Genetic variants associated with poor responsiveness to sulfonylureas in Filipinos with type 2 diabetes mellitus / Journal of the ASEAN Federation of Endocrine Societies

Introduction@# Sulfonylureas (SUs) are commonly used drugs for type 2 diabetes mellitus (T2DM) in the Philippines. This study aimed to associate genetic variants with poor response to gliclazide and glimepiride among Filipinos.@*Methodology@#Two independent, dichotomous longitudinal substudies enrolled 139 and 113 participants in the gliclazide and glimepiride substudies, respectively. DNA from blood samples underwent customized genotyping for candidate genes using microarray. Allelic and genotypic features and clinical associations were determined using exact statistical methods.@*Results@#Three months after sulfonylurea monotherapy, 18 (13%) were found to be poorly responsive to gliclazide, while 7 (6%) had poor response to glimepiride. Seven genetic variants were nominally associated (p<0.05) with poor gliclazide response, while three variants were nominally associated with poor glimepiride response. For gliclazide response, carboxypeptidase-associated variants (rs319952 and rs393994 of AGBL4 and rs2229437 of PRCP) had the highest genotypic association; other variants include rs9806699, rs7119, rs6465084 and rs1234315. For glimepiride response, 2 variants were nominally associated: CLCN6-NPPA-MTHFR gene cluster – rs5063 and rs17367504 – and rs2299267 from the PON2 loci.@*Conclusion@#Genetic variants were found to have a nominal association with sulfonylurea response among Filipinos. These findings can guide for future study directions on pharmacotherapeutic applications for sulfonylurea treatment in this population.

Lack of methylation changes in GJB2 and RB1 non-coding regions of cochlear implant patients with sensorineural hearing loss

Objective@#Recent advances in epigenetic studies continue to reveal novel mechanisms of gene regulation and control, however little is known on the role of epigenetics in sensorineural hearing loss (SNHL) in humans. We aimed to investigate the methylation patterns of two regions, one in RB1 and another in GJB2 in Filipino patients with SNHL compared to hearing control individuals. @*Methods@#We investigated an RB1 promoter region that was previously identified as differentially methylated in children with SNHL and lead exposure. Additionally, we investigated a sequence in an enhancer-like region within GJB2 that contains four CpGs in close proximity. Bisulfite conversion was performed on salivary DNA samples from 15 children with SNHL and 45 unrelated ethnically-matched individuals. We then performed methylation-specific real-time PCR analysis (qMSP) using TaqMan® probes to determine percentage methylation of the two regions. @*Results@#Using qMSP, both our cases and controls had zero methylation at the targeted GJB2 and RB1 regions. @*Conclusion@#Our study showed no changes in methylation at the selected CpG regions in RB1 and GJB2 in the two comparison groups with or without SNHL. This may be due to a lack of environmental exposures to these target regions. Other epigenetic marks may be present around these regions as well as those of other HL-associated genes.

Genome sequencing and detection of Philippine SARS-CoV-2 infections with viruses classified under the B.1.1.7 lineage

We report the sequencing and detection of 39 Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) samples containing lineage-defining mutations specific to viruses belonging to the B.1.1.7 lineage (UK variant) in the Philippines.

Genome sequencing and analysis of an emergent SARS-CoV-2 variant characterized by multiple spike protein mutations detected from the Central Visayas Region of the Philippines

The emergence of SARS-CoV-2 variants of concern such as the B.1.1.7, B.1.35 and the P.1 have prompted calls for governments worldwide to increase their genomic biosurveillance efforts. Globally, quarantine and outbreak management measures have been implemented to stem the introduction of these variants and to monitor any emerging variants of potential clinical significance domestically. Here, we describe the emergence of a new SARS-CoV-2 lineage, mainly from the Central Visayas region of the Philippines. This emergent variant is characterized by 13 lineage-defining mutations, including the co-occurrence of the E484K, N501Y, and P681H mutations at the spike protein region, as well as three additional radical amino acid replacements towards the C-terminal end of the said protein. A three-amino acid deletion at positions 141 to 143 (LGV141_143del) in the spike protein was likewise seen in a region preceding the 144Y deletion found in the B.1.1.7 variant. A single amino acid replacement, K2Q, at the N-terminus of ORF8 was also shared by all 33 samples sequenced. The mutation profile of this new virus variant warrants closer investigation due to its potential public health implications. The current distribution of this emergent variant in the Philippines and its transmission are being monitored and addressed by relevant public health agencies to stem its spread in nearby islands and regions in the country.

