Ischio-spinal dysostosis: a previously unrecognised combination of malformations

Background. Ischial hypoplasia is an extremely rare malformation, both as an isolated anomaly and as a syndromic constituent. Objective. To elucidate the clinical and radiological characteristics in five patients with the combination of ischial hypoplasia and spinal malformations. Materials and methods. The clinical records and radiographs of two females and three males, ranging in age from 3 months to 38 years, were evaluated. Results. Ossification defects of the ischial rami were symmetrical and total in four patients, whereas the right ischial ramus was partly ossified in the other patient. All patients possessed multiple segmental defects of the spine, with rib anomalies of varying severity. One patient characteristically showed multiple rib gaps, resulting in respiratory distress. Severe anomalies of the cervical spine were evident in two patients. Four patients exhibited lumbosacral hypoplasia, which ultimately led to cauda equina syndrome in three older patients. One patient had mild facial dysmorphism and another had a diversity of anomalies, including ichthyosiform skin changes. Four patients were sporadic cases, whereas the other patient was born to consanguineous parents. Conclusions. The combination of anomalies in these patients constitutes a recognisable pattern of malformations but may represent a heterogeneous group of disorders.