Another Italian family with mandibuloacral dysplasia: why does it seem more frequent in Italy?

We describe three patients (one female and two males in a sibship of 11) with mandibuloacral dysplasia. Only eight families have been reported previously, and of these, four were of Italian origin. The phenotypic spectrum of the condition is delineated and its variability is stressed. The observation of three affected members of both sexes with normal parents supports the hypothesis of autosomal recessive inheritance. The reasons for the high frequency of the condition in Italy are discussed; a local selective advantage for heterozygotes and founder effect might be involved.