ANALYSIS OF SARS-COV-2 GENOME SEQUENCES FROM THE PHILIPPINES: GENETIC SURVEILLANCE AND TRANSMISSION DYNAMICS

The spread of the corona virus around the world has spurred travel restrictions and community lockdowns to manage the transmission of infection. In the Philippines, with a large population of overseas Filipino contract workers (OFWs), as well as foreign workers in the local online gaming industry and visitors from nearby countries, the first reported cases were from a Chinese couple visiting the country in mid-January 2020. Three months on, by mid-March, the COVID-19 cases in the Philippines had reached its first 100, before it exploded to the present 178,022 cases (as of August 20, 2020). Here, we report a genomic survey of six (6) whole genomes of the SARS-CoV-2 virus collected from COVID-19 patients seen at the Philippine General Hospital, the major referral hospital for COVID-19 cases in Metro Manila at about the time the Philippines had over a hundred cases. Analysis of commonly observed variants did not reveal a clear pattern of the virus evolving towards a more infectious and severe strain. When combined with other available viral sequences from the Philippines and from GISAID, phylogenomic analysis reveal that the sequenced Philippine isolates can be classified into three primary groups based on collection dates and possible infection sources: (1) January samples collected in the early phases of the pandemic that are closely associated with isolates from Wuhan, China; (2) March samples that are mainly linked to the M/V Diamond Princess Cruise Ship outbreak; and (3) June samples that clustered with European isolates, one of which already harbor the globally prevalent D614G mutation which initially circulated in Europe. The presence of community-acquired viral transmission amidst compulsory and strict quarantine protocols, particularly for repatriated Filipino workers, highlights the need for a refinement of the quarantine, testing, and tracing strategies currently being implemented to adapt to the current pandemic situation.

Envisioning the Health Research System in the Philippines by 2040: A perspective inspired by Ambisyon Natin 2040

@#<p style="text-align: justify;"><strong>BACKGROUND AND OBJECTIVE:</strong> This paper aims to describe long-term visions for health research in the Philippines. Ambisyon Natin 2040, an overarching vision for a dynamic country by the year 2040, is its main inspiration as this enables innovation and sustainable development.</p><p style="text-align: justify;"><strong>METHODS:</strong> The health research profile conceptual framework developed by Tugwell et al., (2006) was utilized to structure the articulation of these visions. Review of related literature, reports, and documents and in-depth interviews with key players in health research were conducted.</p><p style="text-align: justify;"><strong>RESULTS:</strong> In view of economic and technological developments in the country, it is expected that in 2040, health research priorities shall be more trans-disciplinary and more advanced. Research on health regulation and ethics will continue to be of importance. A more enabling environment for health research is also envisioned, since majority of research funding is expected to come from government, in addition to more research-friendly laws. More innovative platforms will be utilized to disseminate research results. The increasing international exposure and impact of academic work in the Philippines is also envisaged.</p><p style="text-align: justify;"><strong>CONCLUSION AND RECOMMENDATIONS: </strong>Health research in the Philippines has been benefitted by a lot of gains and advances in the past years. Thus, to create an enabling health research system in the Philippines by 2040, focusing on innovations in health research, increased number of funding sources, and crafting of better policies on health research should be pursued. Sustaining these gains and advancing health research in our country entail collective effort from different stakeholders, both public and private.</p>

The prevalence of CYP2D6 Gene Polymorphisms among Filipinos and their use as biomarkers for lung cancer risk

Objectives@#The highly polymorphic nature of the CYP2D6 gene and its central role in the metabolism of commonly used drugs make it an ideal candidate for pharmacogenetic screening. This study aims to determine the prevalence of CYP2D6 polymorphisms among Filipinos and their association to lung cancer. @*Method@#Forty seven single nucleotide polymorphisms (SNPs) of the CYP2D6 gene were genotyped from DNA samples of 115 cases with lung cancer and age- and sex-matched 115 controls. @*Results@#Results show that 18 out of 47 polymorphisms have significant genotypic variability (>1% for at least 2 genotypes). No variant is associated with lung cancer. However, rs1135840, rs16947 and rs28360521, were found to be highly variable among Filipinos. @*Conclusion@#This study demonstrated that CYP2D6 polymorphisms are present among Filipinos, which, although not found to be associated with lung cancer, can be useful biomarkers for future pharmacogenetic studies. The SNP rs16947 is found to be associated with cancer and timolol-induced bradycardia; the SNP rs1135840, on the other hand, is only shown to be linked with cancer. The genetic variant rs28360521 is known to be associated with low-dose aspirin-induced lower gastrointestinal bleeding.