Mitochondrial encephalopathy with lactic acidosis and stroke-like episodes syndrome with hypothyroidism and focal segmental glomerulosclerosis in a paediatric patient

Abstract

Herein, we report on a paediatric patient with mitochondrial encephalopathy, lactic acidosis and stroke-like episodes (MELAS) who was hospitalized for acute on chronic renal insufficiency, seizures and deterioration of the level of consciousness. She also had hypertension, hypothyroidism and nephrotic range proteinuria. Kidney biopsy revealed many sclerotic glomeruli and focal segmental glomerulosclerosis (FSGS). Glomerulopathy is rare in patients with MELAS, and FSGS has been reported only in a few patients. The histopathological features of the renal biopsy suggested that the aetiology of the FSGS may have been secondary to chronic renal injury rather than from a primary immunologic cause. Moreover, our case is unique in that, the coexistence of MELAS, hypothalamic hypothyroidism and FSGS has not been reported in the past. The purpose of this report is to increase the awareness of health-care professionals, especially in the fields of paediatrics, neurology, endocrinology and nephrology, regarding the manifestations and complications of MELAS.

Renal manifestations of primary mitochondrial disorders

“…Chronic renal failure was the indication for renal transplantation in a 58-year-old male with MELAS syndrome (17). In a 13-year-old Asian female with MELAS syndrome, renal involvement manifested as FSGS (18). In another MELAS patient acute renal failure occurred and was associated with severe hyponatriemia due to renal sodium loss (19).…”

Mitochondrial Encephalopathy, Lactic Acidosis, and Strokelike Episodes

“…A child with MELAS who developed FSGS similarly demonstrated signs of a chronic vasculopathy consistent with a hypertensive nephropathy. No definite immune complexes or fibrillary‐type deposits were apparent under electron microscopy, suggestive of a nonimmunogenic etiology 69 …”

Renal manifestations of genetic mitochondrial disease

“…Renal tubular dysfunction and tubulointerstitial nephritis are less common findings on kidney biopsy. While kidney disease due to mitochondrial point mutations has occasionally been reported in the absence of extrarenal features, 13,23 it more commonly occurs in the setting of MELAS syndrome 14,[24][25][26][27][28] or deafness, which usually occurs with diabetes. 11,12,26,[29][30][31][32][33][34][35] Point mutations that occur in a protein-coding region of mtDNA in association with a kidney phenotype are very rare.…”