title: Diagnosis of genetic predisposition for lactose intolerance by high resolution melting analysis.
abstract: Lactose, the principle sugar in milk, is a disaccharide hydrolyzed by intestinal lactase into glucose and galactose, which are absorbed directly by diffusion in the intestine. The decline of lactase expression (or hypolactasia) in intestinal microvilli after weaning is a normal phenomenon in mammals known as lactase deficiency. It is observed in nearly 75% of the world population and is an inherited autosomal recessive trait with incomplete penetrance. It is caused by SNPs in a regulatory element for lactase gene. In Indo-European, lactase deficiency is associated with rs4982235 SNP (or -13910C>T). The aim of this study is to describe a method based on high resolution melting for rapidly detecting genetic predisposition to lactose intolerance. Analytical performance of the assay was assessed by evaluating within and betwwen-run precision and by comparing the results (n = 50 patients) obtained with the HRM assay to those obtained with the gold standard (Sanger sequencing of the region of interest). In silico prediction of HRM curves was performed to evaluate the potential impact of the other SNPs described within the PCR product on the HRM analytical performances. The assay has good performance (CV <0.2% during the between-run study). A perfect agreement with the gold standard method was observed. The presence of other polymorphisms within the amplified sequence is detected, the misclassification risk is low. This assay can be used for rapidly diagnosing genetic predisposition to lactose intolerance.
authors.affiliation: Département de biologie, Hôpital d'Instruction des armées Bégin, Saint Mandé, France.
authors.forename: Hervé
authors.initials: H
authors.lastname: Delacour
authors.affiliation: Département de biologie, Hôpital d'Instruction des armées Bégin, Saint Mandé, France.
authors.forename: Amandine
authors.initials: A
authors.lastname: Leduc
authors.affiliation: Département de biologie, Hôpital d'Instruction des armées Bégin, Saint Mandé, France.
authors.forename: Andréa
authors.initials: A
authors.lastname: Louçano-Perdriat
authors.affiliation: Département de biologie, Hôpital d'Instruction des armées Bégin, Saint Mandé, France.
authors.forename: Julie
authors.initials: J
authors.lastname: Plantamura
authors.affiliation: Département de biologie, Hôpital d'Instruction des armées Bégin, Saint Mandé, France.
authors.forename: Franck
authors.initials: F
authors.lastname: Ceppa
mesh_terms: D000328:Adult; D004252:DNA Mutational Analysis / Q000379:methods*; D020022:Genetic Predisposition to Disease; D005838:Genotype; D006801:Humans; D043322:Lactase / Q000235:genetics*; D007787:Lactose Intolerance / Q000175:diagnosis* / Q000235:genetics*; D009691:Nucleic Acid Denaturation; D016133:Polymerase Chain Reaction / Q000379:methods*; D020641:Polymorphism, Single Nucleotide; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D043322:Lactase
keywords: diagnosis; high resolution melting; hypolactasia; lactase deficiency; rs4988235