Baby Alex to leave Bambino Gesù hospital after successful bone-marrow transplant.

Baby Alex, a 20-month-old boy suffering from a rare genetic disease, is to return home to London after undergoing a successful bone-marrow transplant at Rome's Bambino Gesù hospital.

Doctors at the Vatican-run children's hospital said the child is in "good condition" - according to Italian news agency ANSA - and that the transplant treatment was concluded "in a positive way."

The innovative transplant, undertaken on 20 December, involved manipulating and infusing cells taken from the father of Baby Alex. The hospital said the cells have since "taken root perfectly, adequately repopulating the hematopoietic and immune system of the patient."

Baby Alex, who suffers from hemophagocytic lymphohistiocytosis - a rare condition affecting just 0.002 per cent of children, was transferred to Rome from London's Great Ormond Street Hospital late last year.

The boy, whose full name is Alessandro Maria Montresor, was born in London where he lives with his Italian parents.