In 2003, FGFR1 was identified as the first gene underlying the autosomal dominant form of KS (Dode et al, 2003), and subsequently, loss‐of‐function FGFR1 mutations were identified in CHH patients with normal olfaction (Pitteloud et al, 2006). This evidence concerns the gene FGFR1 and cartilage-hair hypoplasia.