The HbH-CS patients develop a severe form of the disease with hepatosplenomegaly, growth retardation, or transfusion-dependent hemoglobinopathy due to low α-globin chain synthesis and the presence of abnormal HbCS, whereas individuals with the classical HbH disease are usually less anemic and asymptomatic in steady state [5]. The gene discussed is HBA2; the disease is Cowden syndrome 1.