P33.09: 3D ultrasound, MRI and molecular diagnosis of thanatophoric dysplasia type I

Abstract

Skeletal dysplasias are a heterogeneous group of bone growth disorders with different fetal outcomes. Prenatal sonographic examination is an excellent method for discovering fetal skeletal dysplasias. However, it is not always possible to differentiate TD from others skeletal dysplasias by ultrasonography alone and molecular genetic analysis of the fibroblast growth factor receptor 3 (fgfr3) gene is useful for prenatal diagnosis of TD. Therefore definitive diagnosis should always be accomplished by a comprehensive postnatal evaluation, including clinical, radiological, pathological, biochemical and molecular genetic examination. Thanatophoric dysplasia (TD) is the most common form of platyspondylic lethal skeletal dysplasias and TD 1 is characterized by short limbs, a narrow thoracic cage, straight femora, with or without a cloverleaf skull. In this report, one fetus with TD 1 was diagnosed by 3D ultrasound and MRI in the second trimester, and molecular analyses of the fgfr3 gene confirmed the postnatal diagnosis.