Screening of 22q11.2DS Using Multiplex Ligation-Dependent Probe Amplification as an Alternative Diagnostic Method.

BACKGROUND: The 22q11.2 deletion syndrome (22q11.2DS) is the most common form of deletion disorder in humans. Low copy repeats flanking the 22q11.2 region confers a substrate for nonallelic homologous recombination (NAHR) events leading to rearrangements which have been reported to be associated with highly variable and expansive phenotypes. The 22q11.2DS is reported as the most common genetic cause of congenital heart defects (CHDs). METHODS: A total of 42 patients with congenital heart defects, as confirmed by echocardiography, were recruited. Genetic molecular analysis using a fluorescence in situ hybridization (FISH) technique was conducted as part of routine 22q11.2DS screening, followed by multiplex ligation-dependent probe amplification (MLPA), which serves as a confirmatory test. RESULTS: Two of the 42 CHD cases (4.76%) indicated the presence of 22q11.2DS, and interestingly, both cases have conotruncal heart defects. In terms of concordance of techniques used, MLPA is superior since it can detect deletions within the 22q11.2 locus and outside of the typically deleted region (TDR) as well as duplications. CONCLUSION: The incidence of 22q11.2DS among patients with CHD in the east coast of Malaysia is 0.047. MLPA is a scalable and affordable alternative molecular diagnostic method in the screening of 22q11.2DS and can be routinely applied for the diagnosis of deletion syndromes.

Mutations in the tail domain of MYH3 contributes to atrial septal defect.

Atrial septal defect (ASD) is one of the most common congenital heart defects diagnosed in children. Sarcomeric genes has been attributed to ASD and knockdown of MYH3 functionally homologues gene in chick models indicated abnormal atrial septal development. Here, we report for the first time, a case-control study investigating the role of MYH3 among non-syndromic ASD patients in contributing to septal development. Four amplicons which will amplifies the 40 kb MYH3 were designed and amplified using long range-PCR. The amplicons were then sequenced using indexed paired-end libraries on the MiSeq platform. The STREGA guidelines were applied for planning and reporting. The non-synonymous c. 3574G>A (p.Ala1192Thr) [p = 0.001, OR = 2.30 (1.36-3.87)] located within the tail domain indicated a highly conserved protein region. The mutant model of c. 3574G>A (p.Ala1192Thr) showed high root mean square deviation (RMSD) values compared to the wild model. To our knowledge, this is the first study to provide compelling evidence on the pathogenesis of MYH3 variants towards ASD hence, suggesting the crucial role of non-synonymous variants in the tail domain of MYH3 towards atrial septal development. It is hoped that this gene can be used as panel for diagnosis of ASD in future.

A Novel Multiplex PCR-RFLP Method for Simultaneous Genotyping of CYP3A4*4 A>G, CYP3A4*18B G>A and CYP3A4*22 C>T.

BACKGROUND: Cytochrome P450 3A enzymes exhibit a variety of physiological roles and have been reported to be the most predominant enzymes involved in drugs metabolism. Single nucleotide polymorphisms (SNPs) in the genes that code for these enzymes may result in functional changes that affect enzyme activity. CYP3A4 is an important enzyme in the metabolism of many important drugs used in the treatment of breast cancer. METHODS: A total of 94 post-menopausal breast cancer patients were recruited for the study and their DNA was isolated for polymerase chain reaction (PCR). The primers were designed using Primer3 software with primer specificities checked via the Basic Local Alignment Tool (BLAST) database. The primer specificity, functionality and annealing temperature were first investigated using uniplex PCR protocols, followed by a single multiplex polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. The digested amplification fragments were analysed by gel electrophoresis and subsequently validated by sequencing. RESULTS: A multiplex PCR-RFLP method was successfully developed for simultaneous detection of CYP3A4*4, CYP3A4*18B and CYP3A4*22 in a population of post-menopausal breast cancer patients. CONCLUSION: The technique is simple, cost-effective, time-saving and can be routinely applied in the identification of SNPs and determination of allelic and genotypic frequencies of CYP3A4*4, CYP3A4*18B and CYP3A4*22.

Screening of SMAD7 in Malay patients with ventricular septal defect.

Ventricular septal defect (VSD) is the most common form of cardiac malformations accounting approximately 20% of all congenital heart defects. SMAD7 is an inhibitory protein that antagonizes the signalling of TGF-ß family member and has been found in the development and function of mouse heart models. This study aims to screen and identify the polymorphisms of SMAD7 exonic regions in Malay population with VSD. Peripheral blood samples were collected and extracted from 30 clinically diagnosed VSD patients. PCR amplification was performed using 12 sets of designed primers encompassing seven exons of SMAD7. Re-sequencing was conducted to characterize the polymorphisms of SMAD7. Observed polymorphisms were then genotyped in 30 healthy individuals using both re-sequencing and allele-specific PCR techniques. A total of 10 variants were identified in the patient population located in the upstream (rs7236774), exonic (rs368427729, rs145686330, rs3764482, rs3809922, rs780863704 and rs3809923), intronic (rs3736242) and 3'UTR regions (rs375444823 and rs16950113). No significant difference of genotype and allele frequency was observed among these SNPs. Two synonymous variants (rs3809922 and rs3809923) were found in complete linkage disequilibrium (r2=1.0) with each other indicate a strong correlation of these SNPs. The identification of these SNPs provides a new perspective of the VSD causation.

Validity and reliability of the Malay version of the Structured Migraine Interview (SMI) Questionnaire.

