TUBB4B and Leber congenital amaurosis: Indeed, a single individual has been identified carrying a de novo p.Q11R variant in TUBB4B without clear PCD and exhibiting instead sensorineural hearing loss but not LCA, renal Fanconi Syndrome and hypophasphatemic rickets (51).The Q11 residue is close to the tubulin catalytic GTPase site and is proposed to lead to hyperstabilized microtubules.