Oculodento-osseous dysplasia: heterogeneity or variable expression?

Oculodento-osseous dysplasia (ODOD) has been recognised in three South African patients from two kindreds of Dutch descent. Their ocular, nasal, dental and digital stigmata resembled those of previously reported cases, but their cranial hyperostosis and mandibular overgrowth were of much greater degree. In addition, the two survivors had serious neurological complications consequent upon spinal cord compression at the base of the skull and calcification of the basal ganglia. Two of the patients were the product of marriages between a pair of brothers and a pair of sisters, who were themselves clinically normal. This situation is best explained by autosomal recessive inheritance. As ODOD is usually transmitted as an autosomal dominant, and in view of the unusual severity of the manifestations in our patients, it is possible that the condition is heterogeneous and that they had a distinct autosomal recessive form of the disorder. The presence of minimal stigmata in the mother and two prior generations of our third patient could be equally well interpreted as representing great variation in phenotypic expression of a single dominant gene or manifestation in a heterozygote for a recessive gene.