Coincidence of autosomal dominant polycystic kidney disease and Alport syndrome: a case report and literature review

Autosomal dominant polycystic kidney disease (ADPKD) is the most common genetic kidney disease, accounting for approximately 5% of kidney failure worldwide. While Alport syndrome (AS) is an inherited progressive disease that typically presents with microhematuria in childhood and subsequently progresses to hematuria, proteinuria, and progressive renal impairment. The coexistence of ADPKD and AS is rare. Here, we present a case of a child with ADPKD and AS who presented with bilateral renal cysts and hematuria. Furthermore, we described the clinical and genetic characteristics of the present case and summarized the above features of previously reported cases. A 4-year-old boy had persistent microscopic hematuria and intermittent gross hematuria for 1 year. During routine examinations, microscopic hematuria (++), bilateral renal cysts, and high-frequency hearing loss were discovered. Furthermore, His mother had microscopic hematuria and was later diagnosed with ADPKD. A pathogenic variant was found in COL4A5 through genetic testing, while a variant of undermined significance (VUS) was discovered in PKD1. These clinical and genetic findings are consistent with the diagnosis of ADPKD and AS co-occurring. Enalapril was administered. A 2-year follow-up revealed that the patient had continuous microscopic hematuria and normal range renal function. We also reviewed four cases of ADPKD and AS coexisting. Moreover, hematuria and decreased renal function were the most common clinical features. They all had a positive family history. This disease has a poor prognosis, with three cases progressing to kidney failure. ADPKD and AS are often associated with hematuria, renal cysts, and decreased renal function. Comprehensive clinical information and early genetic testing is critical for diagnosis, prognostic stratification, and initiating targeted therapies to delay progression.