Chromosomal map of human brain malformations

The etiology of most central nervous system (CNS) malformations remains unknown. We have utilized the fact that autosomal chromosome aberrations are commonly associated with CNS malformations to identify new causative gene loci. The human cytogenetic database, a computerized catalog of the clinical phenotypes associated with cytogenetically detectable human chromosome aberrations, was used to identify patients with 14 selected brain malformations including 541 with deletions, and 290 carrying duplications. These cases were used to develop an autosomal deletion and duplication map consisting of 67 different deleted malformation associated bands (MABs) in 55 regions and 88 different duplicated MABs in 36 regions; 31 of the deleted and 8 duplicated MABs were highly significantly associated (P < 0.001). All holoprosencephaly MABs found in the database contained a known HPE gene providing some level of validation for the approach. Significantly associated MABs are discussed for each malformation together with the published data about known disease-causing genes and reported malformation-associated loci, as well as the limitations of the proposed approach.