The fat mass and obesity-associated FTO rs9939609 polymorphism is associated with elevated homocysteine levels in patients with multiple sclerosis screened for vascular risk factors

Association Between Maternal Factors and Risk of Congenital Heart Disease in Offspring: A Systematic Review and Meta-Analysis

INTRODUCTION

This study aimed to summarize the evidence describing the relationship between maternal factors during gestation and risk of congenital heart disease (CHD) in offspring.

METHODS

PubMed, EMBASE, and the Cochrane Library were searched for potentially relevant reports from inception to May 2021. Pooled odds ratios (ORs) with 95% confidence intervals (CIs) calculated by the random-effects model were used to evaluate the association between maternal factors and CHD risk.

RESULTS

There was a significant association between CHD risk and obesity in pregnancy (OR 1.29, 95% CI 1.22-1.37; P < 0.001), smoking in pregnancy (OR 1.16, 95% CI 1.07-1.25; P < 0.001), maternal diabetes (OR 2.65, 95% CI 2.20-3.19; P < 0.001), and exposure of pregnant women to organic solvents (OR 1.82, 95% CI 1.23-2.70; P = 0.003). No correlations were revealed between CHD susceptibility and advanced maternal age (OR 1.04, 95% CI 0.96-1.12; P = 0.328), underweight (OR 1.02, 95% CI 0.96-1.08; P = 0.519), alcohol intake in pregnancy (OR 1.08, 95% CI 0.95-1.22; P = 0.251), coffee intake (OR 1.18, 95% CI 0.97-1.44; P = 0.105), and exposure to irradiation (OR 1.80, 95% CI 0.85-3.80; P = 0.125).

DISCUSSION

Maternal factors including maternal obesity, smoking in pregnancy, maternal diabetes and exposure to organic solvents might predispose the offspring to CHD risk.

m6A Methylation in Cardiovascular Diseases: From Mechanisms to Therapeutic Potential

Cardiovascular disease (CVD) is a leading cause of morbidity and mortality worldwide. Recent studies have shown that n6-methyladenosine (m6A) plays a major role in cardiovascular homeostasis and pathophysiology. These studies have confirmed that m6A methylation affects the pathophysiology of cardiovascular diseases by regulating cellular processes such as differentiation, proliferation, inflammation, autophagy, and apoptosis. Moreover, plenty of research has confirmed that m6A modification can delay the progression of CVD via the post-transcriptional regulation of RNA. However, there are few available summaries of m6A modification regarding CVD. In this review, we highlight advances in CVD-specific research concerning m6A modification, summarize the mechanisms underlying the involvement of m6A modification during the development of CVD, and discuss the potential of m6A modification as a therapeutic target of CVD.

Pathology-supported genetic testing as a method for disability prevention in multiple sclerosis (MS). Part I. Targeting a metabolic model rather than autoimmunity

In this Review (Part I), we investigate the scientific evidence that multiple sclerosis (MS) is caused by the death of oligodendrocytes, the cells that synthesize myelin, due to a lack of biochemical and nutritional factors involved in mitochondrial energy production in these cells. In MS, damage to the myelin sheaths surrounding nerve axons causes disruption of signal transmission from the brain to peripheral organs, which may lead to disability. However, the extent of disability is not deterred by the use of MS medication, which is based on the autoimmune hypothesis of MS. Rather, disability is associated with the loss of brain volume, which is related to the loss of grey and white matter. A pathology-supported genetic testing (PSGT) method, developed for personalized assessment and treatment to prevent brain volume loss and disability progression in MS is discussed. This involves identification of MS-related pathogenic pathways underpinned by genetic variation and lifestyle risk factors that may converge into biochemical abnormalities associated with adverse expanded disability status scale (EDSS) outcomes and magnetic resonance imaging (MRI) findings during patient follow-up. A Metabolic Model is presented which hypothesizes that disability may be prevented or reversed when oligodendrocytes are protected by nutritional reserve. Evidence for the validity of the Metabolic Model may be evaluated in consecutive test cases following the PSGT method. In Part II of this Review, two cases are presented that describe the PSGT procedures and the clinical outcomes of these individuals diagnosed with MS.

