Polymicrogyria in a child with inv dup del(9p) and 22q11.2 microduplication

Polymicrogyria (PMG) is a relatively common malformation of the cortex for which the pathogenesis remains poorly understood. Both acquired and genetic causes are known, and to date more than 70 cases of PMG have been associated with chromosomal abnormalities. Here we report on a 12-year-old girl presenting with asymmetrical PMG predominantly affecting the right occipital lobe. She was the only child of consanguineous parents. At 7 years of age she was referred for mental retardation with speech delay and seizures. Cytogenetic studies of the patient revealed an inverted 9p duplication/deletion and bacterial artificial chromosomes (BACs)-array also showed a 22q11.2 microduplication confirmed by quantitative PCR. This case is of interest in the search for candidate genes and emphasizes the importance of the 22q11 region in PMG. It also highlights the efficiency of BACs-array in detecting complex rearrangements.