IL17RD (Interleukin 17 receptor D; chr 3p14.3) has been identified as a KS causative gene due to large-scale protein–protein interaction analysis, based on the idea that in addition to FGFR1/ANOS1/HS6ST1, other FGF signaling-related proteins may be implicated in CHH pathogenesis coupled with severe hearing loss [214]. This evidence concerns the gene IL17RD and cartilage-hair hypoplasia.