<prompt> Please answer with one of the option in the bracket. Write reasoning in between . Write answer in between .Q:A 4-year-old boy is brought to the pediatrician by his mother for a routine medical examination. His medical history is relevant for delayed gross motor milestones. The mother is concerned about a growth delay because both of his brothers were twice his size at this age. Physical examination reveals a well-groomed and healthy boy with a prominent forehead and short stature, in addition to shortened upper and lower extremities with a normal vertebral column. The patients vitals reveal: temperature 36.5C 97.6F; pulse 60min; and respiratory rate 17min and a normal intelligence quotient IQ. A mutation in which of the following genes is the most likely cause underlying the patients condition?? A: Alpha-1 type I collagen, B: Fibrillin-1, C: Fibroblast growth factor receptor 3, D: Insulin-like growth factor 1 receptor, E: Runt-related transcription factor 2,  <response>: This is a clinical vignette describing a 4-year-old boy with short stature, shortened limbs, and prominent forehead. The description of delayed gross motor milestones, short stature, shortened limbs with normal vertebral column, and normal intelligence points to a skeletal dysplasia. Of the choices given, a mutation in the fibroblast growth factor receptor 3 FGFR3 gene is most consistent with the clinical findings described, which are classic for achondroplasia, the most common form of dwarfism. Achondroplasia is caused by a gain-of-function mutation in FGFR3 which leads to impaired endochondral ossification and linear bone growth. The other gene mutations listed would not lead to the constellation of clinical findings described.C: Fibroblast growth factor receptor 3 