RESUMO
The paper reports a rare case of alkaptonuria (AKU) with IgA nephropathy, and analyzes its clinical manifestations, imaging findings, pathological features, gene diagnosis and treatment process, so as to provide reference for the diagnosis and treatment of the disease. The clinical symptoms of the patient were mainly black urine, microscopic hematuria and proteinuria. Renal pathology showed mild mesangial hyperplasia IgA nephropathy, and renal tubular epithelial cytochrome deposition. Genetic analysis indicated that a pathogenic mutation was detected on the AKU-related homogentisate 1, 2-dioxygenase gene possibly associated with the phenotype of the patient. Genetic testing and renal pathology were effective methods to make a definite diagnosis for the case.
RESUMO
Alkaptonuria (AKU, OMIM: 203500) is a rare autosomal recessive disorder of tyrosine metabolism due to a defect of enzyme activity, homogentisate 1,2-dioxygenase (HGD). The patients with AKU initially presented with dark urine discoloration, and ochronosis and arthritis develop after third decades of life. With advances of Internet resources, web-based health seekers for rare disease are increasing. Here, we report the case of an 18-year-old boy with AKU who visited our center due to dark black urine based on self-diagnosis via web searching of this rare condition. Compound heterozygous mutations in HGD gene, IVS5+3A>C and IVS12+6T>C were identified and both of mutations were detected in his parents. Our case illustrates the utility of publicly available Internet resources for diagnosis of rare disease.