Urinary calculi in children

Urinary calculi in children


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From the Departments Government Hospital,


of Pediatrics and Urology, Nahariya, Israel

ABSTRACT - Forty-seven cases of urinary calculi were seen, in children from the Western Galilee region, in the last thirteen years. This disease was found in very high frequency in Oriental Jewish children, as well as in Arab children (0.29/1,000 and 0.26/1,000, respectively), and is rare in Jewish children of Ashkenazic European origin (O.O4ll,OOO).These facts were known from previous studies. The striking finding in this survey was the high family incidence of urinary calculi. In 21 of 47 cases from this series one or more family members (up to second cousins) were affected by the same disease. The etiology of “idiopathic” urinary calculi in cases in which no metabolic defect is found was never clearly established. This study suggests that hereditary factors have great importance in a population with a high incidence of this disease.

Urinary calculi are known to appear with varying frequency in different parts of the world. The regions where this disease is relatively common used to be called “stone belt”; the Middle East is situated in such an area.’ The occurrence of urinary calculi with a greater frequency in some places was never clearly understood. Many hypotheses were forwarded, but no clear cause was ever established.2-4 Climatic conditions were often believed to play a role in the formation of urinary calculi by dehydration in areas with high temperatures.5 Drinking habits, as well as nutrition, were also considered as possible etiologic factors in this disease. 6 Several pathologic conditions are known to predispose to the formation of calculi such as infection of the urinary tract, malformations, and immobilization; however this could hardly explain the increased incidence of this disease in certain regions. Some of the urinary calculi are due to metabolic disturbances such as cystinosis, oxalosis, renal tubular acidosis, and hyperthyroidism. All these diseases are genetically transmitted. How-






ever, in the so-called “idiopathic” stones the metabolic studies did not reveal any disturbance, and the basic cause remained unknown.7*8 Genetic predisposition has been mentioned repeatedly in the literature in the causation of this disease but has never been clearly proved as the primary cause. ‘,l” The incidence of urinary calculi in Israeli children is considered to be very high, as shown by several surveys. ‘l-l3 They also point out a clear difference of this disease in children of various ethnic origins. It is rare among Jewish children of Ashkenazic origin and relatively common in Oriental Jewish children, as well as Arab children. Urinary calculi are known to be common in children of the Western Galilee. A survey was performed to collect all the known cases of this disease in children of that region and to examine these data and parameters. Material

and Results

The survey comprises all cases calculi in children up to age thirteen

of urinary years from


Western Galilee diagnosed between the years 1968 to 1980. They were collected from the archives of the Government Hospital, Nahariya, as well as other hospitals in northern Israel, from the Infant Welfare Stations, and Worker’s Sick Fund clinics. Forty-seven cases were found, and all of them were hospitalized. The diagnosis was confirmed by intravenous pyelography. All children were operated on and the stones removed. The children’s ages ranged between one and thirteen years, with a peak incidence at seven years. Four children were younger than three years. There were 28 males and 19 females. In all cases blood studies were performed but did not reveal any metabolic defect. Calcium and phosphorus levels in the blood were within normal limits, urea nitrogen, creatinine, and uric acid were not elevated. The urinalysis was normal; aminoaciduria was not present in any case. Only cases with “idiopathic stones” were considered in this survey, one family with cystinuria and cystine calculi were not included. The chemical analysis of the stones was performed in 18 cases only; all were either calcium oxalate or calcium phosphate. Congenital malformations were discovered in 5 children: there was double ureter without dilatation or reflux (2 cases), mild stricture of the ureteropelvic junction (2 cases), and horseshoe kidney (1 case). The distribution of children by their ethnic origin is presented in Table I, and the frequency was calculated by the number of children in the relative population up to thirteen years of age. A clear difference was shown in the incidence of this disease between the Jewish children of Ashkenazic origin on one hand and Oriental Jewish children, Druze, Moslems, and ChristianArabs on the other. The differences were statistically significant (X2 = 3.5; p < 0.05). An important finding was the high incidence of urinary calculi in other members of the family of the affected children. A detailed family history of


