A Genetic Lab-on-Phone Test for Point-of-Care Diagnostic of Lactose Intolerance near Patient and in less than 90 Minutes
Mariana Conceição, Hugo Assunção, Gonçalo Doria, Eduardo Coelho, Carla Clemente, César Gaspar, Tiago Furtado, Takumi Yamaguchi, António Santos, Mónica Silva, Lidia Rodriguez, Liliana Rodrigues, Orfeu Flores- General Medicine
Abstract
Background
The −13910 C/T single nucleotide polymorphism located within the MCM6 gene, an enhancer region located upstream of the lactase-phlorizin hydrolase gene, is associated with lactase persistence/non-persistence traits among the Caucasian population. The performance of a new point-of-care CE-IVD (In Vitro Diagnostic) marked isothermal lab-on-phone lactose intolerance assay, using crude samples, was assessed in comparison with Sanger sequencing using purified DNA, as reference method.
Methods
The study was conducted following a non-probability sampling using direct buccal swab (n = 63) and capillary blood (n = 43) clinical samples from a total of 63 volunteers. A 3 × 3 confusion matrix/contingency table was used to evaluate the performance of the isothermal lab-on-phone lactose intolerance assay.
Results
The isothermal lab-on-phone lactose intolerance assay successfully detected the −13910 C/T variant with a limit of detection of 5 cells/assay and demonstrated an overall accuracy of 98.41% (95% CI, 91.47%–99.96%) for buccal swab samples and 100% (95% CI, 91.19%–100%) for capillary blood, taking just 90 min from sample to result, with only 2 min hands-on.
Conclusions
The lab-on-phone pocket-sized assay displayed good performance when using direct buccal swab and capillary blood samples, enabling a low-cost, real-time, and accurate genotyping of the −13910 C/T region for the rapid diagnosis of primary lactose intolerance at point-of-care, which enables a prompt implementation of appropriate diet habits and/or intolerance therapies. To our knowledge, this is the first point-of-care genetic test for lactose intolerance to be made available on the market.