Leukoencephalopathy associated with 11q24 deletion involving the gene encoding hepatic and glial cell adhesion molecule in two patients

Leukoencephalopathies are heterogeneous entities with white matter abnormalities. Mutations of the gene encoding hepatic and glial cell adhesion molecule (HEPACAM) located on 11q24 are related to one of the leukoencephalopathies: megalencephalic leukoencephalopathy with subcortical cysts type 2 (MLC2). Genomic copy number aberrations were analyzed by microarray comparative hybridization for two patients. One patient who presented with abnormal intensity of the white matter had been previously been diagnosed with the typical genotype and phenotype of Jacobsen syndrome due to an 11q subtelomere deletion, which was further characterized here. In a second patient who exhibited the characteristic finding of leukoencephalopathy, an interstitial deletion of 11q24 was also identified. HEPACAM was involved in both deletions. We therefore suggest that haploinsufficiency of HEPACAM, a gene previously associated with the features of MLC2 and located on the overlapping deletion region between the two patients, might be related to the observed white matter abnormalities.