Asthma is a chronic and recurrent disease. Its high prevalence around the world is the result of a complex interaction between genetic and environmental factors. The genetic aspects of susceptibility, severity, and response to treatment in asthma are of great scientific interest. The purpose of the study was to establish the relationship between the Gln27Glu and Arg16Gly alleles of the β(2) -adrenergic receptor (ADRB2) gene with respect to the susceptibility to and severity of asthma, as well as the response to treatment in mestizo schoolchildren. 109 schoolchildren with asthma diagnosis and 137 asymptomatic controls were genotyped for the Arg16Gly and Gln27Glu alleles of the ADRB2 gene by minisequencing. Allele, genotype, and haplotype frequencies of the ADRB2 gene between asthmatic and non-asthmatic as well as demographic, clinical, and spirometric variables among asthmatic patients according to their genotype were compared. ADRB2 gene expression was determined by real-time quantitative PCR. No statistical differences were found in allele, genotype, and haplotype frequencies of the ADRB2 gene between cases and controls. We did not find differences between asthmatic patients classified according to their ADRB2 genotypes and haplotypes when evaluating demographic, clinical, and spirometric variables. The ADRB2 genotype and haplotype are not associated with spirometric responses or ADRB2 gene expression after administration of a β-(2) agonist plus a glucocorticoid. These results suggest that in the group of mestizo schoolchildren studied, the Arg16Gly and Gln27Glu polymorphisms are not markers of susceptibility or severity of asthma and do not affect ADRB2 gene expression during the rescue therapy.

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Colombia has a high prevalence of mucopolysaccharidosis (MPS) type IVA. Nevertheless, data regarding the mutation spectrum for MPS IVA in this population have not been completely characterized. Forty-seven families and 53 patients from seven different Colombian regions were tested for MPS IVA mutations. We compared the sequences with the N-acetylgalactosamine-6-sulfatase (GALNS) reference sequence NM_000512.4, and gene variants were reported. Bioinformatics analysis was performed using SWISS-MODEL. The mutant proteins were generated by homology from the wild-type GALNS 4FDJ template obtained from the PDB database, and visualization was performed using Swiss-PDBViewer and UCSF Chimera. The predictive analysis was run using different bioinformatic tools, and the deleterious annotation of genetic variants was performed using a neural network. We found that 79% and 21% of the cohort was homozygous and compound heterozygous, respectively. The most frequent mutation observed was p.Gly301Cys (78.3% of alleles), followed by p.Arg386Cys (10.4% of alleles). A novel mutation (p.Phe72Ile) was described and classified in silico as a pathogenic variant. This study reveals the mutation spectrum of MPS IVA in Colombia. The high prevalence of the p.Gly301Cys mutation suggests a founder effect of this variant in the Colombian population that causes diseases in the Andean region (via migration). These data can facilitate genetic counseling, prenatal diagnosis, and the design of therapeutic interventions.

Polymorphisms Arg₁₆Gly and Gln₂₇Glu of the gene of adrenoreceptor β₂(ADRB2) are associated with altered sympathetic responses. This study evaluated the relationship between these polymorphisms and changes in lipids induced by metoprolol in hypertensive patients. 105 adults were enrolled. After serum lipid levels and genotype had been determined, metoprolol was administered orally. Genotyping was performed using a mini-sequencing technique. Allelic and genotypic frequencies were: Arg₁₆ (49.5%); Gly₁₆ (50.5%); Gln₂₇ (89%); Glu₂₇ (11%); Arg₁₆Arg (28.6%); Arg₁₆Gly (41.9%); Gly₁₆Gly (29.5%); Gln₂₇Gln (81%); Gln₂₇Glu (16.1%), and Glu₂₇Glu (2.9%). Ninety patients concluded the study. There were no significant differences between the demographic, pharmacological and biochemical variables evaluated, grouped by their genotype in positions 16 and 27 of the ADRB2 gene. We did not find differences in lipid profiles in the whole group, but when we compared these profiles within each genotypic subgroup, we found that total cholesterol diminished (p = 0.03) in the patients with the native Gln₂₇Gln genotype, whereas in the Gln₂₇Glu heterozygous triglycerides increased (p = 0.025). We only found 3 patients homozygous for Glu₂₇Glu and 2 of them were treated with diet and antidyslipidemic drugs. These results suggest that the polymorphism of codon 27 constitutes the target of the changes in lipids induced by β-adrenergic receptor antagonists.

Neonatal screening in Colombia has been carried out since 2000. The problem that most concerns is the absence of expanded screening. To stablish reference values for amino acids and acylcarnitines, in order to provide information to guide the implementation of expanded screening. Samples collected on Whatman 903 filter paper from 10284 newborns were processed by Tandem Mass Spectrometry System (Waters -Perkin Elmer), and the NeoBase™ non-derivatized MS/MS kit (PerkinElmer), which contains controls for 11 amino acids, and 31 acylcarnitine species. For each analyte the upper limit was set above the 99th percentile, while the lower limit was set below the 1st percentile. Comparison of full-term newborn amino acid concentrations with premature ones showed no significant differences in three of them: Glycine p-0.99574, Ornithine p=0.35274, Phenylalanine p=0.13499, neither in levels of 11 of the 31 acylcarnitines. Comparison of analyte concentrations in this study with previous reports showed significant differences for all amino acids and acylcarnitines (<0.05). Experience was gained in the pre-analytic stage of expanded screening and reference values were established, for the implementation of neonatal screening program in the country.