2 Figure 1: Cysts and calculi appear on USG. Table 1: Metabolic evaluation for nephrolithiasis. Test 24-hour urine (i) Oxalate (ii) Calcium (iii) Uric acid (iv) Citrate (v) Cystine Serum (i) HCO3 (ii) Uric acid (iii) Calcium Result (i) 0.28 mmol/1.73 m2/24 h (N: < 0.56) (ii) 3.2 mg/kg/24 h (N:< 4) (iii) 9.4 mg/kg/24 h (N: < 10) (iv) 2.0 mg/kg/24 h (N: > 2) (v) 35 mg/1.73 m2/24 h (N: < 60) (i) 24 mmol/L (N: 22–28) (ii) 4.2 mg/dL (N: 1.7–5.8) (iii) 10.1 mg/dL (N: 8.8–10.8) paracetamol. Potassium citrate (2 mmol HCO3−/kg/day) was prescribed for prophylaxis of nephrolithiasis. He passed a stone in his urine at the 2nd month of followup. Stone anal- ysis by X-ray diﬀraction method was consistent with calcium oxalate calculus. Extracorporeal shock wave lithotripsy was planned for the remaining stones. 3. Discussion ADPKD is the most common hereditary kidney disease that is responsible for 5 to 10% of end-stage renal disease in adults. It has been shown that PKD1 (chromosome 16p13.3) and PKD2 mutations (chromosome 4q13q23) are causative in 85% and 15% of patients, respectively [1, 2]. In our case, mutation analysis was not performed. However, it has been reported that determination of 2 cysts in a single kidney or one cyst in each kidney in a patient under 30 years of age in a known ADPKD family is suﬃcient for diagnosis [5]. Thus, our patient was considered to have ADPKD. In ADPKD, along with the cystic alterations in the kidneys, various extrarenal ﬁndings such as cysts in the liver, spleen and ovary, mitral valve prolapses, intracranial aneurysms, diverticulosis in the colon, and abdominal hernias may be seen [4, 6]. Abdominal ultrasonography did not reveal extrarenal cysts in our patient. On the other hand, we did not screen for the presence of intracranial aneurysms Case Reports in Medicine as the family history did not reveal any cerebrovascular event [7]. Abdominal pain is a common symptom in ADKPD. Acute pain may result from bleeding into the cysts, obstruc- tion due to calculi,s or infection. Chronic abdominal pain is associated with the pressure caused by the kidneys and/or cysts. Nonnephrotoxic analgesics or cyst decompression or sclerosis may be applied in the treatment of chronic pain [1]. In our case, abdominal pain and hematuria were probably related to the presence of calculi. Hematuria disappeared spontaneously, while the pain responded to paracetamol. The prevalence of urolithiasis in ADPKD is around 20– 36 percent. Approximately half of the calculi is calcium oxalate and the other half consists of uric acid [3]. However, urolithiasis is rare in childhood and is usually seen after the second decade of life. In a study of 82 ADPKD patients, nephrolithiasis was detected in 23 (28%) patients. Forty percent and 60% of the cases were 20 to 40 years and over 40 years of age, respectively. None of the patients below 20 years of age had urolithiasis [8]. Our case is interesting in that he had 3 large and many small calculi while he was just at 11 years of age. Increased risk of urolithiasis in ADPKD is associated with both intrarenal anatomic obstruction and urinary tract infections. On the other hand, metabolic abnormalities frequently accompany urolithiasis. Most common metabolic abnormality is hypocitraturia, while hypercalciuria and hyperuricosuria are having also been reported in some cases [3]. Ultrasonographic and metabolic parameters were compared in ADPKD patients having and not having renal stone disease. It was reported that patients having calculus had more and bigger cysts, while they had lower glomerular ﬁltration rate, urine volume, urine phosphate, magnesium, citrate, and potassium levels. In both groups of patients, the rate of hypocitraturia was approximately 60 percent [9]. Our patient is probably prone to the development of urolithiasis due to the presence of numerous renal cysts and hypocitraturia. On the other hand, it has been reported that there are phenotypic diﬀerences in ADPKD families. The prevalence of hypertension and hernia along with patient and renal survivals diﬀers between the families [10]. All eﬀected family members of our patient have renal stone disease. This implicates that there may be a hereditary predisposition for renal calculus disease in this family. In conclusion, in patients with ADPKD, multiple factors contribute to the development of urolithiasis including anatomic, metabolic, and hereditary abnormalities. Presence of nephrolithiasis in this 11-year-old child indicates the importance of the evaluation and followup of even young children with ADPKD for renal stone disease. References [1] P. D. Wilson, “Polycystic kidney disease,” New England Journal of Medicine, vol. 350, no. 2, pp. 151–164, 2004. [2] C. S. Ng, A. Yost, and S. B. Streem, “Nephrolithiasis associated with autosomal dominant polycystic kidney disease: contem- porary urological management,” Journal of Urology, vol. 163, no. 3, pp. 726–729, 2000.