A perplexing case report of concomitant multiple sclerosis and myasthenia gravis.

Introduction and importance: The co-occurrence of multiple sclerosis (MS) and myasthenia gravis (MG) within the Middle East and North African Region (MENA) has been scarcely reported in current literature. This rare case report explores the pathophysiological mechanisms and potential avenues of treatment modalities. Such insights can potentially facilitate the development of more efficacious and targeted treatment modalities and perhaps pave the way for disease prevention. Case description: Twenty-nine-year-old female patient presented with diplopia of two weeks duration associated with occasional blurred vision in the left eye. On physical examination, she was discovered to have marked left eye ptosis. A visual evoked potential (VEP) test was performed, which revealed asymmetrical delay. MRI imaging revealed a few white matter hyperintense foci noted at both periventricular regions and the corpus callosum with the characteristic appearance of Dawson's fingers, and thus MS was diagnosed. An anti-acetylcholine receptor antibody test returned positive, confirming the diagnosis of concurrent MG. Clinical discussion: Proposed pathophysiological mechanisms underlying the concurrent manifestation of both diseases include, among others, the involvement of HLA haplotype and non-HLA genotypes, as well as the immunogenetic influence of specific transcription factors. Notable HLA haplotype genes include DRB1 and HLA-DQ5 genes. In contrast, non-HLA genes include the interleukin-4 receptor (IL4RA) and factor forkhead box P3 (FOXP3). Conclusion: Considering the similar immunological background of the two diseases, ideally, a single therapeutic modality could be used for management. This will hopefully simplify the patient's treatment regimen and may ultimately reduce the treatment cost and patient burden.