Pathology-supported genetic testing as a method for disability prevention in multiple sclerosis (MS). Part II. Insights from two MS cases

In Part I of this Review we evaluated the scientific evidence for a Metabolic Model of multiple sclerosis (MS). Part II outlines the implementation of an adaptive pathology-supported genetic testing (PSGT) algorithm aimed at preventing/reversing disability in two illustrative MS cases, starting with a questionnaire-based risk assessment, including family history and lifestyle factors. Measurement of iron, vitamin B12, vitamin D, cholesterol and homocysteine levels identified biochemical deficits in both cases. Case 1, after following the PSGT program for 15 years, had an expanded disability status scale (EDSS) of 2.0 (no neurological sequelae) together with preserved brain volume on magnetic resonance imaging (MRI). A novel form of iron deficiency was identified in Case 1, as biochemical testing at each hospital submission due to MS symptoms showed low serum iron, ferritin and transferrin saturation, while hematological status and erythrocyte sedimentation rate measurement of systemic inflammation remained normal. Case 2 was unable to walk unaided until her EDSS improved from 6.5 to 4.0 over 12 months after implementation of the PSGT program, with amelioration of her suboptimal biochemical markers and changes to her diet and lifestyle, allowing her to regain independence. Genotype-phenotype correlation using a pathway panel of functional single nucleotide variants (SNVs) to facilitate clinical interpretation of whole exome sequencing (WES), elucidated the underlying metabolic pathways related to the biochemical deficits. A cure for MS will remain an elusive goal if separated from nutritional support required for production and maintenance of myelin, which can only be achieved by a lifelong investment in wellness.

RNA Modification by m6A Methylation in Cardiovascular Disease

Cardiovascular disease is currently the leading cause of death worldwide, and its underlying regulatory mechanisms remain largely unknown. N⁶-Methyladenosine (m⁶A) RNA methylation is an epigenetic modification involved in the splicing, nuclear export, translational regulation, and degradation of RNA. After the initial identification of m⁶A RNA methylation in 1974, the rise of next-generation sequencing technology to detect m⁶A throughout the transcriptome led to its renewed recognition in 2012. Since that time, m⁶A methylation has been extensively studied, and its functions, mechanisms, and effectors (e.g., METTL3, FTO, METTL14, WTAP, ALKBH5, and YTHDFs) in various diseases, including cardiovascular diseases, have rapidly been investigated. In this review, we first examine and summarize the molecular and cellular functions of m⁶A methylation and its readers, writers, and erasers in the cardiovascular system. Finally, we discuss future directions for m⁶A methylation research and the potential for therapeutic targeting of m⁶A modification in cardiovascular disease.

Hyperhomocysteinemia and Endothelial Dysfunction in Multiple Sclerosis

Endothelial dysfunction is recognized as one of the leading factors in the pathogenesis of diseases of the central nervous system of various etiologies. Numerous studies have shown the role of hyperhomocysteinemia in the development of endothelial dysfunction and the prothrombogenic state. The most important condition in the development of multiple sclerosis (MS) is a dysregulation of the blood-brain barrier (BBB) and transendothelial leukocyte migration. It has been proven that homocysteine also contributes to the damage of neurons by the mechanism of excitotoxicity and the induction of the apoptosis of neurons. These processes can be one of the factors of neurodegenerative brain damage, which plays a leading role in the progression of MS. This review describes the pleiotropic effect of homocysteine on these processes and its role in MS pathogenesis.

