- Non-syndromic progressive hearing loss DFNA38 is caused by heterozygous missense mutation in the Wolfram syndrome gene WFS1. Young, T.L., Ives, E., Lynch, E., Person, R., Snook, S., MacLaren, L., Cater, T., Griffin, A., Fernandez, B., Lee, M.K., King, M.C., Cator, T. Hum. Mol. Genet. (2001)