[Thanatophoric dysplasia: three patients hospitalized in PAIP in 1994-2000].

BACKGROUND

Thanatophoric dwarfism is a lethal bone dysplasia causing severe disturbance in body proportions, shortening and deformation of the long bones and maldevelopment of the chest leading to severe respiratory failure and early death. The disease is caused usually by de novo mutation in the gene of fibroblast growth factor receptor 3 (FGFR3). Inheritance is autosomal dominant. The most common mutation C742T leads to substitution of arginine by cysteine in 248 position of polypeptide (R248C).

OBJECTIVE

Presentation of clinical picture, radiological findings and molecular diagnostics in three patients with TD hospitalized in PAIP in 1994-2000.

METHODS

Three patients with TD were hospitalized in PAIP between 1994 and 2000. They were admitted in the 1st, 2nd, 19th day of life. Two patients were referred with diagnosis of achondroplasia. One newborn was born after uncomplicated pregnancy with cesarean section due to large head circumference found on prenatal USG. Two other newborns were born preterm (34 week of gestation), vaginally. One pregnancy was complicated by polyhydramnios. All patients required oxygen therapy, two were artificially ventilated (21 and 16 days). Three newborns died due to respiratory failure, average length of life--29 days.

RESULTS

The diagnosis was established based on clinical presentation (abnormal proportions, shortening and deformation of the extremities, maldevelopment of the chest, large cranium) and radiological presentation (typical vertebral bodies, long bones shaped as telephone receiver). In two cases molecular analysis was performed, which excluded achondroplasia, in one of those patients molecular studies directly confirmed presence of the most common mutation leading to TD (R248C).