FGF23 and LADD syndrome: 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).