Cheyenne Mellor on Instagram: "Peter was born with a genetic mutation called TUBa1a, severe brain defects, and partial paralysis in all four limbs (quadriplegic cerebral palsy). He didn’t hold his head up until close to a year. He started sitting unassisted at 18 months. He rolled over completely for the first time at 20 months. He is now 21 months old and has started STANDING with assistance!!! #perfectpeter #peterwinston #cerebralpalsy #disabled #medicaljourney #tuba1a #braindefects #medically