A comparison of multiple sclerosis disease characteristics across three genetically diverse Asian racial groups in Singapore.

Studies in Western populations have shown that Black and Hispanic patients have an earlier age of Multiple Sclerosis (MS) onset and a more severe disease course characterised by faster disability accrual compared to Whites. It is yet unclear whether MS disease characteristics and clinical course differ amongst Asian racial groups. Singapore is uniquely poised to investigate this as its multi-racial population comprises three genetically diverse Asian racial groups-Chinese, Malay and South Asian. Herein, we sought to elucidate differences in the clinical phenotypes, disease-modifying therapy (DMT) usage, and disease course amongst these three Asian racial groups by performinga retrospective observational study on MS patients seen at the National Neuroscience Institute, Singapore. Data on demographics, disease characteristics, ancillary investigations, and DMT usage were collected. One hundred and eighty-eight patients were included (90 Chinese, 32 Malay, and 66 South Asian). Our findings showed that MS prevalence was the highest in South Asians followed by Malays and Chinese, while demographics, healthcare access, and longer-term disease course were identical across the racial groups. However, several differences and trends were elucidated: (1) South Asian patients had milder sentinel attacks (p = 0.006), (2) a higher proportion of Malay patients had enhancing lesions on their initial MRI (p = 0.057) and the lesion topography differed across the races (p = 0.034), and (3) more Malay patients switched out of their initial DMT (p = 0.051). In conclusion, MS disease characteristics were largely similar across these three Asian racial groups, and while there were some clinical and radiological differences at presentation, these did not influence longer-term outcomes.