Cri-du-chat syndrome is a chromosomal disorder caused by a deletion of the short 
arm of chromosome 5. The disease severity, levels of intellectual and 
developmental delay, and patient prognosis have been related to the size and 
position of the deletion. Aiming to establish genotype-phenotype correlations, 
we applied array-CGH to evaluate six patients carrying cytogenetically detected 
deletions of the short arm of chromosome 5 who were followed at a genetics 
community service. The patients' cytogenetic and clinical profiles were 
reevaluated. A database review was performed to predict additional genes and 
regulatory elements responsible for the characteristic phenotypic and behavioral 
traits of this disorder. Array-CGH analysis allowed for delineation of the 
terminal deletions, which ranged in size from approximately 11.2 Mb to 28.6 Mb, 
with breakpoints from 5p15.2 to 5p13. An additional dup(8)(p23) (3.5 Mb), 
considered to be a benign copy number variation, was also observed in one 
patient. The correlation coefficient value (ρ = 0.13) calculated indicated the 
presence of a weak relationship between developmental delay and deletion size. 
Genetic background, family history, epigenetic factors, quantitative trait locus 
polymorphisms, and environmental factors may also affect patient phenotype and 
must be taken into account in genotype-phenotype correlations.