Congenital bone marrow failure syndromes. The last 20 years by the example of congenital neutropenia

Congenital bone marrow failure syndromes are rare diseases characterised by a reduction of mature blood cells (erythrocytes, platelets, neutrophils). Examples of such disorders include congenital aplastic anemia (Fanconi anemia), congenital hypoplastic anemia (Diamond-Blackfan anemia), congenital neutropenias (Kostmann syndrome, cyclic neutropenia, Shwachman-Diamond syndrome and others), and congenital thrombocytopenias (TAR syndrome, amegacaryocytic thrombocytopenia). In Germany the prevalence of congenital bone marrow failure syndromes can be estimated to be 10/1,000,000 children and adolescents. Although rare, these diseases contributed significantly to the current knowledge on normal haematopoiesis. The documentation of rare diseases by patient registries and the cooperation of clinical centres within networks are most important for the resolution of such disorders. In the following, congenital neutropenia will be presented as an example: Until the 1980s congenital neutropenia could only be classified clinically. Few cases had been reported in the literature. All subtypes were therefore collected under the general term "congenital neutropenia" The establishment of an international network of experts and the long-term documentation of the courses of disease in a common database allowed for statistically workable data in response to therapy, secondary diagnoses and the long-term prognosis. A close cooperation with scientists finally led to the characterisation of genetically different disorders with common pathomechanisms.