Objective:To investigate the influence of genetic and environmental factors on the clinical characteristics of upper urinary tract calculi in pediatric patients.Methods:This study was a retrospective case series. The clinical data of 179 children under the age of 14 with upper urinary tract calculi treated at Beijing Friendship Hospital，Capital Medical University，from August 2014 to February 2023 were analyzed. There were 121 males（67.60%）and 58 females（32.40%），with a median age at onset of 2.10（1.14，5.17）years. Thirty-three cases（18.44%）had a family history of urinary stone disease. Stone characteristics was defined by CT，with a median stone burden（sum of the diameters of all stones）of 1.3（1.00，1.60）cm. Fifty-four（30.17%）children had staghorn calculi. Multiple stones were present in 92 cases（51.40%），and bilateral stones in 52 cases（29.05%），with hydronephrosis was present in 119 children（66.48%）. The median follow-up time was 67 months，and 36 children（20.11%）experienced stone recurrence. Dietary habits and related information were collected by electronic questionnaire，including a total of 115 children（64.25%）with an unbalanced diet，101（56.42%）with insufficient water intake，and 32 children（17.88%）with a preference for a high-protein diet. Tap water was used as the source of drinking water by 128 patients（71.51%），and 107（59.78%）took dietary supplements. Whole-exome sequencing revealed that 55 children（30.73%）carried pathogenic mutations in stone-related genes. Binary logistic regression was used for univariate analysis of above risk factors. Variables with P < 0.1 in univariate analysis and without multicollinearity were included in multivariate logistic regression to further screen for independent risk factors. Results:Multivariate analysis confirmed that carrying stone-related pathogenic gene mutations（ OR = 3.06，95% CI 1.25?7.45， P = 0.014）and insufficient water intake（ OR = 3.28，95% CI 1.14?9.47， P = 0.028）were independent risk factors for higher stone burden. A high-protein diet（ OR = 2.40，95% CI 1.03?5.63， P = 0.044），carrying stone-related pathogenic gene mutations（ OR = 4.57，95% CI 2.21?9.46， P<0.01），and a family history of stones（ OR = 3.18，95% CI 1.28 ~ 7.91， P = 0.013）were independent risk factors for staghorn calculi. Multiple stones were closely associated with a family history of stones（ OR = 2.66，95% CI 1.15-6.17， P = 0.022）and carrying stone-related pathogenic gene mutations（ OR = 3.22，95% CI 1.60-6.48， P = 0.001）. Moreover，carrying stone-related pathogenic gene mutations（ OR = 5.19，95% CI 2.52?13.82， P < 0.01）were an independent risk factor for stone recurrence，whereas dietary supplement intake was a protective factor（ OR = 0.26，95% CI 0.11?0.62， P = 0.002）. Conclusions:Genetic and environmental factors play significant roles in the occurrence and development of pediatric upper urinary tract stones. A high-protein diet as well as a positive family history of stones are independent risk factors for staghorn calculi，and insufficient water intake is a critical environmental factor for stone formation，while appropriate use of dietary supplements may help reduce the risk of stone recurrence. Genetic testing indicates that approximately 30% of children carry stone-related pathogenic gene mutations，and these patients prone to severe stone and an increased risk of recurrence.

Objective:To investigate the influence of genetic and environmental factors on the clinical characteristics of upper urinary tract calculi in pediatric patients.Methods:This study was a retrospective case series. The clinical data of 179 children under the age of 14 with upper urinary tract calculi treated at Beijing Friendship Hospital，Capital Medical University，from August 2014 to February 2023 were analyzed. There were 121 males（67.60%）and 58 females（32.40%），with a median age at onset of 2.10（1.14，5.17）years. Thirty-three cases（18.44%）had a family history of urinary stone disease. Stone characteristics was defined by CT，with a median stone burden（sum of the diameters of all stones）of 1.3（1.00，1.60）cm. Fifty-four（30.17%）children had staghorn calculi. Multiple stones were present in 92 cases（51.40%），and bilateral stones in 52 cases（29.05%），with hydronephrosis was present in 119 children（66.48%）. The median follow-up time was 67 months，and 36 children（20.11%）experienced stone recurrence. Dietary habits and related information were collected by electronic questionnaire，including a total of 115 children（64.25%）with an unbalanced diet，101（56.42%）with insufficient water intake，and 32 children（17.88%）with a preference for a high-protein diet. Tap water was used as the source of drinking water by 128 patients（71.51%），and 107（59.78%）took dietary supplements. Whole-exome sequencing revealed that 55 children（30.73%）carried pathogenic mutations in stone-related genes. Binary logistic regression was used for univariate analysis of above risk factors. Variables with P < 0.1 in univariate analysis and without multicollinearity were included in multivariate logistic regression to further screen for independent risk factors. Results:Multivariate analysis confirmed that carrying stone-related pathogenic gene mutations（ OR = 3.06，95% CI 1.25?7.45， P = 0.014）and insufficient water intake（ OR = 3.28，95% CI 1.14?9.47， P = 0.028）were independent risk factors for higher stone burden. A high-protein diet（ OR = 2.40，95% CI 1.03?5.63， P = 0.044），carrying stone-related pathogenic gene mutations（ OR = 4.57，95% CI 2.21?9.46， P<0.01），and a family history of stones（ OR = 3.18，95% CI 1.28 ~ 7.91， P = 0.013）were independent risk factors for staghorn calculi. Multiple stones were closely associated with a family history of stones（ OR = 2.66，95% CI 1.15-6.17， P = 0.022）and carrying stone-related pathogenic gene mutations（ OR = 3.22，95% CI 1.60-6.48， P = 0.001）. Moreover，carrying stone-related pathogenic gene mutations（ OR = 5.19，95% CI 2.52?13.82， P < 0.01）were an independent risk factor for stone recurrence，whereas dietary supplement intake was a protective factor（ OR = 0.26，95% CI 0.11?0.62， P = 0.002）. Conclusions:Genetic and environmental factors play significant roles in the occurrence and development of pediatric upper urinary tract stones. A high-protein diet as well as a positive family history of stones are independent risk factors for staghorn calculi，and insufficient water intake is a critical environmental factor for stone formation，while appropriate use of dietary supplements may help reduce the risk of stone recurrence. Genetic testing indicates that approximately 30% of children carry stone-related pathogenic gene mutations，and these patients prone to severe stone and an increased risk of recurrence.