The importance of early prenatal diagnosis of thanatophoric dysplasia with respect to obstetric management

A case of thanatophoric dysplasia type I with an R248C mutation in the FGFR3 gene

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.

Prenatal diagnosis of skeletal dysplasia identified postnatally as hypochondroplasia

A short-limb skeletal dysplasia was diagnosed prenatally at 35 weeks of gestation. After birth the infant was found to have hypochondroplasia. The parents are of average stature, and the child's disorder presumably occurred as a fresh mutation. This appears to be the first reported case of hypochondroplasia diagnosed prenatally as a "non-specific skeletal dysplasia" in the absence of a family history. Evaluation after birth showed that the infant, whose parents are of normal stature, has hypochondroplasia.