A Case Report of a Patient with COQ8B Nephropathy Manifesting Atypical Renal Pathological Changes.

BACKGROUND

COQ8B nephropathy is a hereditary mitochondrial kidney disease. Most cases present with steroidresistant nephrotic syndrome and focal segmental glomerulosclerosis, whereas this patient exhibited asymptomatic isolated proteinuria and mild renal histopathology.

METHODS

Appropriate laboratory tests, abdominal ultrasonography, renal biopsy, and whole exome sequencing were performed to explore the cause of the disease.

RESULTS

Laboratory results revealed that the patient was asymptomatic. Abdominal ultrasonography confirmed left renal vein nutcracker. Renal histopathology showed mild mesangial proliferation. An unreported splice mutation in the COQ8B (c.893+2T>A) gene was identified by whole exome sequencing.

CONCLUSIONS

COQ8B nephropathy is an emerging cause of isolated proteinuria, particularly prevalent among adolescents. For nephritis of unknown etiology following renal biopsy, prompt consideration of gene sequencing is advisable.