Identical twins with an autosomal recessive form of spondylocostal dysostosis.

A form of spondylocostal dysostosis, marked by multiple vertebral clefts, costal bifurcation, and fusion was observed in identical male twins whose parents were first cousins. The lack of previous anomalies in the family, the high degree of parental inbreeding and the absence of deformities in a 3-year-old brother indicated an autosomal recessive mode of inheritance.