Is a homozygous nonsense CEP250 mutation combined with a heterozygous nonsense C2orf71 mutation associated with atypical Usher syndrome?
A homozygous nonsense CEP250 mutation, in combination with a heterozygous C2orf71 nonsense mutation, causes an atypical form of USH, characterised by early-onset SNHL and a relatively mild RP. The severe retinal involvement in the double homozygotes indicates an additive effect caused by nonsense mutations in genes encoding ciliary proteins.
Liver involvement is a common complication in 1 degrees SS. Its presence correlates with systemic disease. We consider that this complication should be routinely sought in patients with 1 degrees SS, especially when a positive anti-ENA or evidence of systemic inflammation is found.