AbstractThanatophoric dysplasia (TD) is a type of lethal skeletal dysplasia having very rare description about its clinical profile in medical literature. Here we discuss the anatomical features, abnormalities and clinical profile of Thanatophoric dysplasia in the present study. A search of PubMed, Web of Science, and EMBASE and google search was made to identify previous citations in the English literature reporting sonographic findings in fetuses with Thanatophoric dysplasia. We used key words related to Thanatophoric dysplasia and prenatal ultrasound, including ‘thanatophoric dysplasia’, ‘ultrasound’, ‘prenatal’, ‘sonography’, ‘skeletal dysplasia’, ‘limb shortening’, ‘macrocephaly’, ‘telephone receiver femur’ and ‘cloverleaf skull’ etc. Studies where the diagnosis of thanatophoric dysplasia was confirmed by radiological findings or molecular diagnosis were included in our study. We have found 34 cases of thanatophoric dysplasia from 1971 to 2016. Out of these 34 cases 17 were type 1 and two cases were type 2. Out of 34 cases 5 cases are diagnosed before 20 weeks, 5 cases were diagnosed between 2026 weeks and 22 cases were diagnosed after 26 weeks. The most common anomalies found are narrow thorax (100%), Platyspondily (41.1%), Hypoplastic pelvic bones (50%), Telephone receiver femur (55.8%), Short ribs (38.2%), Clover leaf skull (26.4%), Frontal bossing (35.2%), brachydactily (26.4%) and Depressed Nasal Bridge (26.4%). Out of nine cases where the the difference between gestational age measured by biparietaldimeter (BPD) and femur length (FL) were reported only one case had been reported to be diagnosed before 20weeks where the difference is 5 weeks. Three cases were diagnosed between 20 and 26 weeks where the difference is 78 week, 7+2 week and 8+6 week respectively. In the rest five cases the difference of gestational age ranges from 1016 weeks to 24 weeks. Any discordance between femur length measurement and abdominal circumference or head circumference in first or early second trimester ultrasound should be suspected for this dysplasia. Counseling of the affected A parent about the low recurrence rate is also an important part of management.
Keywords: Thanatophoric Dysplasia; Telephone Receiver Femur; Clover Leaf Skull; Limb Shortening.