Living with trimethylaminuria and body and breath malodour: personal perspectives.

BACKGROUND: Many people suffer from body and breath malodour syndromes. One of these is trimethylaminuria, a condition characterized by excretion in breath and bodily fluids of trimethylamine, a volatile and odorous chemical that has the smell of rotting fish. Trimethylaminuria can be primary, due to mutations in the gene encoding flavin-containing monooxygenase 3, or secondary, due to various causes. To gain a better understanding of problems faced by United Kingdom residents affected by body and breath malodour conditions, we conducted a survey. METHODS: Two anonymous online surveys, one for adults and one for parents/guardians of affected children, were conducted using the Opinio platform. Participants were invited via a trimethylaminuria advisory website. Questions were a mix of dropdown, checkbox and open-ended responses. Forty-four adults and three parents/guardians participated. The dropdown and checkbox responses were analysed using the Opinio platform. RESULTS: All participants reported symptoms of body/breath odour. However, not all answered every question. Twenty-three respondents experienced difficulties in being offered a diagnostic test for trimethylaminuria. Problems encountered included lack of awareness of the disorder by medical professionals and reluctance to recognise symptoms. Of those tested, 52% were diagnosed with trimethylaminuria. The main problems associated with living with body/breath malodours were bullying, harassment and ostracism in either the workplace (90%) or in social settings (88%). All respondents thought their condition had disadvantaged them in their daily lives. Open-ended responses included loss of confidence, stress, exclusion, isolation, loneliness, depression and suicidal thoughts. Respondents thought their lives could be improved by greater awareness and understanding of malodour conditions by medical professionals, employers and the general public, and appreciation that the malodour was due to a medical condition and not their fault. CONCLUSIONS: Breath and body malodour conditions can cause immense hardship and distress, both mentally and socially, having devastating effects on quality of life. It would be advantageous to establish a standardised pathway from primary care to a specialist unit with access to a robust and reliable test and diagnostic criteria. There is a need to recognise malodour disorders as a disability, giving affected individuals the same rights as those with currently recognised disabilities.

Epilepsy severity mediates association between mutation type and ADHD symptoms in tuberous sclerosis complex.

The association between attention-deficit/hyperactivity disorder (ADHD) and tuberous sclerosis complex (TSC) is widely reported, with support for the role of epilepsy, yet the mechanisms underlying the association across development are unclear. The Tuberous Sclerosis 2000 Study is a prospective longitudinal study of TSC. In Phase 1 of the study, baseline measures of epilepsy, cortical tuber load, and mutation were obtained with 125 children ages 0-16 years. In Phase 2, at an average of 8 years later, ADHD symptoms were measured for 81 of the participants. Structural equation modeling revealed an indirect pathway from genetic mutation, to cortical tuber load, to epileptic spasm severity in infancy, to ADHD symptoms in middle childhood and adolescence, in addition to a pathway linking current seizure severity to ADHD symptoms. Findings were retained when intelligence quotient (IQ) was entered as a correlated factor. The findings support a cascading developmental pathway to ADHD symptoms mediated by early-onset and severe epilepsy in the first 2 years of life. This warrants detailed investigation of seizure characteristics and cognitive and behavioral sequelae associated with ADHD from early in life, to further the understanding of the association between ADHD and early-onset epilepsy across syndromic and non-syndromic populations.

Children and adolescents' emotional problems during the COVID-19 pandemic in Brazil.

