For example, Chinese Gγ(Aγδβ)0 thalassemia/SEA-HPFH combined with point mutations in the HBB gene is the most common and rare point mutations in the HBB gene are a main cause for prenatal diagnosis in at-risk couples with a history of having children with severe β thalassemia syndrome (Xu L. L. et al., 2020). Here, HBB is linked to thalassemia.