Overlapping phenotypes in OFD type II and OFD type VI

Abstract

Mohr syndrome [orofaciodigital (OFD) syndrome type II] is an autosomal recessive condition that presents with short stature, broad or a bifid nasal tip, orofacial clefts, hypertrophied oral frenulae, tongue nodules or lobulated tongue, and digital anomalies. The features of OFD type II overlap with those of OFD type VI, Joubert syndrome, and short rib polydactyly (Majewski syndrome). Patients with OFD seen in our genetics in the last 4 years were reviewed. Of the five patients with OFD seen, two had Y-shaped metacarpals and other abnormalities consistent with the phenotypic spectrum of Mohr syndrome. They also had the additional radiological features of hypoplastic middle phalanges of index fingers and a hypertrophied or enlarged metatarsal with multiple phalanges arising from it. We hypothesize that type II and type VI OFD syndromes represent a continuum of the same phenotypic spectrum with severe central nervous system abnormalities at the more severe end of the spectrum.