Brazil has been severely affected by the COVID-19 pandemic with one of the largest numbers of youth impacted by school closure globally. This longitudinal online survey assessed emotional problems in children and adolescents aged 5-17 years living in Brazil during the COVID-19 pandemic. Recruitment occurred between June to November 2020 and participants were invited for follow-up assessments every 15 days until June 2021. Participants were 5795 children and adolescents living across the country with mean age of 10.7 (SD 3.63) years at recruitment; 50.5% were boys and 69% of white ethnicity. Weighted prevalence rates of anxiety, depressive and total emotional symptoms at baseline were 29.7%, 36.1% and 36%, respectively. Longitudinal analysis included 3221 (55.6%) participants and revealed fluctuations in anxiety and depressive symptoms during one year follow-up, associated with periods of social mobility and mortality. Emotional problems significantly increased in July and September 2020 and decreased from December 2020 to February 2021 and then significantly increased in May 2021 relative to June 2020. Older age, feeling lonely, previous diagnosis of mental or neurodevelopmental disorder, previous exposure to traumatic events or psychological aggression, parental psychopathology, and sleeping less than 8/h a day were associated with increased rates of anxiety and depressive symptoms at baseline and over time. Food insecurity and less social contact with family and peers were associated with baseline anxiety and depressive symptoms, and lowest socio-economic strata, chronic disease requiring treatment and family members physically ill due to COVID-19 were associated with increasing rates over time. The pandemic severely affected youth, particularly those from vulnerable populations and in moments of increased mortality and decreased social mobility. Results underscore the need for allocation of resources to services and the continuous monitoring of mental health problems among children and adolescents.

Toward a neurocircuit-based taxonomy to guide treatment of obsessive-compulsive disorder.

An important challenge in mental health research is to translate findings from cognitive neuroscience and neuroimaging research into effective treatments that target the neurobiological alterations involved in psychiatric symptoms. To address this challenge, in this review we propose a heuristic neurocircuit-based taxonomy to guide the treatment of obsessive-compulsive disorder (OCD). We do this by integrating information from several sources. First, we provide case vignettes in which patients with OCD describe their symptoms and discuss different clinical profiles in the phenotypic expression of the condition. Second, we link variations in these clinical profiles to underlying neurocircuit dysfunctions, drawing on findings from neuropsychological and neuroimaging studies in OCD. Third, we consider behavioral, pharmacological, and neuromodulatory treatments that could target those specific neurocircuit dysfunctions. Finally, we suggest methods of testing this neurocircuit-based taxonomy as well as important limitations to this approach that should be considered in future research.

ADHD and autism symptoms in youth: a network analysis.

BACKGROUND: Previous research investigating the overlap between attention-deficit/hyperactivity disorder (ADHD) and autism spectrum disorder (henceforth, autism) symptoms in population samples have relied on latent variable modeling in which averaged scores representing dimensions were derived from observed symptoms. There are no studies evaluating how ADHD and autism symptoms interact at the level of individual symptom items. METHODS: We aimed to address this gap by performing a network analysis on data from a school survey of children aged 6-17 years old (N = 7,405). ADHD and autism symptoms were measured via parent-report on the Swanson, Nolan, Pelham-IV questionnaire and the Childhood Autism Spectrum test, respectively. RESULTS: A relatively low interconnectivity between ADHD and autism symptoms was found with only 10.06% of possible connections (edges) between one ADHD and one autism symptoms different than zero. Associations between ADHD and autism symptoms were significantly weaker than those between two symptoms pertaining to the same construct. Select ADHD symptoms, particularly those presenting in social contexts (e.g. 'talks excessively', 'does not wait turn'), showed moderate-to-strong associations with autism symptoms, but some were considered redundant to autism symptoms. CONCLUSIONS: The present findings indicate that individual ADHD and autism symptoms are largely segregated in accordance with diagnostic boundaries corresponding to these conditions in children and adolescents from the community. These findings could improve our clinical conceptualization of ADHD and autism and guide advancements in diagnosis and treatment.

Perinatal adversities in tuberous sclerosis complex: Determinants and neurodevelopmental outcomes.

