Thanatophoric dysplasia (TD) is a short-limb neonatal dwarfism syndrome that is usually lethal in the perinatal period. It is characterized by shortening of the limbs, severely small thorax, large head with a prominent forehead, macrocephaly, curved femur, and flattened vertebral bodies. These malformations result from the mutation in fibroblast growth factor receptor 3 (FGFR-3) gene which is located on the short arm of chromosome 4. A definite diagnosis should be established by molecular genetic analysis to find out the abnormal mutations in the $FGFR3$ gene. We confirmed by detection of a R248C mutation in the $FGFR3$ gene in DNA analysis.