Rapid Communication
Copyright ©2007 Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Jul 7, 2007; 13(25): 3508-3512
Published online Jul 7, 2007. doi: 10.3748/wjg.v13.i25.3508
Correlation of intestinal disaccharidase activities with the C/T-13910 variant and age
Nabil Sabri Enattah, Mikko Kuokkanen, Carol Forsblom, Sirajedin Natah, Aino Oksanen, Irmä Järvelä, Leena Peltonen, Erkki Savilahti
Nabil Sabri Enattah, Mikko Kuokkanen, Leena Peltonen, Department of Molecular Medicine, National Public Health Institute, Helsinki, Finland, and Department of Medical Genetics, University of Helsinki, Finland
Carol Forsblom, the Folkhälsan Research Center, Helsinki; Division of Nephrology, and Division of Internal Medicine, Department of Medicine, Helsinki University Central Hospital
Sirajedin Natah, Department of Physiology, Biophysics and Medicine (GI Division), Gastrointestinal Research Group, Health Sciences Center, University of Calgary, Alberta, Canada
Aino Oksanen, Herttoniemi Hospital, Helsinki, Finland
Irmä Järvelä, Laboratory of Molecular Genetics, Helsinki University Central Hospital, Helsinki, Finland
Erkki Savilahti, Hospital for Children and Adolescents, University of Helsinki, Helsinki, Finland
Author contributions: All authors contributed equally to the work.
Supported by a grant from the Emil Aaltonen Foundation, Tampere, the Sigrid Jusélius Foundation, Helsinki, the Center of Excellence in Disease Genetics of the Academy of Finland, Helsinki University Research Funding, Helsinki, and Finnish Cultural Foundation, Helsinki, Finland
Correspondence to: Dr. Nabil Sabri Enattah, Department of Molecular Medicine, National Public Health Institute, Haartmaninkatu 8, PO Box 104, FIN-00251 Helsinki. nabil.enattah@ktl.fi
Telephone: +358-9-47448271 Fax: +358-9-47448480
Received: February 22, 2007
Revised: February 23, 2007
Accepted: March 28, 2007
Published online: July 7, 2007
Abstract

AIM: To correlate the C/T-13910 variant, associated with lactase persistence/non-persistence (adult-type hypolactasia) trait, with intestinal disaccharidase activities in different age groups of the adult population.

METHODS: Intestinal biopsies were obtained from 222 adults aged 18 to 83 years undergoing upper gastrointestinal endoscopy because of unspecified abdominal complaints. The biopsies were assayed for lactase, sucrase and maltase activities and genotyped for the C/T-13910 variant using PCR-minisequencing.

RESULTS: There was a significant correlation between lactase activity and the C/T-13910 variant (P < 0.00001). The mean level of lactase activity among subjects with C/C-13910 genotype was 6.86 ± 0.35 U/g, with C/T-13910 genotype 37.8 ± 1.4 U/g, and with T/T-13910 genotype 57.6 ± 2.4 U/g protein, showing a trimodal distribution of this enzyme activity. Significant differences were also observed in maltase activities among individuals with different C/T-13910 genotypes (P = 0.005). In contrast, in sucrase activity, no significant differences emerged between the C/T-13910 genotypes (P = 0.14). There were no statistical differences in lactase (P = 0.84), sucrase (P = 0.18), or maltase activity (P = 0.24) among different age groups. In the majority (> 84%) of the patients with the C/C-13910 genotype associated with lactase non-persistence, the lactase activity was less than 10 U/g protein.

CONCLUSION: Our study demonstrates a statistically significant correlation between the C/T-13910 genotype and lactase activity and this correlation is not affected by age in adults but the cut-off value of 20 U/g protein used for the diagnosis of lactase non-persistence might be too high.

Keywords: Adult-type hypolactasia, Lactase persistence, Disaccharidase activities, C/T-13910 genotype, Age