Is Cardiopulmonary Exercise Testing Predictive of Surgical Complications in Patients Undergoing Surgery for Ovarian Cancer?

Preoperative cardiopulmonary exercise testing (CPET) provides an objective assessment of functional capability. In other intra-abdominal surgical specialties, CPET outcomes are predictive of operative morbidity. However, in ovarian cancer surgery, its predictive value remains unknown. In this study, we evaluated the association between CPET performance and surgical morbidity in ovarian cancer patients. Secondly, we assessed the association between CPET performance and other surgical outcomes (i.e., hospital stay, readmission and residual disease). This was a retrospective cohort study of patients undergoing primary surgery for ovarian cancer between 2020 and 2023. CPET performance included peak oxygen uptake (VO2 max), ventilatory efficiency (VE/VO2) and anaerobic threshold. Outcomes were operative morbidity and included intra- and postoperative complications (Clavien-Dindo), hospital stay, readmission within 30 days and residual disease. A total of 142 patients were included. A lower VO2 peak and a higher VE/VCO2 were both associated with the occurrence of postoperative complications, and a poorer anaerobic threshold was associated with more transfusions. VE/VCO2 remained significantly associated after multivariate analysis (p = 0.035). None of the CPET outcomes were associated with length of stay, readmission or residual disease. In conclusion, VE/VCO2 was significantly associated with an increased risk of all-cause postoperative complications in ovarian cancer patients undergoing primary surgery.

Unmet vaccination need among children under the age of five attending the paediatric emergency department: a cross-sectional study in a large UK district general hospital.

OBJECTIVE: To estimate vaccination coverage among children under the age of five attending the paediatric emergency department (PED) using tetanus and MMR vaccination as a proxy. DESIGN: A cross-sectional observational study with a single data collection point for each participant. SETTING: A single large PED in Greater Manchester, England. PARTICIPANTS: Children (under 5 years old) attending the PED during October 2021. Participation was 'opt-out' and parents/carers were given until the end of the following month to request that their child's data be excluded. PRIMARY AND SECONDARY OUTCOME MEASURES: The primary outcome of interest was the percentage of children who were up-to-date with their routine childhood vaccinations at their time of attendance to the PED. Secondary outcome measures were the percentage of children who had received age-appropriate tetanus and MMR vaccination, and how these compared with local population data at the ages of 1, 2 and 5 years of age. RESULTS: One-third of under-5s in this study had unmet vaccination need and were missing at least one dose of either MMR or tetanus-containing vaccine. In older age groups, many were missing their tetanus boosters and only 1 in 5 of those eligible had received two doses of MMR. Those in younger age groups had vaccination coverage levels comparable to the local data, but still below the target of 95%. CONCLUSIONS: Those children eligible for preschool boosters (tetanus and MMR2) appear to have considerable unmet vaccination need. While the pandemic has had an impact, the observation that MMR2 uptake is considerably lower than tetanus booster (when they are scheduled together) warrants further investigation. Catch-up campaigns for MMR2 should focus on this cohort of children and the PED may offer an opportunity for an intervention. TRIAL REGISTRATION NUMBER: NCT04485624.

Numbers and types of neurological emergencies in England and the influence of socioeconomic deprivation: a retrospective analysis of hospital episode statistics data.

OBJECTIVES: In this first large-scale analysis of neurological emergency admissions in England, we determine the number and types of emergency admissions with neurological emergency diagnostic codes, how many are under the care of a neurologist or neurosurgeon and how such admissions vary by levels of deprivation. DESIGN: Retrospective empirical research employing a derived list of neurological emergency diagnostic codes SETTING: This study used the Hospital Episode Statistics data set for the financial year 2019/2020 based on 17 million in-year inpatient admissions in England including 6.5 million (100%) emergency admissions with any diagnosis codes. RESULTS: There were 1.4 million (21.2%) emergency inpatient admissions with a mention of any neurological code, approx. 248 455 (3.8%) with mention of a specific neurological emergency code from the derived list, and 72 485 (1.1%) included such a code as the primary reason for admission. The highest number of in-year admissions for adults was for epilepsy (145 995), with epilepsy as the primary diagnostic code in 15 945 (10.9%). Acute nerve root/spinal cord syndrome (41 215), head injury (29 235) and subarachnoid haemorrhage (18 505) accounted for the next three highest number of admissions. 3230 (1.4%) in-year emergency hospital admissions with mention of a neurological emergency code were under the care of a neurologist or neurosurgeon, with only 1315 (0.9%) admissions with mention of an epilepsy code under a neurologist. There was significant variation for epilepsy and functional neurological disorders (FNDs) in particular by Index of Multiple Deprivation decile. The association between deprivation and epilepsy and FND was significant with p-values of 2.5e-6 and 1.5e-8, respectively. CONCLUSIONS: This study has identified important findings in relation to the burden of neurological emergency admissions but further work is needed, with greater clinical engagement in diagnostic coding, to better understand the implications for workforce and changes to service delivery needing to be implemented.