Distribution of cases by ethnic origin

Origin Ashkenazic Jews OritintalJews

Druze Moslems Christian Arabs


No. of Cases

Children at Risk

1 9 7

26,000 31,000 33,000

23 7

74,000 35,ooo

Frequency 0.04/1000 0.29/1000 0.21/1000 0.31/1000 0.20/1000

TABLE II. Frequency

Origin Ashkenazic Jews Oriental Jews Druze Moslems Christian Arabs TOTALS

of family incidence

No. of Cases

Cases with Urinary Calculi in Family Members



9 7 23 _ 7

3 2



5 21

urinary calculi was obtained in all family members up to second cousins. In 21 families of the 47 children from this series, other cases of urinary calculi were found. In 5 families more than one member was affected with this disease. The frequency of the family incidence is presented in Table II. Comment The low incidence of urinary calculi among children of Ashkenazic origin and the relative high incidence of this disease in Oriental Jewish children and Arab children in Israel was noted in previous reports. ‘-11 However, no conclusive cause was found to explain this difference. Levi and Falk” proposed the theory that the principal cause of the high incidence of this disease in Arab children as well as in children of the Eastern Jewry group is related to deficient diet. Their survey was done between the years 1949 and 1956, and at that time there may have been an insufficient food intake in children from the lower income group. During the last decade this situation changed dramatically, and the infant and children’s diet is well adjusted in all population groups. There were no undernourished children in our cases, at the time of the appearance of symptoms or prior to admission. Moreover, the striking low incidence of this disease in Ashkenazic Jewish children and the high incidence among Arab and Oriental Jewish children is the same as twenty to thirty years ago. Stark13 who also found a striking difference in the incidence of this disease among the children of various ethnic groups in Israel suggested a combination of genetic and socioeconomic factors as an explanation. He stressed the necessity of further studies of this problem. High temperatures and consequent dehydration with insufficient fluid intake were mentioned as possible reasons for the high incidence



of urinary calculi in certain areas. However, not all regions where this disease is common have a warm climate. Moreover this mechanism could not explain the different frequency of the stone among children of various ethnic groups living under the same climatic conditions. Living habits and clothing have also been mentioned as causes of urinary calculi. Although differences in living conditions may be found in adults from different ethnic groups, these differences are of much less importance in the pediatric age group. Children drink according to their needs and do not differ in their clothing. Infection of the urinary tract appears with the same frequency in all ethnic groups, and therefore this condition also could not explain the differences found among children in this country. The striking finding in this survey was the high incidence of the same disease in other family members of the children included in this series. In 21 of 47 cases, there were one or more family members with the same disease. This fact certainly could not be explained as an accidental finding since the disease appears in the Israeli population with a frequency of 3 cases per 10,000 inhabitants.’ A genetic predisposition may therefore be supposed in the etiology of urinary calculi, and this may explain the differences in the incidence of the disease in children from various ethnic origins living in the same area. Several diseases are known to occur in Oriental Jews as well as in Arabs. These diseases, e.g., G-6-PD deficiency, familial Mediterranean fever, and some others, are transmitted by an autosomal recessive gene. This cannot be stated for the idiopathic urinary calculi where a plurifactorial etiology appears probable.








This survey showed a high incidence of urinary calculi in a certain population group with a high percentage of familial incidence. It seems, therefore, that the genetic factor has a great importance in the etiology of this disease. It appears worthwhile to investigate all the families of patients with urinary stones in order to study the possibility and the mechanism of genetic transmission of this disease. Nahariya, Israel (DR.


References 1. Frank M, et al: Epidemiological investigations of urolithiasis in Israel, J Ural 81: 497 (1959). 2. Butt AJ: Pathogenesis of renal lithiasis, a working hypothesis in etiological factors in renal lithiasis, Charles C Thomas, Springfield Ill (1956). 3. Prein EL: The riddle of urinary stone disease, JAMA 216: 503 (1971). 4. Straffon BA, and Higgins CC: Urolithiasis, in Campbell MF, and Harrison JH (Ed): Urology, 3rd ed, Philadelphia, WB Saunders Co., 1970. 5. Prince CL, Scardins PL, and Walon CT: The effect of temperature, humidity and dehydration in the formation of renal calculi, J Urol 75: 269 (1956). 6. Vermontere V: The occurrence of renal calculi and their uossible relation to diet, IAMA 109: 857 (1937). 7. Hendry WF: Recent Advances in Urology, Edinburgh, Churchill and Livingston, 1976. 8. Scholten HG, Bakker NJ, and Cornil C: Urolithiasis in childhood, J Urol 169: 744 (1973). 9. Resnick M, Pridgen DB, and Goodman HO: Genetic predisposition to formation of calcium oxalate renal calculi, N Engl J Med 278: 1313 (1968). 10. McGeown MG: Heredity in renal stone disease, Clin Sci 19: 465 (1960). 11. Levi D, and Falk W: Urinary calculus disease among Israeli immigrants and Arab children, J Pediat 51: 494 (1957). 12. Stark H: Childhood urolithiasis in Northern Israel, Isr J Med Sci 6: 341 (1970). 13. IDEM: Epidemiologic aspect of childhood urolithiasis in Israel, Pediatrician 6: 158 (1977).