AIM: To examine the association between perinatal adversities and neurodevelopmental outcome in tuberous sclerosis complex (TSC). METHOD: The Tuberous Sclerosis 2000 study is a prospective, longitudinal UK study of TSC. In phase 1, mutation type, TSC family history, tuber characteristics, presence of cardiac rhabdomyomas, seizure characteristics, and intellectual ability were assessed in 125 children affected with TSC (64 females, 61 males; median age 39mo, range 4-254). In phase 2, 88 participants (49 females, 39 males; median age 148mo, range 93-323) were assessed for neurodevelopmental outcomes including intellectual ability, autism spectrum disorder, and attention-deficit/hyperactivity disorder. Perinatal histories of 88 participants with TSC and 80 unaffected siblings were collected retrospectively using the Obstetric Enquiry Schedule and coded with a modified Gillberg Optimality Scale to measure levels of perinatal adversity. Data were analysed using Mann-Whitney U tests, Spearman's rank correlation, and linear regression with robust standard errors. RESULTS: Children with familial TSC experienced significantly greater perinatal adversity than unaffected siblings. Perinatal adversity was higher in children with TSC-affected mothers than those with unaffected mothers. There was no significant association between perinatal adversities and neurodevelopmental outcomes after controlling for confounders. INTERPRETATION: Maternal TSC is a significant marker of elevated perinatal risk in addition to risks incurred by fetal genotype. Pregnancies complicated by maternal or fetal TSC require higher vigilance, and mechanisms underlying increased perinatal adversity require further research. WHAT THIS PAPER ADDS: Higher perinatal adversity is associated with familial tuberous sclerosis complex (TSC). Maternal TSC was associated with higher frequencies of several perinatal risk markers. Paternal TSC was not associated with higher levels of perinatal adversity. Perinatal adversity levels in TSC1 and TSC2 subgroups did not differ significantly. Perinatal adversities were not associated with neurodevelopmental outcomes.

Recognizing sinonasal cancer in primary care: a matched case-control study using electronic records.

BACKGROUND: Cancers of the nasopharynx, nasal cavity, and accessory sinuses ("sinonasal") are rare in England, with around 750 patients diagnosed annually. There are no specific National Institute for Health and Care Excellence (NICE) referral guidelines for these cancers and no primary care research published. OBJECTIVE: To identify and quantify clinical features of sinonasal cancer in UK primary care patients. METHODS: This matched case-control study used UK Clinical Practice Research Datalink (CPRD) data. Patients were aged ≥40 years with a diagnosis of sinonasal cancer between January 1, 2000 and December 31, 2009 and had consulted their GP in the year before diagnosis. Clinical features of sinonasal cancer were analysed using conditional logistic regression. Positive predictive values (PPVs) for single and combined features were calculated. RESULTS: In total, 155 cases and 697 controls were studied. Nine symptoms and one abnormal investigation were significantly associated with the cancer: nasal mass; odds ratio, 95 (95% confidence interval 7.0, 1315, P = 0.001); head and neck lumps, 68 (12, 387, P < 0.001); epistaxis, 17 (3.9, 70, P < 0.001); rhinorrhoea, 14 (4.6, 44, P < 0.001); visual disturbance, 12 (2.2, 67, P = 0.004); sinusitis, 7.3 (2.2, 25, P = 0.001); sore throat, 6.0 (2.0, 18, P = 0.001); otalgia, 5.4 (1.6, 18, P = 0.007); headache, 3.6 (1.4, 9.5, P = 0.01); raised white cell count, 8.5 (2.8, 27, P < 0.001). Combined PPVs for epistaxis/rhinorrhoea, epistaxis/sinusitis, and rhinorrhoea/sinusitis were 0.62%. CONCLUSION: This is the first primary care study identifying epistaxis, sinusitis, and rhinorrhoea as part of the clinical prodrome of sinonasal cancer. Although no PPVs meet the 3% NICE referral threshold, these results may help clinicians identify who warrants safety-netting and possible specialist referral, potentially reducing the number of advanced-stage diagnoses of sinonasal cancer.

Sinonasal cancer occurs in the back of the nose or in the sinuses. It is rare in the United Kingdom, with most cases being diagnosed at an advanced stage. Delayed presentation and non-specific symptoms often lead to diagnosis at a later stage, with consequently poorer survival outcomes. Currently, there is no research describing the symptoms presented by these patients to their general practitioner (GP), nor referral guidelines for primary healthcare professionals. The aim of this study was to detect the symptoms of patients aged ≥40 years, diagnosed with sinonasal cancer in primary care. Three symptoms in the year before their diagnosis were linked with sinonasal cancer: nosebleeds, runny nose, and sinusitis. These symptoms may help GPs to identify possible sinonasal cancer patients earlier, though each symptom was low-risk on its own.

