Several protein-coding genes are known to be mutated in KS and/or in normosmic CHH (nCHH) patients, including KAL1, FGFR1, FGF8, PROK-2, PROKR-2, Kiss1R/GPR54, NELF, CHD7, GnRH-R, GnRH-R, HS6ST1, TAC3, TACR3, SOX10, SEMA3a and 5 members of the “FGF8-synexpressome” (Bonomi et al., 2012; Cadman et al., 2007; Cariboni and Maggi, 2006; Dode and Hardelin, 2009; Hardelin and Dode, 2008; Hu et al., 2003; Miraoui et al., 2013; Semple and Topaloglu, 2010; Topaloglu and Kotan, 2010). Here, FGF8 is linked to cartilage-hair hypoplasia.