[Marfan's syndrome--application of revised criteria and differential diagnosis in clinical practice]

To design a system of diagnostic criteria that would allow us to differentiate benign articular hyperelasticity from Marfan's or Ehlers-Danlos syndromes and, on the basis of clinical, anthropometric, radiological, biochemical and densitometric findings, their specificity and statistical significance, to draw definitive conclusions for clinical practice.

A total of 240 patients who presented with the diagnosis of one of connective tissue disorders were included. They all were examined and, in 182 of them, the findings were completed to meet the criteria required by differential diagnosis.

Revised criteria were used for Marfan's syndrome (MFS), Ehlers-Danlos syndrome (EDS), osteogenesis imperfecta (OI), juvenile idiopathic osteoporosis (JIO), cutis laxa (CL) or benign articular hyperelasticity (BAH). All patients provided their medical histories, and underwent clinical, radiological, anthropometric, echocardiographic and biochemical examinations, including that for markers of bone formation and resorption. The anteroposterior bulb length was assessed by ultrasonography; densitomery was performed and vital capacity was measured. All data obtained were processed by computer software and the definitive diagnosis was established.

Out of 82 patients initially diagnosed with MFS, only 43 (52.4%) met the revised criteria; of the 53 EDS patients initially, 30 (56.6%) met the revised criteria. Four patients who had been referred to us with MFS were found to meet the criteria for EDS (two) and OI (two). Out of 35 patients with OI, 22 (62.8%) met the diagnostic criteria. All 24 patients with BAH were confirmed to have this diagnosis. On the basis of the revised criteria, none of the patients was diagnosed as having JIO or CL.

The authors compare their results of decreased levels of procollagen I, the occurrence of scoliosis or acetabular protrusion and reduced vital capacity with the relevant reports in the literature.

The specific criteria for Marfan's syndrome include lens dislocation or an anteroposterior bulb axis longer than 24 mm, ascending aortic dilatation, greater body height and the ratio of lower extremities to the body and that of arm-span to height higher than 1.05. However, some criteria, such as the metacarpal-phalangeal index, are not characteristic of Marfan's syndrome only and, therefore, cannot be regarded as a major diagnostic feature of this disorder.