Promoting mother-infant relationships and underlying neural correlates: Results from a randomized controlled trial of a home-visiting program for adolescent mothers in Brazil.

Poverty and teenage pregnancy are common in low-and-middle-income countries and can impede the development of healthy parent-child relationships. This study aimed to test whether a home-visiting intervention could improve early attachment relationships between adolescent mothers and their infants living in poverty in Brazil. Analyses were conducted on secondary outcomes from a randomized controlled trial (NCT0280718) testing the efficacy of a home-visiting program, Primeiros Laços, on adolescent mothers' health and parenting skills and their infants' development. Pregnant youth were randomized to intervention (n = 40) or care-as-usual (CAU, n = 40) from the first trimester of pregnancy until infants were aged 24 months. Mother-infant attachment was coded during a mother-infant interaction when the infants were aged 12 months. Electrophysiological correlates of social processing (mean amplitude of the Nc component) were measured while infants viewed facial images of the mother and a stranger at age 6 months. Infants in the intervention group were more securely attached and more involved with their mothers than those receiving CAU at 12 months. Smaller Nc amplitudes to the mother's face at 6 months were associated with better social behavior at 12 months. Our findings indicate that the Primeiros Laços Program is effective in enhancing the development of mother-infant attachment.

Quantifying the impact of pre-existing conditions on the stage of oesophagogastric cancer at diagnosis: a primary care cohort study using electronic medical records.

BACKGROUND: Pre-existing conditions interfere with cancer diagnosis by offering diagnostic alternatives, competing for clinical attention or through patient surveillance. OBJECTIVE: To investigate associations between oesophagogastric cancer stage and pre-existing conditions. METHODS: Retrospective cohort study using Clinical Practice Research Datalink (CPRD) data, with English cancer registry linkage. Participants aged ≥40 years had consulted primary care in the year before their incident diagnosis of oesophagogastric cancer in 01/01/2010-31/12/2015. CPRD records pre-diagnosis were searched for codes denoting clinical features of oesophagogastric cancer and for pre-existing conditions, including those providing plausible diagnostic alternatives for those features. Logistic regression analysed associations between stage and multimorbidity (≥2 conditions; reference category: no multimorbidity) and having 'diagnostic alternative(s)', controlling for age, sex, deprivation and cancer site. RESULTS: Of 2444 participants provided, 695 (28%) were excluded for missing stage, leaving 1749 for analysis (1265/1749, 72.3% had advanced-stage disease). Multimorbidity was associated with stage [odds ratio 0.63, 95% confidence interval (CI) 0.47-0.85, P = 0.002], with moderate evidence of an interaction term with sex (1.76, 1.08-2.86, P = 0.024). There was no association between alternative explanations and stage (odds ratio 1.18, 95% CI 0.87-1.60, P = 0.278). CONCLUSIONS: In men, multimorbidity is associated with a reduced chance of advanced-stage oesophagogastric cancer, to levels seen collectively for women.

Diagnosing cancer is complicated by existing medical conditions. Diagnosis may be delayed if conditions explain cancer symptoms, or dominate appointments. Diagnosis may be quicker if conditions increase doctor­patient contact. We studied the association between existing illness and stage (early or advanced) of diagnosis with cancer of the stomach or gullet. We studied the primary-care records of patients aged ≥40 years, diagnosed in 01/01/2010­31/12/2015, and got stage from English cancer registry data. We searched the primary-care records for cancer symptoms (e.g. difficulty swallowing), and for 27 conditions that were common or explained cancer symptoms (e.g. difficulty swallowing following a stroke). We analysed cancer stage, looking at age, sex, multimorbidity (two or more conditions) and explanations for symptoms. We studied 1749 patients, of whom 1265 (72.3%) had advanced-stage cancer. The chance of advanced stage was similar in women with (71%, 95% CI 66­75%) or without (69%, 62­76%) multimorbidity. It was lower for men with (70%, 67­74%) than without (79%, 75­83%) multimorbidity. Stage of cancer was not affected by having explanations for cancer symptoms. In summary, for men, multimorbidity is associated with a reduced chance of advanced-stage cancer of the stomach or gullet to levels seen collectively for women.

