The c.166G>A mutation results in an Asp-to-Asn amino acid change (p.D56N) of a conserved Asp, and the c.278G>A mutation results in an Arg-to-Gln amino acid change (p.R93Q) of a conserved Arg residue in GDNF, which has not been previously implicated in OSA. The gene discussed is GDNF; the disease is obstructive sleep apnea syndrome.