Further heterogeneity of the oral-facial-digital syndromes.

Two patients with polysyndactyly of the halluces and typical features of oral-facial-digital syndrome, type I (OFS I), are described. Previously, bilateral hallucal polysyndactyly was considered to be a distinctive feature of OFD II, Mohr syndrome. The original classification of OFD II was based on clinical similarities between the affected members of the Mohr-Claussen kindred and the two siblings described by Rimoin and Edgerton. Review of these cases deomnstrates important clinical differences, so that justification for the original classification of OFD II is questioned. Retrospectively, a small number of individuals have been considered to have had OFD II, but on review these cases appear to represent a clinically heterogeneous group of disorders.