Zou Xin-Yi et al. systematically reviewed the patients with BBS reported from China and found that those with variants in BBS2 had higher hearing impairment, while those with variants in BBS10 had lower renal abnormality penetrance [41]; Veronika et al. revealed that differences in the penetrance of kidney anomalies among patients make biological sense as the causative genes linked to a high frequency of kidney anomalies, which include BBS2, BBS7, and BBS9, encode structurally similar proteins that form the core of the BBSome [75]. This evidence concerns the gene BBS9 and Hearing impairment.