OBJECTIVE: To report a patient with thanatophoric dysplasia, an autosomal dominant and lethal form of nanism diagnosed in the prenatal period and to review the literature, discussing the main differential diagnosis and highlighting the importance of the fetal ultrasound in the identification of fetus with this dysplasia. CASE DESCRIPTION: The patient is the second son of young parents without family history of genetic diseases. The fetal ultrasound performed with 35 weeks of gestation showed polyhydramnios, prominent forehead and disproportion between skull and trunk, with thoracic hypoplasia and shortening of long bones, suggestive of thanatophoric dysplasia. At birth, the child was small and presented: hypotonia, macrocephaly, large fontanel, middle face hypoplasia, bulging eyes, nevus flammeus in the nose and eyelids, low nasal bridge, micrognathia, short neck and thorax, and an important shortening of arms, forearms, thighs and legs. Radiographic evaluation showed a great transverse diameter of the skull, thorax with short ribs and diminished vertebral bodies, shortening and deformity of the long bones of upper and lower limbs (with curved femora) and hypoplasia of the pelvis. These features confirmed the prenatal diagnosis of thanatophoric dysplasia. The patient died few days after birth due to respiratory insufficiency. COMMENTS: Fetal ultrasound is a non-invasive method capable of diagnosing several bone dysplasias, including the thanatophoric one. The intrauterine diagnosis allows the differential diagnosis of the condition as well as the genetic counseling for the family.
thanatophoric dysplasia; dwarfism; congenital abnormalities; ultrasonics; prenatal diagnosis; genetic counseling
