Micromelic Bone Dysplasia With Cloverleaf Skull

In a survey of lethal osteochondrodysplasias in the county of Fyn (Funen), Denmark, Andersen (1989) found 2 cases of micromelic dysplasia with cloverleaf skull. One, a male, was born of a 49-year-old father and a 39-year-old mother who were not consanguineous. Micromelic bone dysplasia with cloverleaf skull has the same thoracic, pelvic, and spinal radiographic findings as thanatophoric dysplasia (187600) but does not have 'telephone receiver' femora. The micromelia is less severe than in thanatophoric dysplasia. Autosomal recessive inheritance was suggested by Elejalde and de Elejalde (1985). The age of the father in Andersen's case suggests a new dominant mutation.

It is possible that this disorder is indeed a variant of thanatophoric dysplasia and is due to mutation in the gene for fibroblast growth factor receptor-3 (FGFR3; 134934). Tavormina et al. (1995) found 3 mutations in that gene correlating with distinct subtypes of thanatophoric dysplasia.