Bioinformatics approaches for deciphering the epitranscriptome: Recent progress and emerging topics

Post-transcriptional RNA modification occurs on all types of RNA and plays a vital role in regulating every aspect of RNA function. Thanks to the development of high-throughput sequencing technologies, transcriptome-wide profiling of RNA modifications has been made possible. With the accumulation of a large number of high-throughput datasets, bioinformatics approaches have become increasing critical for unraveling the epitranscriptome. We review here the recent progress in bioinformatics approaches for deciphering the epitranscriptomes, including epitranscriptome data analysis techniques, RNA modification databases, disease-association inference, general functional annotation, and studies on RNA modification site prediction. We also discuss the limitations of existing approaches and offer some future perspectives.

Serum levels of Homocysteine, Vitamin B12 and Folate in Patients with Multiple Sclerosis: an Updated Meta-Analysis

Background: Multiple sclerosis (MS) is a demyelinating and disabling inflammatory disease of the central nervous system. MS is triggered by complex environmental factors which mostly affect genetically the susceptible young people. Emerging data has suggested that changes of homocysteine (Hcy), Vitamin B12 and folate serum levels may be associated with MS. However, previous findings are not always consistent. Methods: In this study, we aimed to investigate the relationships between MS and Hcy, Vitamin B12 and folate with updated available data (until September, 2019). The diagnosis of MS was performed based on international criteria for the diagnosis of MS, including magnetic resonance imaging and cerebrospinal fluid tests. We searched the databases including PubMed, EMBASE, Cochrane Library and ScienceDirect. After data collection, separate analyses based on random-effect models were used to test for relationships between MS and Hcy, Vitamin B12 or folate blood levels. The effective sizes were estimated by the combined standardized mean difference (SMD) and associated 95% confidence interval (CI). Results: Based on the inclusion criteria, a total of 21 original studies with 1738 MS patients and 1424 controls were included in this study. There were 17 studies for measuring Hcy, 16 studies for measuring Vitamin B12 and 13 studies for measuring folate in patients with MS, respectively. Specifically, patients with MS had higher serum levels of Hcy (SMD: 0.64; 95% CI:0.33, 0.95; P <0.0001) compared with control groups. There were no significant differences of SMD for Vitamin B12 (SMD: -0.08; 95% CI: -0.35, 0.20; P=0.58) or folate (SMD: 0.07; 95% CI: -0.14, 0.28; P=0.52) between MS and controls. Subgroup analysis demonstrated that there was statistically significant difference for Hcy between relapsing-remitting MS (RRMS) patients and controls with a SMD of 0.67 (95% CI: 0.21, 1.13; P=0.004). However, no significant difference of Hcy serum levels between secondary progressive MS patients or primary progressive MS patients and controls was noted in this study. In addition, there was no significant difference of Hcy levels in females (SMD: 0.22; 95% CI: -0.16, 0.60; P=0.25) or males (SMD: 0.56; 95% CI: -0.13, 1.26; P=0.11) between MS patients and controls. Conclusions: Higher serum levels of Hcy were noted in patients with MS when compared with control groups. And the difference was especially significant between RRMS patients and controls. Hcy may play an important role in the pathogenesis of MS. Functional studies are required to assess the effects of Hcy on patients with MS at the molecular level.

The FTO gene polymorphism rs9939609 is associated with obesity and disability in multiple sclerosis patients

Obesity is a well-known risk factor for multiple diseases including multiple sclerosis (MS). Polymorphisms in the fat-mass obesity (FTO) gene have been consistently found to be associated with obesity, and recently found to increase the risk of developing MS. We therefore assessed the common FTO gene polymorphism (rs9939609) in relation to obesity, risk of developing MS and its disability in a cohort of MS patients. A cohort of 200 MS patients (135 females and 65 males) were genotyped for the FTO rs9939609 polymorphism. Using both logistic and linear regression we assessed the relationship between the variant and the selected phenotypes under both an additive and recessive genetic models. The A-allele was found to be associated with being overweight/obese in MS patients (OR = 2.48 (95% CI 1.17–5.29); p = 0.01). In addition, The A-allele was also found to be associated with increased MS disability (β = 0.48 (95% CI 0.03–0.92); p = 0.03). However, no association was found with risk of developing MS (p > 0.05). Moreover, our association with obesity is consistent with previous reports, whereas the association with disability is novel and warrants further investigation on the role of FTO in disease progression.

