Survival to adulthood and dominant inheritance of platyspondylic skeletal dysplasia, Torrance-Luton type

Abstract

We present a second family with survival to adulthood and dominant transmission of the Torrance-Luton type of platyspondylic chondrodysplasia, and demonstrate the radiographs at different ages together with radiographs and further data of the first family which was published in the Journal of Pediatrics (J Pediatr 136:411-413). Two families are described with survival to adulthood and dominant transmission of the Torrance-Luton type of platyspondylic chondrodysplasia. Although lethality is increased in patients with this disorder, mild expressions of the genetic defect are compatible with survival into adulthood. The heterogeneous group of platyspondylic lethal skeletal dysplasias (PLSD) originally included thanatophoric dysplasias (TD1/2: MIM 187600, 187100) as the most common forms of this condition, as well as TD variants San Diego type (PLSD-SD: MIM 270230) and Torrance-Luton type (PLSD-TL: MIM 151210). Fibroblast growth factor receptor 3 ( FGFR3) gene mutations have been detected in TD1/2 and PLSD-SD. Molecular studies in one of our two families with the Torrance-Luton type did not disclose mutations in the FGFR3 coding region, suggesting that this type of platyspondylic chondrodysplasia is not a thanatophoric dysplasia variant. In contrast to TD1/2 and PLD-SD, the Torrance-Luton type platyspondylic dysplasia is compatible with survival to adulthood.