Department of Urology, The First Affiliated Hospital of Xiamen University, Xiamen, China.
Department of Pediatric Surgery, Women and Children's Hospital, School of Medicine, Xiamen University, Xiamen, China.
BMC Urol. 2023 Jul 31;23(1):130. doi: 10.1186/s12894-023-01300-y.
Cystinuria and xanthinuria are both rare genetic diseases involving urinary calculi. However, cases combining these two disorders have not yet been reported.
In this study, we report a case of cystinuria with xanthine stones and hyperuricemia. The 23-year-old male patient was diagnosed with kidney and ureteral stones, solitary functioning kidney and hyperuricemia after admission to the hospital. The stones were removed by surgery and found to be composed of xanthine.
Genetic testing by next-generation sequencing technology showed that the patient carried the homozygous nonsense mutation c.1113 C> A (p.Tyr371*) in the SLC3A1 gene, which was judged to be a functionally pathogenic variant. Sanger sequencing revealed that the patient's parents carried this heterozygous mutation, which is a pathogenic variant that can cause cystinuria. The 24-h urine metabolism analysis showed that the cystine content was 644 mg (<320 mg/24 h), indicating that the patient had cystinuria, consistent with the genetic test results. This case shows that cystinuria and xanthine stones can occur simultaneously, and provides evidence of a possible connection between the two conditions. Furthermore, our findings demonstrate the potential value of genetic testing using next-generation sequencing to effectively assist in the clinical diagnosis and treatment of patients with urinary calculi.
胱氨酸尿症和黄嘌呤尿症都是罕见的遗传性疾病，涉及尿路结石。然而，尚未有同时合并这两种疾病的病例报告。
本研究报告了一例胱氨酸尿合并黄嘌呤结石和高尿酸血症的病例。该 23 岁男性患者入院后被诊断为肾结石和输尿管结石、孤立肾和高尿酸血症。通过手术取出结石，发现其成分是黄嘌呤。
通过下一代测序技术进行基因检测显示，该患者携带 SLC3A1 基因中的纯合无义突变 c.1113 C>A (p.Tyr371*)，该突变被判断为具有功能致病性的变异。Sanger 测序显示，患者的父母携带这种杂合突变，这是一种致病性变异，可导致胱氨酸尿症。24 小时尿液代谢分析显示胱氨酸含量为 644mg(<320mg/24h)，表明患者患有胱氨酸尿症，与基因检测结果一致。本病例表明胱氨酸尿症和黄嘌呤结石可同时发生，并为这两种疾病之间可能存在关联提供了证据。此外，我们的发现表明，下一代测序的基因检测具有潜在价值，可有效协助尿路结石患者的临床诊断和治疗。
