Inhabitual autosomal recessive form of dentin dysplasia type I in a large consanguineous Moroccan family.

Dentin dysplasia is a rare autosomal dominant genetic disease characterized by defect of dentin development and the causal gene is DSPP (Dentin Sialophosphoprotein gene). We report in the present study a large Moroccan family in which dentin dysplasia is clearly transmitted as an autosomal recessive trait. Four males and females family members born from healthy consanguineous parents are carriers of the typical features of the dentin dysplasia type I. Polymorphic markers that span the DSPP gene, allowed us to show that this locus is not linked to dentin dysplasia in our family. We also excluded in our family the SMOC2 gene (Sparc Related Modular Calcium Binding Protein 2) which was recently identified as a causal gene in dentin dysplasia type I with microdontia and misshapen teeth. This family represents, a new description of autosomal recessive pattern of inheritance of dentin dysplasia type I. Moreover, this form of dentin dysplasia is not allelic to the autosomal dominant dentin dysplasia and the genetic cause is to be discovered.