Identification of an iron-responsive subtype in two children diagnosed with relapsing-remitting multiple sclerosis using whole exome sequencing

BACKGROUND

Multiple sclerosis is a disorder related to demyelination of axons. Iron is an essential cofactor in myelin synthesis. Previously, we described two children (males of mixed ancestry) with relapsing-remitting multiple sclerosis (RRMS) where long-term remission was achieved by regular iron supplementation. A genetic defect in iron metabolism was postulated, suggesting that more advanced genetic studies could shed new light on disease pathophysiology related to iron.

METHODS

Whole exome sequencing (WES) was performed to identify causal pathways. Blood tests were performed over a 10 year period to monitor the long-term effect of a supplementation regimen. Clinical wellbeing was assessed quarterly by a pediatric neurologist and regular feedback was obtained from the schoolteachers.

RESULTS

WES revealed gene variants involved in iron absorption and transport, in the transmembrane protease, serine 6 (TMPRSS6) and transferrin (TF) genes; multiple genetic variants in CUBN, which encodes cubilin (a receptor involved in the absorption of vitamin B12 as well as the reabsorption of transferrin-bound iron and vitamin D in the kidneys); SLC25A37 (involved in iron transport into mitochondria) and CD163 (a scavenger receptor involved in hemorrhage resolution). Variants were also found in COQ3, involved with synthesis of Coenzyme Q10 in mitochondria. Neither of the children had the HLA-DRB1*1501 allele associated with increased genetic risk for MS, suggesting that the genetic contribution of iron-related genetic variants may be instrumental in childhood MS. In both children the RRMS has remained stable without activity over the last 10 years since initiation of nutritional supplementation and maintenance of normal iron levels, confirming the role of iron deficiency in disease pathogenesis in these patients.

CONCLUSION

Our findings highlight the potential value of WES to identify heritable risk factors that could affect the reabsorption of transferrin-bound iron in the kidneys causing sustained iron loss, together with inhibition of vitamin B12 absorption and vitamin D reabsorption (CUBN) and iron transport into mitochondria (SLC25A37) as the sole site of heme synthesis. This supports a model for RRMS in children with an apparent iron-deficient biochemical subtype of MS, with oligodendrocyte cell death and impaired myelination possibly caused by deficits of energy- and antioxidant capacity in mitochondria.

Emerging function of N6-methyladenosine in cancer

N6-methyladenosine (m6A) modification in RNA has been implicated in diverse biological processes including the maintenance of embryonic stem cells, early development and diseases. Although the m6A modification was discovered several decades ago, its biological function remained unclear. The recent discovery of enzymes responsible for 'writing' or 'erasing' the modification and single-nucleotide resolution mapping by next-generation sequencing technology have revealed its function in biological processes. Its enrichment pattern is conserved in mammalian transcriptomes, and the level of m6A is tightly regulated by methyltransferases (writers), demethylases (erasers) and binding proteins (readers). Furthermore, accumulating evidence suggests that the aberrant regulation of m6A turnover is associated with multiple types of cancer including acute myeloid leukemia, breast cancer, glioblastoma, lung cancer and liver cancer. Studies have demonstrated that factors involved in m6A metabolism serve either oncogenic or tumor-suppressor roles in different contexts. The previous studies of the role of m6A in cancer biology are discussed in the present review.