Utility and reliability of the Clinical Frailty Scale in patients scheduled for major vascular surgery: a prospective, observational, multicentre observer-blinded study.

BACKGROUND: Frailty is a distinctive health state associated with a loss of physiological reserve that results in higher rates of perioperative complications and impaired return to pre-morbid functional status. It is prevalent in the vascular population; however routine assessment is not common despite national guidance to the contrary. We aimed to evaluate the reliability of the Clinical Frailty Scale in assessing frailty in the surgical vascular population. METHODS: In this prospective, observational, observer-blinded study, we compared assessment of frailty in patients scheduled for major vascular surgery attending the pre-operative assessment clinic using the Clinical Frailty Scale against the Edmonton Frailty Scale. The study investigator completed the Edmonton Frailty Scale assessment; this was compared to the Clinical Frailty Scale assessments performed by the pre-assessment consultant and pre-assessment nurse, who were blinded to the Edmonton Frailty Scale score. The inter-rater reliability of the Clinical Frailty Scale between the pre-assessment consultant and pre-assessment nurse was determined by comparing their frailty scores for each patient. RESULTS: Ninety-seven patients were included in the analysis (median age 72 years, 84% male and 16% female). There was a moderate level of agreement between the Edmonton and Clinical Frailty Scale score for both consultants (87.6% agreement) and pre-assessment nurses (87.6% agreement). There was a substantial level of agreement between consultants and pre-assessment nurses for the Clinical Frailty Scale (89.7% agreement) CONCLUSIONS: The Clinical Frailty Scale is a useful tool to assess frailty in the vascular surgical population. It is more practical than the Edmonton Frailty Scale: quick to complete, requires minimal training and can be used when physical disability is present. TRIAL REGISTRATION: The study was approved by the Wales Health and Care Research Ethics Service (REC reference 17/WA/0160, IRAS 201173). TRIAL REGISTRATION: NCT03403673. Registered 19 January 2018, https://clinicaltrials.gov/ct2/show/NCT03403673.

Supporting parents through stillbirth: A qualitative study exploring the views of health professionals and health care staff in three hospitals in England.

OBJECTIVE: To investigate the views of a range of hospital based health professionals and health care staff involved in the management of stillbirth. STUDY DESIGN: A qualitative pilot study informed by grounded theory conducted in three hospital trusts in the North East of England. In total, 21 consultant obstetricians, 3 trainees (including 1 senior trainee), 29 midwives, 3 midwife sonographers and 4 chaplains took part in six focus groups and two semi-structured interviews. RESULTS: Two different approaches in stillbirth management could be detected in our study. One approach emphasised the existing evidence-base and patient directed choice whilst the other emphasised tradition and profession-directed care. These differences were particularly apparent in choices over mode of delivery, and the location of women as well as the time interval between diagnosis of an IUD and delivery. The existence of these two approaches was underscored by a lack of high quality evidence. CONCLUSION: Robust, high quality evidence is needed regarding the longer term psychological and emotional sequelae of different modes of delivery and varying time intervals and locations of women between diagnosis and delivery in stillbirth. If the competing discourses demonstrated here are found elsewhere then such need to be considered in any future policy development, evidence implementation and training programmes.

Genome-wide association study of a nicotine metabolism biomarker in African American smokers: impact of chromosome 19 genetic influences.

