Genic CNV can be responsible for 14–60% of disease alleles in selected recent studies of novel disease genes (BPTF [59], NONO [60], PSMD12 [61], TANGO2 [62], TRIP12 [65]) and 7–26% of families of different disease cohorts (Bardet Biedl ciliopathies [84], primary immune deficiency disorders [85], brain malformations [36], an Arabic DD cohort [86], unsolved clinical exomes [87]). The gene discussed is TANGO2; the disease is dentin dysplasia.