Microarray-based comparative genomic hybridization (aCGH) between basic research and clinical diagnostic

In the vast spectrum of human pathology, a significant proportion is represented by genetic disorders. To elucidate the mechanisms leading to disease, various approaches have been used: G-banded karyotyping and FISH allow the survey of the entire genome for large aberrations or analysis of pre-defined segments, while sequencing detects nucleotide alterations with the prior requirement of knowing which DNA segment to address. The last two decades have seen the rise of another generation of investigative methods, such as aCGH, which inquire the condition of the whole genome at sequence level; starting as a research instrument, aCGH is increasingly regarded as a powerful diagnostic tool for clinical use. As an example of its utility in the diagnostic of mental retardation, we present three cases where aCGH contributed to the identification and refinement of the precise genetic aberrations