BACKGROUND AND AIMS: The activity of CYP2A6, the major nicotine-inactivating enzyme, is measurable in smokers using the nicotine metabolite ratio (NMR; 3'hydroxycotinine/cotinine). Due to its role in nicotine clearance, the NMR is associated with smoking behaviours and response to pharmacotherapies. The NMR is highly heritable (~80%), and on average lower in African Americans (AA) versus whites. We previously identified several reduce and loss-of-function CYP2A6 variants common in individuals of African descent. Our current aim was to identify novel genetic influences on the NMR in AA smokers using genome-wide approaches. DESIGN: Genome-wide association study (GWAS). SETTING: Multiple sites within Canada and the United States. PARTICIPANTS: AA smokers from two clinical trials: Pharmacogenetics of Nicotine Addiction Treatment (PNAT)-2 (NCT01314001; n = 504) and Kick-it-at-Swope (KIS)-3 (NCT00666978; n = 450). MEASUREMENTS: Genome-wide SNP genotyping, the NMR (phenotype) and population substructure and NMR covariates. FINDINGS: Meta-analysis revealed three independent chromosome 19 signals (rs12459249, rs111645190 and rs185430475) associated with the NMR. The top overall hit, rs12459249 (P = 1.47e-39; beta = 0.59 per C (versus T) allele, SE = 0.045), located ~9.5 kb 3' of CYP2A6, remained genome-wide significant after controlling for the common (~10% in AA) non-functional CYP2A6*17 allele. In contrast, rs111645190 and rs185430475 were not genome-wide significant when controlling for CYP2A6*17. In total, 96 signals associated with the NMR were identified; many were not found in prior NMR GWASs in individuals of European descent. The top hits were also associated with the NMR in a third cohort of AA (KIS2; n = 480). None of the hits were in UGT or OCT2 genes. CONCLUSIONS: Three independent chromosome 19 signals account for ~20% of the variability in the nicotine metabolite ratio in African American smokers. The hits identified may contribute to inter-ethnic variability in nicotine metabolism, smoking behaviours and tobacco-related disease risk.

Pharmacogenetic Analysis of Functional Glutamate System Gene Variants and Clinical Response to Clozapine.

Altered glutamate neurotransmission is implicated in the etiology of schizophrenia (SCZ) and the pharmacogenetics of response to clozapine (CLZ), which is the drug of choice for treatment-resistant SCZ. Response to antipsychotic therapy is highly variable, although twin studies suggest a genetic component. We investigated the association of 10 glutamate system gene variants with CLZ response using standard genotyping procedures. GRM2 (rs4067 and rs2518461), SLC1A2 (rs4354668, rs4534557, and rs2901534), SLC6A9 (rs12037805, rs1978195, and rs16831558), GRIA1 (rs2195450), and GAD1 (rs3749034) were typed in 163 European SCZ/schizoaffective disorder patients deemed resistant or intolerant to previous pharmacotherapy. Response was assessed following 6 months of CLZ monotherapy using change in Brief Psychiatric Rating Scale (BPRS) scores. Categorical and continuous response variables were analyzed using χ2 tests and analysis of covariance, respectively. We report no significant associations following correction for multiple testing. Prior to correction, nominally significant associations were observed for SLC6A9, SLC1A2, GRM2, and GRIA1. Most notably, CC homozygotes of rs16831558 located in the glycine transporter 1 gene (SLC6A9) exhibited an allele dose-dependent improvement in positive symptoms compared to T allele carriers (puncorrected = 0.008, pcorrected = 0.08). To clarify the role of SLC6A9 in clinical response to antipsychotic medication, and CLZ in particular, this finding warrants further investigation in larger well-characterized samples.

Genome-wide association analysis identifies novel blood pressure loci and offers biological insights into cardiovascular risk.

Elevated blood pressure is the leading heritable risk factor for cardiovascular disease worldwide. We report genetic association of blood pressure (systolic, diastolic, pulse pressure) among UK Biobank participants of European ancestry with independent replication in other cohorts, and robust validation of 107 independent loci. We also identify new independent variants at 11 previously reported blood pressure loci. In combination with results from a range of in silico functional analyses and wet bench experiments, our findings highlight new biological pathways for blood pressure regulation enriched for genes expressed in vascular tissues and identify potential therapeutic targets for hypertension. Results from genetic risk score models raise the possibility of a precision medicine approach through early lifestyle intervention to offset the impact of blood pressure-raising genetic variants on future cardiovascular disease risk.

Allele-Skewed DNA Modification in the Brain: Relevance to a Schizophrenia GWAS.

Numerous recent studies have suggested that phenotypic effects of DNA sequence variants can be mediated or modulated by their epigenetic marks, such as allele-skewed DNA modification (ASM). Using Affymetrix SNP microarrays, we performed a comprehensive search of ASM effects in human post-mortem brain and sperm samples (total n = 256) from individuals with major psychosis and control individuals. Depending on the phenotypic category of the brain samples, 1.4%-7.5% of interrogated SNPs exhibited ASM effects. Next, we investigated ASM in the context of genetic studies of schizophrenia and detected that brain ASM SNPs were significantly overrepresented among sub-threshold SNPs from a schizophrenia genome-wide association study (GWAS). Brain ASM SNPs showed a much stronger enrichment in a schizophrenia GWAS than in 17 large GWASs of non-psychiatric diseases and traits, arguing that ASM effects are at least partially tissue specific. Studies of germline and control brain ASM SNPs supported a causal association between ASM and schizophrenia. Finally, significantly higher proportions of ASM SNPs than of non-ASM SNPs were detected at loci exhibiting epigenetic signatures of enhancers and promoters, and they were overrepresented within transcription factor binding regions and DNase I hypersensitive sites. All of these findings collectively indicate that ASM SNPs should be prioritized in follow-up GWASs.

