Cri du chat syndrome is characterized by cat-like cry, facial dysmorphisms, 
microcephaly, speech delay, intellectual disability and slow growth rate, which 
are present with variable frequency. The typical cri du chat syndrome, due to 
5p15.2 deletion, includes severe intellectual disability, facial dysmorphisms, 
neonatal hypotonia and pre- and post-natal growth retardation, whereas more 
distal deletions in 5p15.3 lead to cat-like cry and speech delay and produce the 
clinical picture of the atypical cri du chat syndrome, with minimal or absent 
intellectual impairment. In this article we report a three-generation family 
with an unbalanced whole arm translocation between chromosome 5 and 15 and a 
microdeletion of 5.5 Mb involving 5p15.33-32. By reporting the smallest terminal 
deletion of 5p15.3 described so far and by reviewing the literature we discuss 
the genotype/phenotype correlations of the distal region of the cri du chat 
syndrome. The previously described critical region for the speech delay may be 
narrowed down and microcephaly, growth retardation and dysmorphic facial 
features can be included in the phenotypic expression of the atypical cri du 
chat syndrome due to 5p15.3 deletions.