Flavin-Containing Monooxygenase 1 Catalyzes the Production of Taurine from Hypotaurine.

Taurine is one of the most abundant amino acids in mammalian tissues. It is obtained from the diet and by de novo synthesis from cysteic acid or hypotaurine. Despite the discovery in 1954 that the oxygenation of hypotaurine produces taurine, the identification of an enzyme catalyzing this reaction has remained elusive. In large part, this is due to the incorrect assignment, in 1962, of the enzyme as an NAD-dependent hypotaurine dehydrogenase. For more than 55 years, the literature has continued to refer to this enzyme as such. Here we show, both in vivo and in vitro, that the enzyme that oxygenates hypotaurine to produce taurine is flavin-containing monooxygenase (FMO) 1. Metabolite analysis of the urine of Fmo1-null mice by 1H NMR spectroscopy revealed a buildup of hypotaurine and a deficit of taurine in comparison with the concentrations of these compounds in the urine of wild-type mice. In vitro assays confirmed that human FMO1 catalyzes the conversion of hypotaurine to taurine, utilizing either NADPH or NADH as cofactor. FMO1 has a wide substrate range and is best known as a xenobiotic- or drug-metabolizing enzyme. The identification that the endogenous molecule hypotaurine is a substrate for the FMO1-catalyzed production of taurine resolves a long-standing mystery. This finding should help establish the role FMO1 plays in a range of biologic processes in which taurine or its deficiency is implicated, including conjugation of bile acids, neurotransmitter, antioxidant and anti-inflammatory functions, and the pathogenesis of obesity and skeletal muscle disorders. SIGNIFICANCE STATEMENT: The identity of the enzyme that catalyzes the biosynthesis of taurine from hypotaurine has remained elusive. Here we show, both in vivo and in vitro, that flavin-containing monooxygenase 1 catalyzes the oxygenation of hypotaurine to produce taurine.

Look duration at the face as a developmental endophenotype: elucidating pathways to autism and ADHD.

Identifying developmental endophenotypes on the pathway between genetics and behavior is critical to uncovering the mechanisms underlying neurodevelopmental conditions. In this proof-of-principle study, we explored whether early disruptions in visual attention are a unique or shared candidate endophenotype of autism spectrum disorder (ASD) and attention-deficit/hyperactivity disorder (ADHD). We calculated the duration of the longest look (i.e., peak look) to faces in an array-based eye-tracking task for 335 14-month-old infants with and without first-degree relatives with ASD and/or ADHD. We leveraged parent-report and genotype data available for a proportion of these infants to evaluate the relation of looking behavior to familial (n = 285) and genetic liability (using polygenic scores, n = 185) as well as ASD and ADHD-relevant temperament traits at 2 years of age (shyness and inhibitory control, respectively, n = 272) and ASD and ADHD clinical traits at 6 years of age (n = 94).Results showed that longer peak looks at the face were associated with elevated polygenic scores for ADHD (ß = 0.078, p = .023), but not ASD (ß = 0.002, p = .944), and with elevated ADHD traits in mid-childhood (F(1,88) = 6.401, p = .013, $\eta _p^2$=0.068; ASD: F (1,88) = 3.218, p = .076), but not in toddlerhood (ps > 0.2). This pattern of results did not emerge when considering mean peak look duration across face and nonface stimuli. Thus, alterations in attention to faces during spontaneous visual exploration may be more consistent with a developmental endophenotype of ADHD than ASD. Our work shows that dissecting paths to neurodevelopmental conditions requires longitudinal data incorporating polygenic contribution, early neurocognitive function, and clinical phenotypic variation.

Flavin-containing monooxygenase 3 (FMO3): genetic variants and their consequences for drug metabolism and disease.

