Neurodevelopmental outcomes in two cases of artemis deficiency

Background: Severe Combined Immunodeficiency (SCID) is a category of inborn errors of immunity where there is impaired T and B cell development and/or function. Artemis SCID (Art-SCID) is characterized by dysfunctional Artemis protein, which is crucial for V(D)J recombination in T and B cell maturation. Art-SCID is fatal without management, and current definitive treatment involves hematopoietic stem cell transplantation (HSCT) or gene therapy. As the prognosis and survival of SCID patients improves, current research has begun unveiling longterm complications and morbidities. Previous literature has reported neurodevelopmental abnormalities in SCID patients, such as developmental delay and Autism Spectrum Disorder (ASD). However, it remains unknown whether these neurodevelopmental differences are linked to the SCID mutation, an adverse outcome of treatment and hospitalization, or comorbid social isolation and psychosocial challenges. Aims: In this case series, we discuss two cases of Art-SCID which presented with neurodevelopmental deficits following successful HSCT. Results: In both cases, SCID was detected on Newborn Screening (NBS), and Art-SCID was confirmed with genetic testing. Both patients were successfully treated with HSCT at 80 days of life, and followed up clinically well, with robust cell counts. Both patients later presented in toddlerhood with developmental, speech and language delay, however only one patient met diagnostic criteria for ASD. Conclusion: The definitive relationship between SCID, HSCT, and neurodevelopmental outcomes remain unclear, and warrants further study to allow for early intervention. We are currently working with colleagues across the country to further investigate and define this complex relationship. Statement of Novelty: We are investigating the complex relationship between SCID, HSCT, and potential neurodevelopmental outcomes. We present two cases of patients with Artemis SCID who were successfully treated with HSCT, and later presented in toddlerhood with developmental, speech, and language delay.