Spondyloepimetaphyseal dysplasia with joint laxity (Beighton type): A unique South African disorder

Spondyloepimetaphyseal dysplasia with joint laxity (SEMD-JL) is an autosomal recessive skeletal dysplasia in which stunted stature, articular hypermobility and spinal malalignment are the major manifestations. Structural cardiac abnormalities are sometimes present. Approximately 30 affected children have been recognised previously in the Afrikaans-speaking community in South Africa, and in several, mutations in the B3GALT6 gene have been incriminated. In this article, case details of three additional affected children in two families are documented, and four additional families are mentioned. The Pierre-Robin sequence and unilateral renal agenesis are previously unreported concomitants. The mutational status where known is recorded.