Maple Syrup Urine disease is caused from the body unable to produce Valine, along with leucine and isoleucine (essential amino acids, which the body can't produce on it's own). Contact your peditrician regarding this matter. If left untreated, it leds to brain damaage also, infants have been known to die from this if left untreated!
There's a disorder called Maple Syrup Urine Disease that might be at fault. This metabolic disorder gets its name from the burned sugar smell it causes in the urine. See http://www.msud-support.org/ for information.
I'd advise that you alert the parents to discuss this possibility with their pediatrician.
Hope this helps.