3 Original article Folia Med. Fac. Med. Univ. Saraeviensis 2017; 52(1): 3-8 foliamedica.mf.unsa.ba First Bosnian study of LCT -13910C>T and -22018G>A single nucleotide polymorphisms associated with adult-type lactose intolerance Grażyna Adler 1 , Mateusz Adler 2 , Amina Valjevac 3 , Mirela Mačkić-Đurović 4 , Emina Kiseljaković 5 1 Department of Gerontobiology, Pomeranian Medical University, Szczecin, Poland 2 Warsaw School of Economics, Warsaw, Poland 3 Department of Physiology, Faculty of Medicine, University of Sarajevo, Sarajevo, Bosnia and Herzegovina 4 Center for Genetics, Faculty of Medicine University of Sarajevo, Sarajevo, Bosnia and Herzegovina 5 Department of Medical Biochemistry, Faculty of Medicine, University of Sarajevo, Sarajevo, Bosnia and Herzegovina Submitted: 9.4.2017. / Accepted: 12.6.2017. *Corresponding author Grażyna Adler Department of Gerontobiology, Pomeranian Medical University, Żołnierska 48, 71210 Szczecin, Poland e-mail: gra2@op.pl ABstract Objectives: It is suggested, that over the last 1x10 4 years most ancient Europeans, have not been able to digest milk as adults. Lactose tolerance (lactase persistence) is an example of conver- gent evolution due to strong selective pressure resulting from shared cultural traits-animal domestication and adult milk con- sumption. Tis phenotype varies widely in humans, as a func- tion of ethnicity. Recent reports have identifed that a genet- ic polymorphisms -13910C>T and -22018G>A of LCT gene are closely associated with lactase persistence (LP) and lactase non-persistence (LNP) phenotypes. We sought to assess the prevalence of 13910C>T and -22018G>A variants of LCT gene in Bosnian subjects. Methods: Te subjects of the study consisted of 151 unrelated subjects from Bosnia and Herzegovina (60 males and 91 fe- males). Te mean age of the study sample was 48.0±16.4) years. PCR-RFLP was used to study of genotype and allele distribu- tion. Data were analyzed using the Stat View computer software version 5.0 (SAS Institute Inc. Cary, NC, USA). Electronic databases including Medline and Embase were searched from 1995 to February 2017. Results: Te genotypes linked to the LP phenotype were found in 74 (41.0%) of the 151 subjects. Te frequency of -13910T and -22018A alleles of LCT gene was 24.8% and 24.5%, re- spectively. Te CC/GG genotype, related to LNP was found in 77 (51.0%) individuals. Conclusion: In studied European populations we observed a linear, gradually increasing trend in the frequency of -13910T allele from South to North (Pearson’s test: 0.5728 , P-val- ue<0.001 ), and Bosnian population perfectly fts into this pat- tern. Keywords: LPH-1, lactase persistence, lactase non-per- sistance, population genetics © 2017 Folia Medica Facultatis Medicinae Universitatis Saraeviensis. All rights reserved. Introduction Lactose is a disaccharide from mammalian milk, and human milk contains the highest concentration of it, 7%. Milk sugar, lactose is hydrolyzed into the absorb- able monosaccharides, glucose and galactose by lactase (LCT) or more precisely lactase-phlorizin hydrolase-1 (LPH-1) [1]. Lactose intolerance is a worldwide phenomenon that has been widely studied over the years in order to un- derstand the infuences of human evolution and mi- gration over the ages. Te LCT activity is high during infancy but in most mammals, including most humans decreases after weaning. However, in some humans, es- pecially those from populations with a history of dairy- ing, lactase is expressed throughout adulthood. Tis trait is called lactase persistence (LP) and may have its roots in the Neolithic period [2]. During the Neolithic period, milk consumption be- came common even among adults, especially in the agriculturally developed areas. In northern Europe, particularly in the populations of the British, Scandi- navians and Germans with long history of pastoralism and milking, unprocessed milk were consumed. How- ever, milk consumption in adults was not common in Southern Europe, such as the Mediterranean region. Even nowadays, lactose intolerance is rarely seen in the British, Germans and Scandinavians but is common- ly seen in southern European populations. Terefore,