[4] Children may present with features such as: OHS is a milder allelic variant of Menkes disease, having a later age of onset and being associated with far less severe central neurodegeneration.

As in cases of Menkes disease, individuals with OHS manifest connective tissue abnormalities resulting from deficient activity of lysyl oxidase, a copper-requiring enzyme that normally deaminates lysine and hydroxylysine in the first step of collagen crosslink formation.

[8] The initial diagnosis of Menkes disease (MD) and its milder variants such as Occipital Horn Syndrome is based on the clinical symptoms.

Low serum copper and ceruloplasmin levels support the clinical suspicion of OHS, but biochemical confirmation in tissue culture is needed.

[14] The NIH and Cyprium Therapeutics are coordinating the joint-development of an Adeno-Associated virus gene therapy named AAV-ATP7A, for Menkes disease and its milder variants such as Occipital Horn Syndrome.

[15] In March 2017, Cyprium Therapeutics acquired the World-Wide development and commercial rights to the Menkes program at NIH/NICHD through CRADA and licensing agreements with NICHD.