The review focuses on genetic variants of human flavin-containing monooxygenase 3 (FMO3) and their impact on enzyme activity, drug metabolism and disease.The majority of FMO-mediated metabolism in adult human liver is catalyzed by FMO3. Some drugs are metabolized in human liver predominantly by FMO3, but most drug substrates of FMO3 are metabolized also by other enzymes, particularly cytochromes P-450, and the FMO3-catalyzed reaction is not the major route of metabolism.Rare variants that severely affect production or activity of FMO3 cause the disorder trimethylaminuria and impair metabolism of drug substrates of FMO3. More common variants, particularly p.[(Glu158Lys);(Glu308Gly)], can moderately affect activity of FMO3 in vitro and reduce metabolism of drug substrates in vivo, in some cases increasing drug efficacy or toxicity.Common variants of FMO3 have been associated with a number of disorders, but additional studies are needed to confirm or refute such associations.Elevated plasma concentrations of trimethylamine N-oxide, a product of an FMO3-catalyzed reaction, have been implicated in certain diseases, particularly cardiovascular disease. However, the evidence is often contradictory and additional work is required to establish whether trimethylamine N-oxide is a cause, effect or biomarker of the disease.Genetic variants of other FMOs are also briefly discussed.

Early developmental pathways to childhood symptoms of attention-deficit hyperactivity disorder, anxiety and autism spectrum disorder.

BACKGROUND: Children with autism spectrum disorder (ASD) often have co-occurring symptoms of attention-deficit/hyperactivity disorder (ADHD) and/or anxiety. It is unclear whether these disorders arise from shared or distinct developmental pathways. We explored this question by testing the specificity of early-life (infant and toddler) predictors of mid-childhood ADHD and anxiety symptoms compared to ASD symptoms. METHODS: Infants (n = 104) at high and low familial risk for ASD took part in research assessments at 7, 14, 24 and 38 months, and 7 years of age. Symptoms of ASD, ADHD and anxiety were measured by parent report at age 7. Activity levels and inhibitory control, also measured by parent report, in infancy and toddlerhood were used as early-life predictors of ADHD symptoms. Fearfulness and shyness measured in infancy and toddlerhood were used as early-life predictors of anxiety symptoms. Correlations and path analysis models tested associations between early-life predictors and mid-childhood ADHD and anxiety symptoms compared to mid-childhood ASD symptoms, and the influence of controlling for ASD symptoms on those associations. RESULTS: Increased activity levels and poor inhibitory control were correlated with ADHD symptoms and not ASD or anxiety; these associations were unchanged in path models controlling for risk-group and ASD symptoms. Increased fearfulness and shyness were correlated with anxiety symptoms, but also ASD symptoms. When controlling for risk-group in path analysis, the association between shyness and anxiety became nonsignificant, and when further controlling for ASD symptoms the association between fearfulness and anxiety became marginal. CONCLUSIONS: The specificity of early-life predictors to ADHD symptoms suggests early developmental pathways to ADHD might be distinct from ASD. The overlap in early-life predictors of anxiety and ASD suggests that these disorders are difficult to differentiate early in life, which could reflect the presence of common developmental pathways or convergence in early behavioural manifestations of these disorders.

Effect of Flavin-Containing Monooxygenase Genotype, Mouse Strain, and Gender on Trimethylamine N-oxide Production, Plasma Cholesterol Concentration, and an Index of Atherosclerosis.

The objectives of the study were to determine the contribution, in mice, of members of the flavin-containing monooxygenase (FMO) family to the production of trimethylamine (TMA) N-oxide (TMAO), a potential proatherogenic molecule, and whether under normal dietary conditions differences in TMAO production were associated with changes in plasma cholesterol concentration or with an index of atherosclerosis (Als). Concentrations of urinary TMA and TMAO and plasma cholesterol were measured in 10-week-old male and female C57BL/6J and CD-1 mice and in mouse lines deficient in various Fmo genes (Fmo1-/- , 2-/- , 4-/- , and Fmo5-/- ). In female mice most TMA N-oxygenation was catalyzed by FMO3, but in both genders 11%-12% of TMA was converted to TMAO by FMO1. Gender-, Fmo genotype-, and strain-related differences in TMAO production were accompanied by opposite effects on plasma cholesterol concentration. Plasma cholesterol was negatively, but weakly, correlated with TMAO production and urinary TMAO concentration. Fmo genotype had no effect on Als. There was no correlation between Als and either TMAO production or urinary TMAO concentration. Our results indicate that under normal dietary conditions TMAO does not increase plasma cholesterol or act as a proatherogenic molecule.

