_:vb50947400 . _:vb50947400 . _:vb50947400 "url:http://en.wikipedia.org/wiki/Alpha_Thalassemia"^^ . _:vb50947400 . _:vb50947400 . _:vb50947400 "Alpha thalassemia is a thalassemia involving the genes HBA1and HBA2 hemoglobin genes."^^ . _:vb50947400 .