National survey of prevalence and prognosis of thanatophoric dysplasia in Japan.

BACKGROUND: Thanatophoric dysplasia (TD) is a rare congenital disease of the skeletal system, with an incidence of 1.68-8.3 per 100 000 births, but statistical data on the estimated number of TD patients across Japan are not available. The aim of this study was therefore to investigate the prevalence and prognosis of TD in Japan. METHODS: A nationwide primary questionnaire survey was conducted. RESULTS: A total of 127 obstetric, 186 pediatric, and 115 orthopedic facilities provided responses. Excluding duplications, we identified 73 patients with TD. Of the 73 cases, 15 were abortions, four were stillbirths, 51 were live births, and three had unknown details. Of the 51 live newborns, 27 died ≤7 days after birth, with an early neonatal mortality rate of 56%. Of the 24 newborns who survived the early neonatal period, 16 survived for ≥1 year. All of the 24 newborns received respiratory management and survived during the early neonatal period. Of the 51 live newborns, 25 did not receive respiratory management and died ≤2 days after birth. CONCLUSIONS: The prevalence of TD in Japan is estimated to be at 1.1 (95%CI: 0.84-1.37) per 100 000 births, but the actual incidence is expected to be higher. To our knowledge, we have confirmed for the first time that newborns with TD may not always die during the early neonatal period but can survive the early neonatal period with appropriate respiratory management. Therefore, the term "thanatophoric dysplasia" does not accurately reflect the nature of the disease.

Congenital cervical instability in a patient with camptomelic dysplasia.

INTRODUCTION: Camptomelic dysplasia (CD) is a rare autosomal dominant skeletal dysplasia classically characterized by bent bones of the extremities, tracheobronchial narrowing, thoracic kyphoscoliosis, and various degrees of phenotypic sex reversal. Most patients die of complications in infancy, although long-term survivors have been reported. CASE REPORT: We report a case of CD complicated by incomplete ossification of the cervical vertebral pedicles, resulting in congenital cervical instability and kyphosis. Closed reduction was performed, and the patient was fitted with a customized cervical orthosis. FINDING: He subsequently developed a complete spinal cord injury at the kyphotic level. This underscores the grim prognosis associated with neonatal cervical spinal instability.

Dichorionic twins discordant for thanatophoric dysplasia managed with selective reduction at 20 weeks' gestation: a case report.

BACKGROUND: Thanatophoric dysplasia (TD) is a rare and lethal form of skeletal disorder. A MEDLINE search for 1965-2003 yielded only 3 reports of multiple pregnancies discordant for TD. This is the first case report of selective twin reduction for this diagnosis. CASE: A young woman was seen in consultation at 20 weeks' gestation. Ultrasound examination revealed a twin pregnancy, with ultrasound markers consistent with thanatophoric dysplasia, type II, in twin A. A thick dividing membrane and separated placentas were noted. After counseling, the patient opted for selective termination of twin A. Termination was performed by intracardiac injection of potassium chloride. The pregnancy continued uneventfully until 33 weeks, when spontaneous labor resulted in vaginal delivery of a vigorous female infant, and a mummified, macerated fetus. CONCLUSION: Selective termination for discordant lethal anomalies can be safely performed when the presence of the anomalous twin increases the risk of a poor perinatal outcome for the apparently normal cotwin.