BABAM1 plays a role in DNA repair and chromatin modification [60] and USHBP1 interacts via its C-terminus with the first PDZ domain of the Usher syndrome 1C protein, which is coded by one of several genes responsible for the Usher syndrome - a relatively rare genetic disorder that is a leading cause of deafness and gradual blindness [61]. The gene discussed is USHBP1; the disease is Down syndrome.