The introduction in anosmin-1 of the missense mutation F517L found in patients suffering from KS annulled the chemotactic activity; however, the mutant form carrying the disease-causing mutation E514K also found in KS patients, behaved as the wild-type protein.
A missense mutation of KAL1, c.1828G>A, led to pVal610Ile substitution in two brothers with KS; their mother is heterozygous for this missense mutation encoded by single-nucleotide polymorphism rs2229013.