Etiologic Spectrum of Pediatric-Onset Leukodystrophies and Genetic Leukoencephalopathies: The Five-Year Experience of a Tertiary Care Center in Southern India.

Background: White matter (WM) disorders with a genetic etiology are classified as leukodystrophies (LDs) and genetic leukoencephalopathies (GLEs). There are very few studies pertaining to the etiologic spectrum of these disorders in the Asian Indian population.

Methods: This study was conducted over a period of five years from January 2016 to December 2020, in the medical genetics department of a tertiary care hospital in southern India. A total of 107 patients up to age 18 years, with a diagnosis of a genetic WM disorder confirmed by molecular genetic testing and/or metabolic testing, were included in the study and categorized into LD or GLE group as per the classification suggested by the Global Leukodystrophy Initiative consortium in 2015.

Results: Forty-one patients were diagnosed to have LDs, and 66 patients had GLEs. The two most common LDs were metachromatic LD (16 patients) and X-linked adrenoleukodystrophy (seven patients). In the GLE group, lysosomal storage disorders were the most common (40 patients) followed by mitochondrial disorders (nine patients), with other metabolic disorders and miscellaneous conditions making up the rest. The clinical presentations, neuroimaging findings, and mutation spectrum of the patients in our cohort are discussed.

Conclusions: This is one of the largest cohorts of genetic WM disorders reported till date from the Asian Indian population. The etiologies and clinical presentations identified in our study cohort are similar to those found in other Indian studies as well as in studies based on other populations from different parts of the world.