BACKGROUND: The Structured Migraine Interview (SMI) is a valid and reliable instrument for migraine diagnosis. However, a Malay version of the SMI is not available to be applied to the local Malaysian population. This study was designed to access the validity and reliability of a new Malay version of the SMI questionnaire. METHODS: Patients with headache attending the Neurology Clinic, Hospital Universiti Sains Malaysia, Kelantan, Malaysia, were screened against the inclusion/exclusion criteria before recruitment. A standard translation procedure was used to translate and adapt the questionnaire into the Malay language. The translated version was tested for face, content and construct validities. Subsequently, validity and reliability studies were conducted (1(st) compilation), followed by retesting seven days later (2(nd) compilation). RESULTS: A total of 157 patients between 15 and 60 years of age were enrolled in this study. The kappa value was 0.70 (p < 0.001) with high sensitivity (0.97) and specificity (0.63). The misclassification rate was 0.15, with a positive predictive value of 0.82 and a negative predictive value of 0.92. The positive likelihood ratio was 2.62, while the negative likelihood ratio was 0.05. The Cronbach's alpha was 0.93 (1(st) compilation) and 0.90 (2(nd) compilation), respectively. The Spearman's correlation coefficient ranged from 0.86 (Question 4) to 0.95 (Question 1). The overall concordance for item 1 was very high (97%), followed by item 4 (83%), item 2 (71%) and finally item 3 (64%). CONCLUSION: The Malay version of the SMI questionnaire is comparable to the English version in terms of validity and reliability. It was highly reliable with good internal consistency and can be used for the diagnosis of migraine in clinical settings in Malaysia.

Quality of life and migraine disability among female migraine patients in a tertiary hospital in Malaysia.

BACKGROUND: Disability caused by migraine may be one of the main causes of burden contributing to poor quality of life (QOL) among migraine patients. Thus, this study aimed to measure QOL among migraine sufferers in comparison with healthy controls. METHODS: Female diagnosed migraine patients (n= 100) and healthy controls (n=100) completed the Malay version of the World Health Organization QOL Brief (WHOQOL-BREF) questionnaire. Only migraine patients completed the Malay version of the Migraine Disability Assessment questionnaire. RESULTS: Females with migraines had significantly lower total WHOQOL-BREF scores (84.3) than did healthy controls (91.9, P<0.001). Similarly, physical health (23.4 versus 27.7, P<0.001) and psychological health scores (21.7 versus 23.2, P< 0.001) were significantly lower than those for healthy controls. Seventy-three percent of patients experienced severe disability, with significantly higher number of days with headaches (13.8 days/3 months, P< 0.001) and pain scores (7.4, P< 0.013). Furthermore, migraine patients with lower total QOL scores had 1.2 times higher odds of having disability than patients with higher total QOL scores. CONCLUSIONS: The present study showed that migraine sufferers experienced significantly lower QOL than the control group from a similar population. Disability was severe and frequent and was associated with lower QOL among the migraine patients.

Validity and reliability of the Bahasa Melayu version of the Migraine Disability Assessment questionnaire.

BACKGROUND: The study was designed to determine the validity and reliability of the Bahasa Melayu version (MIDAS-M) of the Migraine Disability Assessment (MIDAS) questionnaire. METHODS: Patients having migraine for more than six months attending the Neurology Clinic, Hospital Universiti Sains Malaysia, Kubang Kerian, Kelantan, Malaysia, were recruited. Standard forward and back translation procedures were used to translate and adapt the MIDAS questionnaire to produce the Bahasa Melayu version. The translated Malay version was tested for face and content validity. Validity and reliability testing were further conducted with 100 migraine patients (1st administration) followed by a retesting session 21 days later (2nd administration). RESULTS: A total of 100 patients between 15 and 60 years of age were recruited. The majority of the patients were single (66%) and students (46%). Cronbach's alpha values were 0.84 (1st administration) and 0.80 (2nd administration). The test-retest reliability for the total MIDAS score was 0.73, indicating that the MIDAS-M questionnaire is stable; for the five disability questions, the test-retest values ranged from 0.77 to 0.87. CONCLUSION: The MIDAS-M questionnaire is comparable with the original English version in terms of validity and reliability and may be used for the assessment of migraine in clinical settings.

Do folate, vitamins B6 and B12 play a role in the pathogenesis of migraine? The role of pharmacoepigenomics.

Migraine is a neurovascular disease that has classically been attributed to multifactorial aetiologies, with genetic components and environmental interactions considered the main influence. Genes such as flavoenzyme 5, 10- methylenetetrahydrofolate reductase (MTHFR), especially the C677T variant, have been associated with elevated plasma homocysteine levels. This elevation in homocysteine results in an array of metabolic disorders and increased risk of complex diseases, including migraine. Catalysation of homocysteine requires the presence of vitamins B6, B12 and folate. Deficiencies in these cofactor vitamins result in hypomethylation, which triggers migraine. Because migraine predominantly affects females, it is hypothesised that fluctuating oestrogen levels, which are governed by oestrogen receptor 1 polymorphisms, are important. Another important factor is homocysteine, the production of which is dependent upon MTHFR and B vitamins. Gene expression is modulated through epigenetic mechanisms, which involve methionine. Additionally, folate plays a major role in DNA synthesis. We propose that vitamin B intake, coupled with MTHFR and oestrogen receptor 1 polymorphisms, causes differential DNA methylation and gene expression that may contribute to the occurrence of migraine.