Validity of metacarpal-index in children with Marfansyndrome and children with constitutional tall stature

Abstract

Aim of our study was to compare the metacarpal indices in children with Marfan syndrome and constitutional tall stature and to find out whether this index discriminates the clinical impression of arachnodactyly in children with constitutional tall stature. In a posterior-anterior X-ray of the left hand in 55 children with constitutional tall stature and 54 children with Marfan syndrome the metacarpal-index was evaluated as the ratio of the maximal axial length of the second, third, fourth and fifth metacarpals to the width of the same metacarpals at their midpoints. Metacarpal indices in children with Marfan syndrome were 9.15± 0.93 (mean±SD) and in children with constitutional tall stature 8.65± 0.83. Indices in both groups were significantly different but they differ from indices found in normal individuals (less than 7.9), showing clearly arachnodactyly in both groups. We conclude that the MCI distinguish between children with Marfan syndrome and children with constitutional tall stature but there is a considerable overlap making the MCI a poor discriminator between them. Therefore all patients with tall stature or clinical signs of arachnodactyly should be carefully examined for additional signs of Marfan syndrome or other hereditary disorders of the connective tissue.