RT Book, Section A1 Bianchi, Diana W. A1 Crombleholme, Timothy M. A1 D'Alton, Mary E. A1 Malone, Fergal D. SR Print(0) ID 1106399936 T1 Thanatophoric Dysplasia T2 Fetology: Diagnosis and Management of the Fetal Patient, 2e YR 2015 FD 2015 PB McGraw-Hill Education PP New York, NY SN 978-0-07-144201-5 LK obgyn.mhmedical.com/content.aspx?aid=1106399936 RD 2024/03/28 AB Key PointsMost common of the lethal skeletal dysplasias. Presents in the second trimester.Two subtypes exist: TD I has short curved femurs with or without a cloverleaf skull; TD II has straight, longer femurs and generally a more severe cloverleaf skull.Sporadic inheritance with extremely small recurrence risk associated with advanced paternal age (>35 years).Mutations in fibroblast growth factor receptor 3 (FGFR3) are the underlying basis for the disorder. There is a strong genotype–phenotype correlation. DNA diagnosis is highly accurate.FGFR3 is also expressed in the brain. Rare survivors are uniformly severely developmentally delayed.