Relative incidence of inherited white matter disorders in childhood to acquired pediatric demyelinating disorders

Abstract

Epidemiologic frequencies of pediatric white matter disorders as a class have not been well defined. This is particularly true of genetic disorders of the white matter of the brain. In this study, ICD-9 codes were used to estimate relative incidence rates and descriptive statistics of leukodystrophies, other genetic leukoencephalopathies and acquired demyelinating disease among children residing in the Washington, D.C. metropolitan area. Children being treated at US children's hospitals between January 1, 2004, and December 31, 2009, for acquired demyelinating disease or genetic white matter disorders were captured using the Pediatric Health Information System and the Physician Practice Management system and validated with local electronic medical records. Comparisons were made between genetic white matter disorders and acquired demyelinating disorders, to determine differences in incidence, age, gender, ethnicity, and mortality. Genetic causes of white matter disease identified with ICD-9 codes had an estimated incidence of 1.2/100,000 children in the Washington, DC area. What was of interest was nearly 5 out of 10 cases of pediatric white matter disease of any etiology were attributable to genetic causes. When only progressive white matter diseases were considered, 7 out of 10 cases were attributable to genetic causes, and only 3 out of 10 to progressive acquired demyelinating disease such as multiple sclerosis. These findings signify the important contribution of heritable white matter disorders to pediatric neurologic disease in the Washington, DC, metro area as well as throughout the United States. Continued research of these understudied disorders should compare disease incidence and determinants to validate these findings in different populations.