Prevalence of lysosomal storage disorders.

CONTEXT Lysosomal storage disorders represent a group of at least 41 genetically distinct, biochemically related, inherited diseases. Individually, these disorders are considered rare, although high prevalence values have been reported in some populations. These disorders are devastating for individuals and their families and result in considerable use of resources from health care systems; however, the magnitude of the problem is not well defined. To date, no comprehensive study has been performed on the prevalence of these disorders as a group. OBJECTIVE To determine the prevalence of lysosomal storage disorders individually and as a group in the Australian population. DESIGN Retrospective case studies. SETTING Australia, from January 1, 1980, through December 31, 1996. MAIN OUTCOME MEASURE Enzymatic diagnosis of a lysosomal storage disorder. RESULTS Twenty-seven different lysosomal storage disorders were diagnosed in 545 individuals. The prevalence ranged from 1 per 57000 live births for Gaucher disease to 1 per 4.2 million live births for sialidosis. Eighteen of 27 disorders had more than 10 diagnosed cases. As a group of disorders, the combined prevalence was 1 per 7700 live births. There was no significant increase in the rate of either clinical diagnoses or prenatal diagnoses of lysosomal storage disorders during the study period. CONCLUSIONS Individually, lysosomal storage disorders are rare genetic diseases. However, as a group, they are relatively common and represent an important health problem in Australia.