This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Skeletal System, Subject name: Radiology
[{'content': 'Absent/hypoplastic radius is a feature of? \nSelect and explain. \nA. Holt-Oram syndrome, B. Spondyloepiphyseal dysplasia, C. Chondrodysplasia punctata, D. CCD', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Ans ARadial hypoplasia more commonly a sporadic mutation rather than an inherited condition. In case of an inherited condition, several syndromes are known such as the Holt- Oram syndrome, VATER syndrome, Fanconi anemia and TAR syndrome. Other possible causes are an injury to the apical ectodermal ridge during upper limb development, intrauterine compression & maternal drug use (thalidomide).', 'role': 'assistant'}]