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Background. Adult-type hypolactasia (lactase non-persistence) is a common cause of gastrointestinal symptoms. Several DNA sequence variants have been identified for the lactase-persistence/non-persistence (LP/LNP), the most common being the C to T residing -13910 bp upstream of the lactase gene (LCT). We have analysed sequence variants of LP/LNP in subjects originating from Northern Russia. Methods. A total of 148 subjects with gastrointestinal complaints were genotyped covering about 400 bp around the -13910C/T variant using direct PCR-sequencing. All patients were interviewed about milk-related symptoms using the questionnaire. Disaccharidase activities were measured from intestinal biopsy specimens of the index person. Results. The prevalence of the -13910C/C genotype among 148 patients was 28.4%. A G to A variant residing 13914 bp upstream from the LCT gene (-13914G>A) was identified in one participant carrying the -13910C/C genotype. In two biopsy specimens her lactase activity was above the generally accepted cut off level for adult-type hypolactasia, 10U/g protein. Three other family members also carried the -13914G>A genotype. Among eight family members five had the LNP genotype -13910C/C. Conclusion. A rare variant G to A residing 13914 bp upstream of the LCT gene was identified in a subject carrying the more frequent variant -13910C/C. The -13914G>A variant in heterozygous state was associated with increased lactase activity, suggesting that the increased lactase activity is most likely to be associated with the -13914G>A variant. Further studies need to be done to confirm the functional role of this variant. [ABSTRACT FROM AUTHOR]

The article presents a study on molecular diagnosis of adult-type hypolactasia. Diagnosis of adult-type hypolactasia is usually required in populations where lactose-containing dairy products are commonly used. The diagnosis of adult-type hypolactasia is by definition based on the measurement of lactase, sucrase and maltase activities and the lactase/sucrase ratio in intestinal biopsies. A wide spectrum of indirect functional tests have been used for adult-type hypolactasia the most commonly used being the lactose tolerance test and breath hydrogen test.

Background. The rising role of nucleic acid testing in clinical decision making is creating a need for efficient and automated diagnostic nucleic acid test platforms. Clinical use of nucleic acid testing sets demands for shorter turnaround times (TATs), lower production costs and robust, reliable methods that can easily adopt new test panels and is able to run rare tests in random access principle. Here we present a novel home-brew laboratory automation platform for diagnostic mutation testing. Method. This platform is based on the cyclic minisequecing (cMS) and two color near-infrared (NIR) detection. Pipetting is automated using Tecan Freedom EVO pipetting robots and all assays are performed in 384-well micro plate format. The automation platform includes a data processing system, controlling all procedures, and automated patient result reporting to the hospital information system. Conclusions. We have found automated cMS a reliable, inexpensive and robust method for nucleic acid testing for a wide variety of diagnostic tests. The platform is currently in clinical use for over 80 mutations or polymorphisms. Additionally to tests performed from blood samples, the system performs also epigenetic test for the methylation of the MGMT gene promoter, and companion diagnostic tests for analysis of KRAS and BRAF gene mutations from formalin fixed and paraffin embedded tumor samples. Automation of genetic test reporting is found reliable and efficient decreasing the work load of academic personnel. [ABSTRACT FROM AUTHOR]

About 70% of the world's adult population is unable to digest lactose, the sugar found naturally only in milk. This disability leads to gastrointestinal symptoms called lactose intolerance. In Finland, many patients visit health care centres because they are suffering from gastrointestinal symptoms. A few of them are diagnosed as being lactose intolerant. However, a far larger number diagnose themselves as suffering from lactose intolerance. Therefore the diagnostic tests used should be carefully validated and standardized in clinical laboratories throughout the country. The aim of this questionnaire study was to clarify the situation centres with adult patients in Finnish health care and to try to standardize procedures for administering lactose tolerance tests. [ABSTRACT FROM AUTHOR]

In lactose maldigesters, retarding gastric emptying (food/pharmaceuticals) improves tolerance to lactose. The role of temperature of test solution on the indicators of lactose intolerance was studied. After an overnight fast, 10 lactose maldigesters ingested, in three sessions, 50 g lactose in a randomized cross-over trial. The solutions were at temperatures of 20-21°C (room temperature), 2-3°C (cold) and 55-58°C (hot). Gastrointestinal symptoms and indicators measuring lactose absorption were recorded. Abdominal pain was noticeably increased by the modification of temperature. The cold solution reduced flatulence and abdominal bloating, whereas the hot solution increased bloating and borborygmi. Breath hydrogen excretion tended to be augmented and retarded after cold solution. The temperature of the solution used in a lactose tolerance test affects the gastrointestinal symptoms, but has only minor effects on the other indicators of lactose maldigestion. The constant tendencies observed suggest that a room temperature solution is to be recommended for testing lactose digestion. [ABSTRACT FROM AUTHOR]

The measurement of hydrogen in exhaled air and changes in the concentration of blood glucose and urine galactose excretion are indirect methods of diagnosing hypolactasia. The aim of this study was to compare a portable breath hydrogen analyser (Micro H) with a widely used model (Quintron MicroLyzer) and to compare them with the blood glucose, urine galactose, and gastrointestinal symptoms in the lactose tolerance test. After an overnight fast, 44 volunteers (18 - 66 y) ingested 50 g lactose in a single oral dose. Changes in exhaled breath hydrogen concentrations were measured with the two analysers, and changes in blood glucose and urinary galactose were assayed for 4 h and used as a reference. Eighteen subjects were diagnosed as maldigesters according to our gold standard of at least two positive tests out of the three: breath hydrogen by Quintron, blood glucose concentration, and urine galactose excretion. The highest increase in the breath hydrogen concentration over the baseline was highly variable: 44 - 366 ppm (Micro H) or 27 - 187 ppm (Quintron MicroLyzer). The sensitivity, specificity, and positive and negative predictive values of the Micro H compared to the gold standard were 83%, 96%, 94% and 89%, respectively. Overall agreement was 91% (95% CI 78 - 97%). Compared to the Quintron, the diagnoses were identical in 100% of the cases (92 - 100%). Thus, for diagnosing hypolactasia, the Micro H appeared as reli­-able for measuring breath hydrogen concentrations as Quintron MicroLyzer commonly used in oral lactose tolerance tests. [ABSTRACT FROM AUTHOR]