Dietary approaches to treat MS-related fatigue: comparing the modified Paleolithic (Wahls Elimination) and low saturated fat (Swank) diets on perceived fatigue in persons with relapsing-remitting multiple sclerosis: study protocol for a randomized controlled trial

BACKGROUND

Fatigue is one of the most disabling symptoms of multiple sclerosis (MS) and contributes to diminishing quality of life. Although currently available interventions have had limited success in relieving MS-related fatigue, clinically significant reductions in perceived fatigue severity have been reported in a multimodal intervention pilot study that included a Paleolithic diet in addition to stress reduction, exercise, and electrical muscle stimulation. An optimal dietary approach to reducing MS-related fatigue has not been identified. To establish the specific effects of diet on MS symptoms, this study focuses on diet only instead of the previously tested multimodal intervention by comparing the effectiveness of two dietary patterns for the treatment of MS-related fatigue. The purpose of this study is to determine the impact of a modified Paleolithic and low saturated fat diet on perceived fatigue (primary outcome), cognitive and motor symptoms, and quality of life in persons with relapsing-remitting multiple sclerosis (RRMS).

METHODS/DESIGN

This 36-week randomized clinical trial consists of three 12-week periods during which assessments of perceived fatigue, quality of life, motor and cognitive function, physical activity and sleep, diet quality, and social support for eating will be collected. The three 12-week periods will consist of the following: 1.

OBSERVATION

Participants continue eating their usual diet. 2.

INTERVENTION

Participants will be randomized to a modified Paleolithic or low saturated fat diet for the intervention period. Participants will receive support from a registered dietitian (RD) through in-person coaching, telephone calls, and emails. 3.

FOLLOW-UP

Participants will continue the study diet for an additional 12 weeks with minimal RD support to assess the ability of the participants to sustain the study diet on their own.

DISCUSSION

Because fatigue is one of the most common and disabling symptoms of MS, effective management and reduction of MS-related fatigue has the potential to increase quality of life in this population. The results of this study will add to the evidence base for providing dietary recommendations to treat MS-related fatigue and other symptoms associated with this disease.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT02914964 . Registered on 24 August 2016.

Fractional anisotropy of white matter, disability and blood iron parameters in multiple sclerosis

Multiple sclerosis (MS) is a disorder related to myelin damage, which can be investigated by neuroimaging techniques such as fractional anisotropy (FA), a measure of microstructural white matter properties. The objectives of this study were to investigate (1) the relationship between FA and disability using an extremes of outcome approach, and (2) whether blood iron parameters were associated with FA and/or disability. Patients diagnosed with MS (n = 107; 14 males and 93 females) had iron parameter tests and disability determinations using the Expanded Disability Status Scale (EDSS). FA was recorded in 48 white matter tracts in 11 of the female patients with MS and 12 female controls.

RESULTS

In patients with high disability scores the mean FA was significantly lower (0.34 ± 0.067) than in the control group (0.45 ± 0.036; p = 0.04), while patients with low disability had mean FA values (0.44 ± 0.014) similar to controls (p = 0.5). Positive associations were found between FA and the iron parameters serum iron, ferritin and percentage transferrin saturation (%Tfsat) in all the white matter tracts. For % Tfsat, the associations were highly significant in 14 tracts (p < 0.01; r-values 0.74-0.84) and p < 0.001 (r = 0.83) in the superior fronto occipital fasciculus (LH). In the whole patient group a trend was found towards an inverse association between the EDSS and the %Tfsat (r = -0.26, p = 0.05) after excluding male gender and smoking as confounders, suggesting reduced disability in the presence of higher blood iron parameters. Additionally, significant inverse associations between disease duration and haemoglobin (p = 0.04) as well as %Tfsat (p = 0.02) suggested that patients with MS may experience a decrease in blood iron concentrations over time.

Complex Relationship between Obesity and the Fat Mass and Obesity Locus

In the 21st century, obesity has become a serious problem because of increasing obese patients and numerous metabolic complications. The primary reasons for this situation are environmental and genetic factors. In 2007, FTO (fat mass and obesity associated) was the first gene identified through a genome-wide association study (GWAS) associated with obesity in humans. Subsequently, a cluster of single nucleotide polymorphisms (SNPs) in the first intron of the FTO gene was discovered to be associated with BMI and body composition. Various studies have explored the mechanistic basis behind this association. Thus, emerging evidence showed that FTO plays a key role regulating adipose tissue development and functions in body size and composition. Recent prevalent research topic concentrated in the three neighboring genes of FTO: RPGRIP1L, IRX3 and IRX5, as having a functional link between obesity-associated common variants within FTO and the observed human phenotypes. The purpose of this review is to present a comprehensive picture of the impact of FTO on obesity susceptibility and to illuminate these new studies of FTO function in adipose tissue.

