Diamond-Blackfan anaemia in the Italian population

Diamond-Blackfan anaemia (DBA) is a congenital disease characterized by def ective erythroid progenitor maturation; 30% of patients have congenital mal formations. The link between these malformations and defective erythropoies is is unclear: a defect in a molecule acting both on embryo development and haemopoiesis has been proposed, Inheritance is autosomal dominant in most familial cases, but recessive families have also been reported. Many cases are sporadic. A DBA locus has been mapped on chromosome 19q13.2 (Gustavsson et al, 1997), but several families unlinked to this locus have also been r eported (Gustavsson et al, 1998). This paper presents clinical, epidemiological and molecular data for DBA in the Italian population, Segregation analysis of 19q markers in patients wi th DBA showed exclusion of this locus in 5/12 families with inherited DBA. There was evidently locus heterogeneity for DBA in this population. A new m icrodeletion was identified in one patient. Other families, in which DBA se gregates concordantly with the 19q critical region, suggest incomplete pene trance and expressivity of the DBA gene.