Prevalence of Plasmodium falciparum molecular markers of antimalarial drug resistance in a residual malaria focus area in Sabah, Malaysia

Chloroquine (CQ) and fansidar (sulphadoxine-pyrimethamine, SP) were widely used for treatment of Plasmodium falciparum for several decades in Malaysia prior to the introduction of Artemisinin-based Combination Therapy (ACT) in 2008. Our previous study in Kalabakan, located in south-east coast of Sabah showed a high prevalence of resistance to CQ and SP, suggesting the use of the treatment may no longer be effective in the area. This study aimed to provide a baseline data of antimalarial drug resistant markers on P. falciparum isolates in Kota Marudu located in the north-east coast of Sabah. Mutations on genes associated with CQ (pfcrt and pfmdr1) and SP (pfdhps and pfdhfr) were assessed by PCR amplification and restriction fragment length polymorphism. Mutations on the kelch13 marker (K13) associated with artemisinin resistance were determined by DNA sequencing technique. The assessment of pfmdr1 copy number variation associated with mefloquine resistant was done by real-time PCR technique. A low prevalence (6.9%) was indicated for both pfcrt K76T and pfmdr1 N86Y mutations. All P. falciparum isolates harboured the pfdhps A437G mutation. Prevalence of pfdhfr gene mutations, S108N and I164L, were 100% and 10.3%, respectively. Combining the different resistant markers, only two isolates were conferred to have CQ and SP treatment failure markers as they contained mutant alleles of pfcrt and pfmdr1 together with quintuple pfdhps/pfdhfr mutation (combination of pfdhps A437G+A581G and pfdhfr C59R+S108N+I164L). All P. falciparum isolates carried single copy number of pfmdr1 and wild type K13 marker. This study has demonstrated a low prevalence of CQ and SP resistance alleles in the study area. Continuous monitoring of antimalarial drug efficacy is warranted and the findings provide information for policy makers in ensuring a proper malaria control

Permissibility of prenatal diagnosis and abortion for fetuses with severe genetic disorder: type 1 spinal muscular atrophy

Abortion has been largely avoided in Muslim communities. However, Islamic jurists have established rigorous parameters enabling abortion of fetuses with severe congenital abnormalities. This decision-making process has been hindered by an inability to predict the severity of such prenatally-diagnosed conditions, especially in genetic disorders with clinical heterogeneity, such as spinal muscular atrophy (SMA). Heterogeneous phenotypes of SMA range from extremely severe type 1 to very mild type 4. Advances in molecular genetics have made it possible to perform prenatal diagnosis and to predict the types of SMA with its potential subsequent severity. Such techniques will make it possible for clinicians working in predominantly Muslim countries to counsel their patients accurately and in harmony with their religious beliefs. In this paper, we discuss and postulate that with our current knowledge of determining SMA types and severity with great accuracy, abortion is legally applicable for type 1 SMA