Folate Metabolism Regulates Oligodendrocyte Survival and Differentiation by Modulating AMPKα Activity

Folate, an essential micronutrient, is a critical cofactor in one-carbon metabolism for many cellular pathways including DNA synthesis, metabolism and maintenance. Folate deficiency has been associated with an increased risk of neurological disease, cancer and cognitive dysfunction. Dihydrofolate reductase (DHFR) is a key enzyme to regulate folate metabolism, however folate/DHFR activity in oligodendrocyte development has not been fully understood. Here we show that folate enhances oligodendrocyte maturation both in vitro and in vivo, which is accompanied with upregulation of oligodendrocyte-specific DHFR expression. On the other hand, pharmacological inhibition of DHFR by methotrexate (MTX) causes severe defects in oligodendrocyte survival and differentiation, which could be reversed by folate intake. We further demonstrate that folate activates a metabolic regulator AMPKα to promote oligodendrocyte survival and differentiation. Moreover, activation of AMPKα partially rescues oligodendrocyte defects caused by DHFR-inhibition both in vitro and in vivo. Taken together, these findings identify a previously uncharacterized role of folate/DHFR/AMPKα axis in regulating oligodendrocyte survival and myelination during CNS development.

Causal Effect of Genetic Variants Associated With Body Mass Index on Multiple Sclerosis Susceptibility

Multiple sclerosis (MS) is an autoimmune disease with both genetic and environmental risk factors. Recent studies indicate that childhood and adolescent obesity double the risk of MS, but this association may reflect unmeasured confounders rather than causal effects of obesity. We used separate-sample Mendelian randomization to estimate the causal effect of body mass index (BMI) on susceptibility to MS. Using data from non-Hispanic white members of the Kaiser Permanente Medical Care Plan of Northern California (KPNC) (2006-2014; 1,104 cases of MS and 10,536 controls) and a replication data set from Sweden (the Epidemiological Investigation of MS (EIMS) and the Genes and Environment in MS (GEMS) studies, 2005-2013; 5,133 MS cases and 4,718 controls), we constructed a weighted genetic risk score using 97 variants previously established to predict BMI. Results were adjusted for birth year, sex, education, smoking status, ancestry, and genetic predictors of MS. Estimates in KPNC and Swedish data sets suggested that higher genetically induced BMI predicted greater susceptibility to MS (odds ratio = 1.13, 95% confidence interval: 1.04, 1.22 for the KPNC sample; odds ratio = 1.09, 95% confidence interval: 1.03, 1.15 for the Swedish sample). Although the mechanism remains unclear, to our knowledge, these findings support a causal effect of increased BMI on susceptibility to MS for the first time, and they suggest a role for inflammatory pathways that characterize both obesity and the MS disease process.

Maternal and neonatal FTO rs9939609 polymorphism affect insulin sensitivity markers and lipoprotein profile at birth in appropriate-for-gestational-age term neonates

