Report a novel case of myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) presenting as relapsing bilateral optic neuritis in a pediatric patient with Wiskott-Aldrich syndrome (WAS).

WAS is a rare X-linked primary immunodeficiency caused by mutations in the WAS gene that leads to increased susceptibility to infections, thrombocytopenia, eczema, malignancies, and autoimmunity. Known CNS autoimmune manifestations include cerebral vasculitis, but optic neuritis, CNS demyelination, and MOGAD have not been previously reported.

Chart review

A 5-year-old boy with a history of chronic immune thrombocytopenia, hypogammaglobulinemia, anemia, and focal epilepsy developed binocular vision loss. MRI of the brain demonstrated enlargement of bilateral optic nerves with marked enhancement of the nerve sheaths consistent with optic neuritis, as well as multiple small enhancing supratentorial lesions. He was treated with pulse methylprednisolone followed by oral steroid taper, and he returned to baseline with no reported residual visual deficits. Five months later, he experienced a relapse of bilateral vision loss, and repeat MRI re-demonstrated bilateral optic neuritis as well as resolution of prior brain lesions. He was treated with repeat course of steroids and experienced moderate improvement in his vision. Rituximab was then initiated to prevent further relapses of optic neuritis while treating his chronic suspected immune-mediated thrombocytopenia. Myelin oligodendrocyte glycoprotein antibody (MOG-IgG) via serum fluorescence-activated cell sorting assay was positive (titer 1:100), confirming a diagnosis of MOGAD. At age six, molecular panel testing for genes associated with primary immunodeficiency identified a missense WAS gene variant. He was subsequently found to have decreased WAS protein expression consistent with a diagnosis of WAS.

We describe a case of pediatric MOGAD presenting with multiphasic bilateral optic neuritis in a patient with WAS. This case expands the reported spectrum of CNS autoimmunity associated with WAS and may help to inform indications for therapeutic options such as bone marrow transplant.