For example, loss of function of FGF3 causes deafness, heterozygous loss of function of FGF10 results in lacrimo-auriculo-dento-digital syndrome (LADD syndrome), FGF10 haploinsufficiency is also associated with chronic obstructive pulmonary disease and FGF23 gain of function leads to autosomal dominant hypophosphataemic rickets (26–29). The gene discussed is FGF3; the disease is LADD syndrome.