The influence of maternal fat mass and obesity (FTO) gene polymorphism on neonatal insulin sensitivity/resistance biomarkers and lipoprotein profile has not been tested. The study aimed to assess the association between the FTO rs9939609 polymorphism in mother-neonate couples and neonatal anthropometrical measurements, insulin sensitivity/resistance, and lipid and lipoprotein concentrations at birth. Fifty-three term, appropriate-for-gestational-age, Caucasian newborns together with their respective mothers participated in a cross-sectional study. Sixty-six percent of mothers and neonates carried the A allele (being AA or AT). TT mothers gained less weight during pregnancy, but non-significant maternal gene influence was found for neonatal bodyweight, body mass index, or ponderal index. Neonates from AA + AT mothers showed lower glucose, insulin, and homeostatic model assessment insulin resistance (HOMA-IR) but higher homeostatic model assessment insulin sensitivity (HOMA-IS) and homocysteine than neonates whose mothers were TT. AA + AT neonates had higher insulin and HOMA-IR than TT. The genotype neonatal × maternal association was tested in the following four groups of neonates: TT neonates × TT mothers (nTT × mTT), TT neonates × AA + AT mothers (nTT × mAA + AT), AA + AT neonates × TT mothers (nAA + AT × mTT), and AA + AT neonates × AA + AT mothers (nAA + AT × mAA + AT). Non-significant interactions between neonatal and maternal alleles were found for any parameter tested. However, maternal alleles affected significantly glucose, insulin, HOMA-IR, and homocysteine while neonatal alleles the arylesterase activity. Most significant differences were found between nATT + AA × mTT and nATT + AA × mAA + AT. Glycemia, insulinemia, and HOMA-IR were lower, while the Mediterranean diet adherence (MDA) was higher in the mAA + AT vs. mTT whose children were AA + AT. This dietary fact seems to counterbalance the potential negative effect on glucose homeostasis of the obesogenic A allele in neonates.

Apolipoprotein E genotyping and questionnaire-based assessment of lifestyle risk factors in dyslipidemic patients with a family history of Alzheimer's disease: test development for clinical application

The cholesterol-raising properties of the apolipoprotein E (APOE) epsilon-4 (ε-4) allele has been validated in the South African population. Mounting evidence supports the added value of APOE genotyping for the evaluation of cardiovascular risk in dyslipidemic patients beyond its established role in the diagnosis of late-onset Alzheimer's disease (AD). The aim of this study was to determine the potential benefits of combining AD family history with questionnaire-based lifestyle assessment to facilitate the clinical interpretation of APOE genotyping results. A total of 580 unrelated South African individuals prospectively enrolled in a chronic disease screening program incorporating a genetic component (2010-2015) was selected for inclusion in this study based on the presence (75) or absence (505) of AD family history. Biochemical assessment of their lipid profiles was performed according to standard laboratory protocols. All study participants were genotyped for the APOE ε-2/ε-3/ε-4 alleles using allele-specific TaqMan real-time polymerase chain reaction technology. In patients without a family history of AD, APOE genotype modified the relationship between alcohol intake and body mass index (p = 0.026), with a significant positive correlation noted between these parameters being limited to ε-4 allele carriers. APOE genotype also modified the association between alcohol intake and total serum cholesterol in patients with a positive family history of AD (p = 0.026). We demonstrated the benefits of a questionnaire-based approach for assessment of lifestyle risk factors to facilitate clinical interpretation of APOE genotyping results for targeted intervention in a genetic subgroup of dyslipidemic patients at increased risk for AD.

Multiple sclerosis-like diagnosis as a complication of previously treated malaria in an iron and vitamin D deficient Nigerian patient

In contrast to malaria, multiple sclerosis (MS) is infrequently found in Black Africans. We describe a 29 year old Nigerian female who developed an MS-like condition with symptoms similar to relapsing-remitting MS following malaria infection, leading to a diagnosis of MS. However, absence of hyperintense lesions in the brain and spinal cord presented a conundrum since not all the diagnostic criteria for MS were met. Pathology supported genetic testing (PSGT) was applied to combine family and personal medical history, lifestyle factors, and biochemical test results for interpretation of genetic findings. This approach provides a means of identifying risk factors for different subtypes of demyelinating disease. The patient was subsequently treated according to an individualised intervention program including nutritional supplementation as well as a change in diet and lifestyle. Deficiencies of vitamin B12, iron and vitamin D were addressed. Genetic analysis revealed absence of the HLA DRB1*1501 allele, considered to be the most prominent genetic risk factor for MS. Extended mutation analysis identified variations in three genes in the folate-vitamin B12 metabolic pathway, which could have increased the patient's sensitivity to the antifolate drugs used to treat the malaria. A glutathione-S-transferase GSTM1 null allele, previously associated with neurological complications of malaria, was also detected. Furthermore, a heterozygous variation in the iron-related transmembrane protease serine 6 (TMPRSS6) gene, rs855791 was found, which could have impacted the patient's iron status following two successive blood donations and exposure to malaria preceding the MS diagnosis. PSGT identifies relevant risk factors for demyelinating disorders resembling MS and uses the data for individualised treatment programs, and to systematically build a database that can provide evidence in large patient cohorts. Follow-up investigations may be suggested, such as whole exome sequencing in selected cases, to ensure that remyelination and restoration of function are achieved.

