Mitochondrial Disease in Children: The Nephrologist’s Perspective

Mitochondrial diseases (MD) are a heterogeneous group of clinical syndromes characterized by the involvement of different organ systems. They constitute the most prevalent hereditary metabolic disease group.To review the importance of the kidney in MD from the nephrologist's perspective within the setting of a pediatric tertiary reference center.Retrospective study of children (18 years) with MD followed between 2000 and 2016 at a tertiary Spanish center.52 patients were included. The mean age at the time of the study was 10 years (SD ± 5.1). The mean follow-up time was 6.1 years (SD ± 4.7). The median age at diagnosis was 2.5 years (0.3-13.5).The median number of affected systems was two (range 1-6). The nervous system was the most affected system, with 51 patients (~98%) presenting with neurological involvement. 20 patients (~40%) presented with endocrinological manifestations, 18 (~35%) with vision problems, 16 (~30%) with gastrointestinal symptoms, 5 (~10%) patients developed hearing impairment, and 6 (~10%) cardiac disease.We detected renal involvement in 13 patients (25%). Eight patients had tubular disease, most frequently hypercalciuria with hypouricemia and five patients had glomerular involvement, with proteinuria and/or decreased glomerular filtration rate as the most frequent symptoms. Only 21 patients (~40%) had been seen by a pediatric nephrologist.Renal disease was a common occurrence in patients with mitochondrial disease, present in our study in 25% of patients. A regular screening of renal function parameters and the involvement of a nephrologist as part of the multidisciplinary approach to mitochondrial disease appears warranted.