Background Primary lactose intolerance (PLI) is a frequent condition caused by a genetically programmed and progressive loss of lactase expression. It is considered that PLI is the ancestral variant, while lactase persistence is caused by 2 polymorphisms: the dominant C/T13910 and G/A22018. Homozygotes (CC or GG) have undetectable lactase levels. In clinical practice only half of people with PLI have symptoms. However, some studies showed that PLI subjects have lower dairy intake.

Aim To investigate whether genetic predisposition to PLI influences the quality of life and dairy intake in a group of Romanian children.

Material and methods We conducted a prospective study, recruiting consecutive children evaluated in our unit in May-August 2016. Our study population included 87 children aged 6–17 years (mean age 10.64±3.51 years), 45 (51.72%) girls. We used strip genotyping to identify genetic predisposition to IPL. Subjects were asked to complete a validated quality of life questionnaire and a dairy intake questionnaire. We used Spearman’s test to evaluate the correlation between IPL and quality of life and dairy intake.

Results 45 (51.7%) subjects had a CC genotype. 30 (34.5%) subjects had a GG genotype. Our results were consistent with Hardy-Weinberg equilibrium. We found no correlation between homozygosity for PLI and dairy intake (CC: r=−0.06, p=0.54; GG: r=−0.01, p=0.86). We found no correlation between either CC, or GG homozygosity and quality of life (r=−0.11, p=0.3 and r=−0.1, p=0.34).

Conclusions In our group genetic predisposition to IPL followed European trends. It did not influence quality of life and dairy intake.