Maternal obesity and tobacco use modify the impact of genetic variants on the occurrence of conotruncal heart defects

Conotruncal heart defects (CTDs) are among the most severe birth defects worldwide. Studies of CTDs indicate both lifestyle behaviors and genetic variation contribute to the risk of CTDs. Based on a hybrid design using data from 616 case-parental and 1645 control-parental triads recruited for the National Birth Defects Prevention Study between 1997 and 2008, we investigated whether the occurrence of CTDs is associated with interactions between 921 maternal and/or fetal single nucleotide polymorphisms (SNPs) and maternal obesity and tobacco use. The maternal genotypes of the variants in the glutamate-cysteine ligase, catalytic subunit (GCLC) gene and the fetal genotypes of the variants in the glutathione S-transferase alpha 3 (GSTA3) gene were associated with an elevated risk of CTDs among obese mothers. The risk of delivering infants with CTDs among obese mothers carrying AC genotype for a variant in the GCLC gene (rs6458939) was 2.00 times the risk among those carrying CC genotype (95% confidence interval: 1.41, 2.38). The maternal genotypes of several variants in the glutathione-S-transferase (GST) family of genes and the fetal genotypes of the variants in the GCLC gene interacted with tobacco exposures to increase the risk of CTDs. Our study suggests that the genetic basis underlying susceptibility of the developing heart to the adverse effects of maternal obesity and tobacco use involve both maternal and embryonic genetic variants. These results may provide insights into the underlying pathophysiology of CTDs, and ultimately lead to novel prevention strategies.

Significance of dietary folate intake, homocysteine levels and MTHFR 677 C>T genotyping in South African patients diagnosed with depression: test development for clinical application

Low folate intake in the presence of the functional MTHFR 677 C > T (rs1801133) polymorphism is an important cause of elevated homocysteine levels previously implicated in major depressive disorder (MDD) and many other chronic diseases. In this study the clinical relevance and inter-relationship of these aspects were evaluated in 86 South African patients diagnosed with MDD and 97 population-matched controls participating in a chronic diseases screening program. A questionnaire-based clinical and nutrition assessment was performed, homocysteine levels determined, and all study participants genotyped for MTHFR 677 C > T (rs1801133) using allele-specific TaqMan technology. The folate score was found to be significantly lower in the patient group compared to controls (p = 0.003) and correlated with increased body mass index (BMI), particularly in females with MDD (p = 0.009). BMI was significantly higher in the MDD patients compared with controls after adjustment for age and sex (p = 0.015), but this association was no longer significant after further adjustment for the level of folate intake in the diet. In MDD patients but not controls, the minor T-allele of MTHFR 677 C > T was associated with increased BMI (p = 0.032), which in turn correlated significantly with increased homocysteine levels. The significant association between BMI and homocysteine levels was observed in both the MDD patient (p = 0.049) and control (p = 0.018) study groups. The significantly higher homocysteine levels observed in MDD patients compared to controls after adjustment for age and sex (p = 0.030), therefore appears to be mediated by the effects of MTHFR 677 C > T and low folate intake on BMI. Detection of the low-penetrance MTHFR 677 C > T mutation reinforces the importance of folate intake above the recommended daily dose to prevent or restore dysfunction of the methylation pathway.