A novel form of ischio-vertebral syndrome.

We report a boy with ischial hypoplasia, vertebral malsegmentation and multiple other skeletal anomalies which do not fit well with any previously-described disorder. The proband's brother and mother were also slightly affected. We review the pertinent literature, discuss the differential diagnosis and suggest that this may be a previously unreported autosomal dominant disorder, with variable penetrance.We believe that the clinical and radiological features of various syndromes with ischial aplasia/hypoplasia and vertebral malsegmentation are not sufficiently different to justify the current separate categories of "ischio-vertebral dysplasia" and "ischio-spinal dysostosis". We suggest that the term "ischio-vertebral syndrome" should be used until identification of genes affecting ischial and axial morphogenesis is completed.