Wolf-Hirschhorn syndrome (WHS) is a rare develop mental disorder caused by a partial deletion of the short arm of chromosome 4 (4p-). The main phenotypic charac teristics of WHS are: intrauterine growth retardation, men tal retardation, typical facial dysmorphism, microcephaly and midline fusion defects (cleft lip or palate, cardiac septal defects). Other abnormalities, such as agenesis of the corpus callosum, dysplastic kidneys, iris coloboma and skeletal abnormalities have occasionally been described.

We describe two female newborn babies with a 4p deletion, who have a majority of the main phenotypic features of WHS. Prenatal diagnosis of the syndrome is very important, because dysmorphologic features are asso ciated with profound mental retardation. Postnatal recogni tion of the syndrome requires genetic counseling of the parents and supportive multidisciplinary treatment.

Key words: Wolf-Hirschhorn syndrome (WHS); Chromosome 4; Deletion.