Identification of Flavin-Containing Monooxygenase 5 (FMO5) as a Regulator of Glucose Homeostasis and a Potential Sensor of Gut Bacteria.

We have previously identified flavin-containing monooxygenase 5 (FMO5) as a regulator of metabolic aging. The aim of the present study was to investigate the role of FMO5 in glucose homeostasis and the impact of diet and gut flora on the phenotype of mice in which the Fmo5 gene has been disrupted (Fmo5-/- mice). In comparison with wild-type (WT) counterparts, Fmo5-/- mice are resistant to age-related changes in glucose homeostasis and maintain the higher glucose tolerance and insulin sensitivity characteristic of young animals. When fed a high-fat diet, they are protected against weight gain and reduction of insulin sensitivity. The phenotype of Fmo5-/- mice is independent of diet and the gut microbiome and is determined solely by the host genotype. Fmo5-/- mice have metabolic characteristics similar to those of germ-free mice, indicating that FMO5 plays a role in sensing or responding to gut bacteria. In WT mice, FMO5 is present in the mucosal epithelium of the gastrointestinal tract where it is induced in response to a high-fat diet. In comparison with WT mice, Fmo5-/- mice have fewer colonic goblet cells, and they differ in the production of the colonic hormone resistin-like molecule ßFmo5-/- mice have lower concentrations of tumor necrosis factor α in plasma and of complement component 3 in epididymal white adipose tissue, indicative of improved inflammatory tone. Our results implicate FMO5 as a regulator of body weight and of glucose disposal and insulin sensitivity and, thus, identify FMO5 as a potential novel therapeutic target for obesity and insulin resistance.

How useful is thrombocytosis in predicting an underlying cancer in primary care? a systematic review.

BACKGROUND: Although the association between raised platelet count (thrombocytosis) and cancer has been reported in primary and secondary care studies, UK GPs are unaware of it, and it is insufficiently evidenced for laboratories to identify and warn of it. This systematic review aimed to identify and collate evidence from studies that have investigated thrombocytosis as an early marker of cancer in primary care. METHODS: EMBASE (OvidSP), Medline (Ovid), Web of Science and The Cochrane Library were searched for relevant studies. Eligible studies had reported estimates of the association between thrombocytosis and cancer, in adults aged ≥40 in a primary care setting. Raw data from included studies were used to calculate positive predictive values and likelihood ratios (LRs) for cancer. RESULTS: Nine case-control studies were identified. Study quality was judged to be high. Included studies reported on the following cancer sites: colorectal, lung, ovary, bladder, kidney, pancreas, oesophago-gastric, uterus and breast. LRs indicated that thrombocytosis was a predictor of cancer in all sites except breast. In a consulting population, thrombocytosis is most highly predictive of lung and colorectal cancer. CONCLUSIONS: These results suggest that patients with thrombocytosis in primary care have an increased risk of cancer, and that some, but not all, cancers have raised platelets as an early marker. This finding is expected to be of use in primary care, for GPs receiving blood test results unexpectedly showing high platelet counts. Further research is needed to identify the cancers that are most strongly associated with thrombocytosis.

Trimethylamine and Trimethylamine N-Oxide, a Flavin-Containing Monooxygenase 3 (FMO3)-Mediated Host-Microbiome Metabolic Axis Implicated in Health and Disease.

