The six-month-old boy, named Gammy, also has a congenital heart condition and needs urgent medical treatment.
Pattaramon Chanbua was left to care for him after his Australian parents only wanted his healthy twin sister.
She was paid $15,000 (£9,000) to be a surrogate for the couple, whose identities remain unknown.
Mrs Chanbua was told of the child's condition four months after becoming pregnant and the couple asked her to have an abortion but she refused, saying it was against her Buddhist beliefs. (...)