lissencephaly.
Miller-Dieker-Lissencephaly Syndrome, Microdeletion 17p13.3
Lissencephaly
Clinical Features
The Miller-Dieker syndrome is characterized by severe lissencephaly with agyria or pachygyria and widened ventricles. NMR may show additional abnormalities such as aplasia or hypoplasia of the corpus callosum. The severe brain anomaly leads to intrauterine growth retardation, reduced fetal movements and polyhydramnion. Neurological signs are variable; at birth, infants may show hypotonia, opisthotonus or spasticity. Children of older age usually show severe motor and mental retardation as well as facial dysmorphic features (prominent forehead with bitemporal hollowing).
Genetic Information
The Miller-Dieker syndrome is characterized by a microdeletion in the short arm of chromosome 17 (17p13.3) leading to partial monosomy 17p13.3. This microdeletion is found in around 90% of the affected individuals. Similar to other microdeletion syndromes these are mostly sporadic cases. Lissencephaly may alternatively be caused by a mutation in the LIS1 gene on chromosome 17 (17p13.3). In addition, there is a X-chromosomal form of lissencephaly with underlying mutations in the DCX gene (Xq22.3-q23).
Prevalence
1 : 50 000
Diagnostic
Indication
Method
FISH or MLPA analysis
Karyotyping
Sample Requirement
2 - 5 ml of heparinised blood
2 - 4 ml of EDTA blood
Duration
1 week
OMIM