We performed whole-exome sequencing (WES) for eight patients with Kallmann syndrome or normosmic CHH who carried no mutations in 14 major causative genes for CHH (ANOS1, CHD7, FGF8, FGFR1, GNRH1, GNRHR, KISS1, KISS1R, PROK2, PROKR2, SOX10, TAC3, TACR3, and WDR11). Here, PROK2 is linked to cartilage-hair hypoplasia.