We found a 2.2 Mbp inversion between TBC1D3 clusters in one Amerindian haplotype, consistent with ongoing nonallelic homologous recombination between inverted TBC1D3 gene clusters, which may provide a substrate for the recurrent 17q12 microdeletion syndrome associated with renal cyst and diabetes syndrome (RCAD) (Mefford et al. 2007). The gene discussed is TBC1D3; the disease is renal cysts and diabetes syndrome.