What is the likely outcome of Thanatotrophic dysplasia?

Thanatotrophic dysplasia is a severe skeletal dysplasia characterized by the presence of significant skeletal malformations, particularly affecting the growth of long bones and resulting in a characteristic "telephone receiver" shape of the femur. Infants diagnosed with thanatotrophic dysplasia typically have extremely short stature and an enlarged head, along with other features such as bell-shaped thorax and short ribs.

The term "thanatotrophic" itself refers to the condition being lethal, as many affected infants do not survive past the neonatal period. This is due to the respiratory complications that arise from the underdeveloped thoracic cavity and the associated anatomical anomalies. Therefore, the correct answer reflects the high mortality rate associated with this specific dysplasia, making it the most commonly lethal form of skeletal dysplasia.

The other options—suggesting good survival, mild abnormalities, or late-onset disorders—misrepresent the severity and critical nature of thanatotrophic dysplasia, which is characterized by its early lethality and profound skeletal impacts.