ABSTRACT
BACKGROUND: Adult-type hypolactasia is characterized by the inability to digest lactose during adulthood, due to lactase (LCT) deficiency. It is usually diagnosed by the measurement of breath hydrogen increase after a lactose load (breath hydrogen test, BHT). A substitution of C to T at position -13910 bp upstream the LCT gene (rs4988235), in a regulatory region, was found to be strongly associated with the lactase persistence phenotype in North-European populations. METHODS: We investigated the -13910 C/T polymorphism to determine LCT genotype distribution and to validate genetic testing for adult-type hypolactasia in a Southern European population. A total of 43 children referred for suspected lactose malabsorption were enrolled in the study, their parents and siblings (whole sample=112 individuals) also took the breath test, and all were enrolled for clinical monitoring and genotype determination. In addition, 125 unrelated blood donors from the same geographic area were genotyped for the calculation of allelic frequencies. The frequency of C/C genotypes was 70%. RESULTS: The correlation between the C/C genotype (which should correspond to lactose non-digesters) and positive BHT in unrelated family founders was significant (chi(2)=16.7, p<0.002). The genetic test compared to the BHT had a sensitivity of 95% and 91% and a specificity of 48% and 55% in adults and children, respectively. CONCLUSIONS: Low specificity might be due to intrinsic limitations of the standard BHT or to other possible mutations, although no sequence variation was found upon sequencing a 253 bp fragment of the LCT regulatory region in asymptomatic individuals.
Subject(s)
Genetic Testing , Lactase/deficiency , Lactose Intolerance/genetics , Polymorphism, Single Nucleotide , Adolescent , Adult , Child , Child, Preschool , Family , Female , Gene Frequency , Genotype , Humans , Italy , Lactase/genetics , Lactose Intolerance/diagnosis , Male , Middle Aged , Sensitivity and SpecificityABSTRACT
AIM: To evaluate the management of Italian children with cholelithiasis observed at Pediatric and Surgical Departments linked to Italian Society of Pediatric Gastroenterology Hepatology and Nutrition. METHODS: One-hundred-eighty children (90 males, median age at diagnosis 7.3 years; range, 0-18 years) with echographic evidence of cholelithiasis were enrolled in the study; the data were collected by an anonymous questionnaire sent to participating centers. RESULTS: One hundred seventeen patients were treated with ursodeoxycholic acid; in 8 children dissolution of gallstones was observed, but the cholelithiasis recurred in 3 of them. Sixty-five percent of symptomatic children treated became asymptomatic. Sixty-four patients were treated with cholecystectomy and in only 2 cases a postoperative complication was reported. Thirty-four children received no treatment and were followed with clinical and echographic controls; in no case the development of complications was reported. CONCLUSION: The therapeutic strategies were extremely heterogeneous. Ursodeoxycholic acid was ineffective in dissolution of gallstones but it had a positive effect on the symptoms. Laparoscopic cholecystectomy was confirmed to be an efficacy and safe treatment for pediatric gallstones.
