title: Lactose intolerance genetic testing: is it useful as routine screening? Results on 1426 south-central Italy patients.
abstract: Adult-type hypolactasia is a widespread condition throughout the world, causing lactose malabsorption. Several studies suggested that the identification of C/T-13910 and G/A-22018 mutations, located upstream the gene encoding the lactase-phlorizin hydrolase (LPH), is a useful tool for the differential diagnosis of hypolactasia. We evaluated the frequencies of C/T-13910 and G/A-22018 variants in a central-south Italian population and the usefulness of lactase deficiency genetic testing in the clinic practice. The genomic DNA of 1426 patients and 1000 healthy controls from central-south Italy was isolated from peripheral whole blood and genotyped for the C/T-13910 and G/A-22018 polymorphisms by high-resolution melting analysis (HRMA) and sequencing. The frequencies of genotypes in the 1426 patients analysed were as follows: 1077 CC/GG (75.5%), 287 CT/GA (20.1%), 24 TT/AA (1.7%), 38 CC/GA (2.7%). Only 64 out of 1426 (4.5%) performed also L-BHT test, 29 of which were negative for L-BHT also in presence of different genotypes. Among the 35 individuals with L-BHT positive, 34 were CC/GG and only one CT/GA. Although lactose genetic test is a good predictor of persistence/non-persistence lactase in specific population, its use in the central-south Italy population should be limited given the high prevalence of the CCGG diplotype in normal individuals.
authors.affiliation: Laboratory of Clinical Molecular and Personalized Diagnostics, Institute of Biochemistry and Clinical Biochemistry, Catholic University of the Sacred Heart, Rome, Italy. Electronic address: concetta.santonocito@rm.unicatt.it.
authors.forename: Concetta
authors.initials: C
authors.lastname: Santonocito
authors.affiliation: Laboratory of Clinical Molecular and Personalized Diagnostics, Institute of Biochemistry and Clinical Biochemistry, Catholic University of the Sacred Heart, Rome, Italy.
authors.forename: Margherita
authors.initials: M
authors.lastname: Scapaticci
authors.affiliation: Laboratory of Clinical Molecular and Personalized Diagnostics, Institute of Biochemistry and Clinical Biochemistry, Catholic University of the Sacred Heart, Rome, Italy.
authors.forename: Donatella
authors.initials: D
authors.lastname: Guarino
authors.affiliation: Department of Internal Medicine, Teaching Hospital "A. Gemelli," Catholic University of the Sacred Heart, Rome, Italy.
authors.forename: Eleonora Brigida
authors.initials: EB
authors.lastname: Annicchiarico
authors.affiliation: Laboratory of Clinical Molecular and Personalized Diagnostics, Institute of Biochemistry and Clinical Biochemistry, Catholic University of the Sacred Heart, Rome, Italy.
authors.forename: Rosalia
authors.initials: R
authors.lastname: Lisci
authors.affiliation: Laboratory of Clinical Molecular and Personalized Diagnostics, Institute of Biochemistry and Clinical Biochemistry, Catholic University of the Sacred Heart, Rome, Italy.
authors.forename: Romina
authors.initials: R
authors.lastname: Penitente
authors.affiliation: Department of Internal Medicine, Teaching Hospital "A. Gemelli," Catholic University of the Sacred Heart, Rome, Italy.
authors.forename: Antonio
authors.initials: A
authors.lastname: Gasbarrini
authors.affiliation: Laboratory of Clinical Molecular and Personalized Diagnostics, Institute of Biochemistry and Clinical Biochemistry, Catholic University of the Sacred Heart, Rome, Italy.
authors.forename: Cecilia
authors.initials: C
authors.lastname: Zuppi
authors.affiliation: Laboratory of Clinical Molecular and Personalized Diagnostics, Institute of Biochemistry and Clinical Biochemistry, Catholic University of the Sacred Heart, Rome, Italy. Electronic address: ecapoluongo@rm.unicatt.it.
authors.forename: Ettore
authors.initials: E
authors.lastname: Capoluongo
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D002675:Child, Preschool; D005820:Genetic Testing / Q000379:methods*; D014644:Genetic Variation / Q000235:genetics; D005838:Genotype; D059014:High-Throughput Nucleotide Sequencing; D006801:Humans; D007223:Infant; D007558:Italy; D007787:Lactose Intolerance / Q000235:genetics*; D007789:Lactose Tolerance Test / Q000379:methods*; D008875:Middle Aged; D016133:Polymerase Chain Reaction; D020641:Polymorphism, Single Nucleotide / Q000235:genetics; D017422:Sequence Analysis, DNA; D055815:Young Adult
keywords: Breath test; Genetic test; Lactose intolerance