Wolfram syndrome, a rare form of monogenic diabetes and neurodegeneration, currently has no cure or treatment to slow the progression. Currently we have no way of predicting progression to blindness, or how different genetic mutations may affect this progression. This paper shows that affected people who retain partial Wolfram protein expression, present with milder visual impairment compared with people who lose all protein expression. This suggests a protective effect of partial WFS1 protein expression on the severity and perhaps progression of vision impairment, and that therapies to increase residual WFS1 protein expression may be beneficial. (By Professor Timothy G Barrett, https://jmg.bmj.com/content/early/2021/05/18/jmedgenet-2020-107257 )