Paracentral acute middle maculopathy as a major clinical manifestation of adenosine deaminase-2 deficiency

Adenosine deaminase-2 (ADA2) deficiency is a rare autosomal recessive autoinflammatory syndrome, typically presenting in young patients with a broad spectrum of phenotypes. These phenotypes usually include primary immune deficiencies, livedo reticularis, and hematological abnormalities. Visual loss associated with ADA2 deficiency is uncommon and, when it does occur, is often linked to major vascular involvement, such as occlusion of the ophthalmic arteries. Paracentral acute middle maculopathy (PAMM) is an optical coherence tomography (OCT) finding characterized by ischemia at the inner retinal capillary complex rather than the major retinal vessels. It has been previous associated with a variety of systemic diseases, retinal vascular diseases, and drugs side-effects, but never with ADA2 deficiency until this moment.

A 31-year-old woman with a presumptive diagnosis of common variable immunodeficiency and livedo reticularis presented with sudden onset severe visual loss in the left eye due to PAMM followed a few weeks later by a lacunar stroke. An extensive laboratory investigation including genetic testing led to the diagnosis of ADA2 deficiency, a rare recessively inherited autoinflammatory syndrome. Treatment regimen was switched to anti-TNF-α inhibitors, leading to disease remission with no further vascular events over a two-year follow-up period.

This case serves to emphasize the importance of considering ADA2 deficiency in patients with PAMM, particularly when it occurs in young patients with a history of strokes and/or immunological abnormalities.