A novel nonsense ATP7A pathogenic variant in a family exhibiting a variable occipital horn syndrome phenotype.

We report on a family with occipital horn syndrome (OHS) diagnosed in the proband's late fifties. A novel ATP7A pathogenic variant (c.4222A > T, p.(Lys1408*)), representing the first nonsense variant and the second late truncation causing OHS rather than classic Menkes disease, was found to segregate in the family. The predicted maintenance of transmembrane domains is consistent with a residual protein activity, which may explain the mild clinical presentation.