The drug was originally developed as Imatinib using rational drug design after Philadelphia chromosome mutation was discovered.

FORBES: India Court Ruling Against Novartis Is Dark Omen For Big Pharma

The rarer oculocutaneous albinism type 3 is caused by a gene mutation on chromosome 9 and has been primarily identified in black South Africans.

CNN: Albinism

Oculocutaneous albinism type 4, caused by a gene mutation on chromosome 5, is an uncommon form of the disorder generally presenting signs and symptoms similar to those of type 2.

CNN: Albinism

Oculocutaneous albinism type 1 is caused by a mutation in a gene on chromosome 11.

CNN: Albinism

Oculocutaneous albinism type 2 is caused by a mutation in a gene on chromosome 15.

CNN: Albinism

That meant the mutation was almost certainly on a gene on the X chromosome.

FORBES: A Tragic Case And A Genomic Hope