Perspectives for Early Genetic Screening of Lactose Intolerance: - 13910C/T Polymorphism Tracking in the MCM6 Gene

Marta A.S. Arroyo1, Ana Cláudia P. Lopes2, Vania B. Piatto*, 1, José Victor Maniglia1
1 Department of Otorhinolaryngology of Medical School of São José do Rio Preto (FAMERP), Brazil
2 Department of Morphology of Medical School of São José do Rio Preto (FAMERP), Brazil

© 2010 Arroyo et al.

open-access license: This is an open access article distributed under the terms of the Creative Commons Attribution 4.0 International Public License (CC-BY 4.0), a copy of which is available at: This license permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

* Address correspondence to this author at the Department of Otorhinolaryngology of Medical School of São José do Rio Preto, (FAMERP), São Paulo, Brazil, Av. Brigadeiro Faria Lima, n˚ 5416, Vila São Pedro, São José do Rio Preto, SP, Zip Code: 15090-000, Brazil; Tel: +55-17-32015747; E-mail:



For many years Lactose intolerance has been, considered as a universal problem in many children and adults.


The aim is to investigate the prevalence of polymorphism -13910C/T, in a neonatal tracking, for early diagnosis of lactose tolerance/intolerance. Materials and Methods: In a cross-sectional study of 310 Brazilian newborns, DNA was extracted from leukocyte umbilical cord and specific primers were used to amplify the region that encloses the -13910C/T polymorphism of the MCM6 gene, using the polymerase chain reaction and the restriction fragment length polymorphism tests.


One hundred and sixty (52%) male newborns and 150 (48%) female new borns were evaluated. Out of these, 191 (62%) presented CC genotype (lactose intolerant), 95 (31%) CT genotype, and 24 (7%) TT genotype, comprising a total of 119 (38%) lactose tolerant newborns. Accordingly the newborns´ gender distribution in relation to the phenotypes has been found; 97 (32%) of male gender and 94 (30%) of female gender lactose intolerant, and 63 (20%) male and 56 (18%) female lactose tolerant newborns, not being such distribution statistically significant (p = 0.801).


The molecular analysis made possible the identification of the presence or absence of lactase persistence variant in the Brazilian newborns. The neonatal molecular diagnosis can optimize the follow-up of positive results in newborn screening for lactose intolerance.

Keywords: Molecular analysis, MCM6 gene, lactase, lactose malabsorption, hypolactasy.