HBB and phenylketonuria: The results showed 7 popular recessive gene mutations, including GJB2 (deafness), VPS13B (Cohen syndrome), HBB (beta-thalassemia), SLC25A13 (Citrin deficiency), GCNT2 (cataract 13), TMEM67 (Joubert syndrome), PAH (Phenylketonuria)11.