Flavin-containing monooxygenase 3 (FMO3) is known primarily as an enzyme involved in the metabolism of therapeutic drugs. On a daily basis, however, we are exposed to one of the most abundant substrates of the enzyme trimethylamine (TMA), which is released from various dietary components by the action of gut bacteria. FMO3 converts the odorous TMA to nonodorous TMA N-oxide (TMAO), which is excreted in urine. Impaired FMO3 activity gives rise to the inherited disorder primary trimethylaminuria (TMAU). Affected individuals cannot produce TMAO and, consequently, excrete large amounts of TMA. A dysbiosis in gut bacteria can give rise to secondary TMAU. Recently, there has been much interest in FMO3 and its catalytic product, TMAO, because TMAO has been implicated in various conditions affecting health, including cardiovascular disease, reverse cholesterol transport, and glucose and lipid homeostasis. In this review, we consider the dietary components that can give rise to TMA, the gut bacteria involved in the production of TMA from dietary precursors, the metabolic reactions by which bacteria produce and use TMA, and the enzymes that catalyze the reactions. Also included is information on bacteria that produce TMA in the oral cavity and vagina, two key microbiome niches that can influence health. Finally, we discuss the importance of the TMA/TMAO microbiome-host axis in health and disease, considering factors that affect bacterial production and host metabolism of TMA, the involvement of TMAO and FMO3 in disease, and the implications of the host-microbiome axis for management of TMAU.

Relationships between flavin-containing mono-oxygenase 3 (FMO3) genotype and trimethylaminuria phenotype in a Japanese population.

AIM: The aim of this study was to investigate relationships between flavin-containing mono-oxygenase 3 (FMO3) genotype and phenotype (conversion of odorous trimethylamine into non-odorous trimethylamine N-oxide) in a large Japanese cohort suffering from trimethylaminuria. METHODS: Urinary excretion of trimethylamine and trimethylamine N-oxide was determined for 102 volunteers with self-reporting symptoms of trimethylaminuria. For each we determined the sequence of the entire coding region, plus 1.3 kb of flanking intronic and 2.5 kb of the upstream region of the FMO3 gene. The affect of upstream variants on transcription was determined with a reporter gene assay. RESULTS: Seventy-eight subjects were diagnosed as suffering from trimethylaminuria, based on urinary excretion of <90% of total TMA as TMA N-oxide. Of these, 13 were classified as severe, 56 as moderate and nine as mild cases, excreting <43%, 48-70% and 73-83% of trimethylamine as trimethylamine N-oxide, respectively. Twenty-seven mutations were identified in FMO3, 15 in the coding region, of which eight abolish or severely impair FMO3 activity (Pro70Leu, Cys197fsX, Thr201Lys, Arg205Cys, Met260Val, Trp388Ter, Gln470Ter and Arg500Ter), and 12 in the upstream region. The mutations segregate into 19 haplotypes, including four different combinations of upstream mutations, each of which reduces transcriptional activity in comparison with the ancestral upstream sequence of FMO3. CONCLUSIONS: Comparisons of genotype and phenotype reveal that severe trimethylaminuria is caused by loss of function mutations in FMO3. For moderate and mild cases the situation is more complex, with most resulting from factors other than FMO3 genotype. Our results have implications for the diagnosis and management of the disorder.

Mid-childhood autism sibling recurrence in infants with a family history of autism.

Autism sibling recurrence in prospective infant family history studies is ~20% at 3 years but systematic follow-up to mid-childhood is rare. In population and clinical cohorts autism is not recognized in some children until school-age or later. One hundred and fifty-nine infants with an older sibling with autism underwent research diagnostic assessments at 3 years and mid-childhood (6 to 12 years (mean 9)). We report the autism sibling recurrence rate in mid-childhood and compare developmental and behavioral profiles at mid-childhood and 3 years in those with earlier versus later recognized autism, and those who had, or had not, received a community autism diagnosis. The autism recurrence rate in this sample in mid-childhood was 37.1%, 95% CI [29.9%, 44.9%] and higher in boys than girls. Around half of those diagnosed with autism in mid-childhood had not received a diagnosis at 3 years. Later, diagnosis was more common in girls than boys. While some had sub-threshold symptoms at 3, in others late diagnosis followed a largely typical early presentation. Sibling recurrence based on community clinical diagnosis was 24.5%, 95% CI [18.4%, 31.9%]. Those who also had a community diagnosis tended to be older, have lower adaptive function and higher autism and inattention symptoms. Notwithstanding limitations of a single site study, modest sample size and limits to generalisability, autism sibling recurrence in family history infants may be higher in mid-childhood than in studies reporting diagnostic outcome at 3 years. Findings have implications for families and clinical services, and for prospective family history studies.