I was born with one foot a size smaller than my other one. What is this condition? Why was I born like that? My calf is also smaller..

See below. This is a problem that requires a face-to-face meeting with his doctor. In that meeting, his doctor will listen to him, perform a throrough examination and possibly order labs or other tests. Based on this information, he/she will be able to tell him what's wrong and what to do about it.