Prevalence of lysosomal storage disease (LSD) in Malaysia

Lysosomal storage disorders (LSD) are storage disorders involving the malfunction of degradation enzymes in the lysosome. This study aimed to calculate the birth prevalence and carrier frequency of LSDs in the Malaysian population, to compare our results with previously reported epidemiologic data from other populations, and to describe the mutation spectrum in Malaysia. Between 2008 and 2017, 2.1% (92/4338) of suspected patients were diagnosed with LSD. The prevalence of LSD and carrier frequency in Malaysia were 0.43 per 100,000 live births and 1 in 241, respectively. The combined prevalence of mucopolysaccharidoses (MPS) and its carrier frequency were 0.34 per 100,000 live births and 1 in 271, respectively. Among this MPS group, MPS II presented the highest calculated birth prevalence of 0.45 per 100,000 male live births with a carrier frequency of 1 in 236. Within the group of sphingolipidoses, the combined prevalence was 0.13 per 100,000 live births with a carrier frequency of 1 in 439. Fabry disease was the most common disorder with a calculated prevalence of 0.52 per 100,000 male live births and a carrier frequency of 1 in 220 followed by metachromatic leukodystrophy (MLD) (0.2 per 100,000 live birth and carrier frequency 1 in 352). MLD is more common among people of Iban ethnicity with a prevalence of 14.33 per 100,00 live births and a carrier frequency of 1 in 42. Pompe and mucolipidosis type II are the less common subtypes of LSD with a prevalence of 0.06 per 100,000 live births and a carrier frequency of 1 in 651 and 0.04 per 100,000 live births with carrier frequency of 1 in 747, respectively. Overall, although the prevalence of LSD in Malaysia may be underestimated, the prevalence of MPS is consistent with reports done in other Asian countries.