Symptoms of<unk><unk>  include bulbar palsy, hearing loss, facial weakness, and difficulty breathing. The<unk>  is caused by mutations in the SLC52A2 gene and the SLC52A1 (GPR172B) genes which code for hRFT3 and hRFT1, human riboflavin transporters. Only muscle biopsy and examination of the transporter genes is considered to provide a definitive diagnosis. However, because the<unk>  is so often fatal without treatment, and because the treatment is so inexpensive and with little risk, it is recommended that if the<unk>  is suspected that riboflavin therapy be started immediately while testing is in progress.
Fazio–Londe disease
XMEN disease
Hajdu–Cheney syndrome
Crigler–Najjar syndrome
Baggio–Yoshinari syndrome
Klüver–Bucy syndrome
DeSanto-Shinawi syndrome
Treacher Collins syndrome