Leukodystrophies and genetic leukoencephalopathies in childhood: a national epidemiological study

Aim To report on the epidemiology of the brain white matter disorders of children identified via a national prospective study. Method Since 1997 a study of UK children with progressive intellectual and neurological deterioration (PIND) has used the British Paediatric Surveillance Unit system to identify children with progressive neurodegenerative disease. This paper reports on children in the study with brain white matter disorders. Results Between May 1997 and November 2014 the PIND study identified 349 children with diagnosed leukodystrophies, giving an estimated UK lifetime risk of 31/million live births. There were 18 specific diseases in the group and relatively large numbers of affected children came from consanguineous Pakistani families. In addition there were 454 children with genetic leukoencephalopathies – in this group there were 38 diseases. 5.8% of children with scan evidence of brain white matter disorders did not receive a specific diagnosis. Interpretation These unique prospectively‐obtained national data avoid the selection bias inherent in reports from single centres. White matter disorders of the central nervous system comprise more than half of UK paediatric neurodegenerative diseases meeting the PIND criteria. This paper reports the lifetime risk/million live births for the commonest leukodystrophies, providing a basis for comparison with future studies. What this paper adds This prospective national epidemiological study found 18 different leukodystrophies and 38 genetic leukoencephalopathies. Leukodystrophies and genetic leukoencephalopathies are major causes of paediatric neurodegeneration. The data provide a sound basis for comparison with future studies. This article is commented on by Bonkowsky on pages 650–651 of this issue. Video Podcast: https://youtu.be/RUCk65Z_98M