CYP2A6 reduced activity gene variants confer reduction in lung cancer risk in African American smokers--findings from two independent populations.

We investigated genetic variation in CYP2A6 in relation to lung cancer risk among African American smokers, a high-risk population. Previously, we found that CYP2A6, a nicotine/nitrosamine metabolism gene, was associated with lung cancer risk in European Americans, but smoking habits, lung cancer risk and CYP2A6 gene variants differ significantly between European and African ancestry populations. Herein, African American ever-smokers, drawn from two independent lung cancer case-control studies, were genotyped for reduced activity CYP2A6 alleles and grouped by predicted metabolic activity. Lung cancer risk in the Southern Community Cohort Study (n = 494) was lower among CYP2A6 reduced versus normal metabolizers, as estimated by multivariate conditional logistic regression [odds ratio (OR) = 0.44; 95% confidence interval (CI) = 0.26-0.73] and by unconditional logistic regression (OR = 0.62; 95% CI = 0.41-0.94). The association was replicated in an independent study from MD Anderson Cancer Center (n = 407) (OR = 0.64; 95% CI = 0.42-0.98), and pooling the studies yielded an OR of 0.64 (95% CI = 0.48-0.86). Exploratory analyses revealed a significant interaction between CYP2A6 genotype and sex on the risk for lung cancer (Southern Community Cohort Study: P = 0.04; MD Anderson: P = 0.03; Pooled studies: P = 0.002) with a CYP2A6 effect in men only. These findings support a contribution of genetic variation in CYP2A6 to lung cancer risk among African American smokers, particularly men, whereby CYP2A6 genotypes associated with reduced metabolic activity confer a lower risk of developing lung cancer.

The role of leptin, melanocortin, and neurotrophin system genes on body weight in anorexia nervosa and bulimia nervosa.

OBJECTIVE: Although low weight is a key factor contributing to the high mortality in anorexia nervosa (AN), it is unclear how AN patients sustain low weight compared with bulimia nervosa (BN) patients with similar psychopathology. Studies of genes involved in appetite and weight regulation in eating disorders have yielded variable findings, in part due to small sample size and clinical heterogeneity. This study: (1) assessed the role of leptin, melanocortin, and neurotrophin genetic variants in conferring risk for AN and BN; and (2) explored the involvement of these genes in body mass index (BMI) variations within AN and BN. METHOD: Our sample consisted of 745 individuals with AN without a history of BN, 245 individuals with BN without a history of AN, and 321 controls. We genotyped 20 markers with known or putative function among genes selected from leptin, melanocortin, and neurotrophin systems. RESULTS: There were no significant differences in allele frequencies among individuals with AN, BN, and controls. AGRP rs13338499 polymorphism was associated with lowest illness-related BMI in those with AN (p = 0.0013), and NTRK2 rs1042571 was associated with highest BMI in those with BN (p = 0.0018). DISCUSSION: To our knowledge, this is the first study to address the issue of clinical heterogeneity in eating disorder genetic research and to explore the role of known or putatively functional markers in genes regulating appetite and weight in individuals with AN and BN. If replicated, our results may serve as an important first step toward gaining a better understanding of weight regulation in eating disorders.

Effects of antihypertensive treatment after acute stroke in the Continue or Stop Post-Stroke Antihypertensives Collaborative Study (COSSACS): a prospective, randomised, open, blinded-endpoint trial.

BACKGROUND: Up to 50% of patients with acute stroke are taking antihypertensive drugs on hospital admission. However, whether such treatment should be continued during the immediate post-stroke period is unclear. We therefore aimed to assess the efficacy and safety of continuing or stopping pre-existing antihypertensive drugs in patients who had recently had a stroke. METHODS: The Continue or Stop Post-Stroke Antihypertensives Collaborative Study (COSSACS) was a UK multicentre, prospective, randomised, open, blinded-endpoint trial. Patients were recruited at 49 UK National Institute for Health Research Stroke Research Network centres from January 1, 2003, to March 31, 2009. Patients aged over 18 years who were taking antihypertensive drugs were enrolled within 48 h of stroke and the last dose of antihypertensive drug. Patients were randomly assigned (1:1) by secure internet central randomisation to either continue or stop pre-existing antihypertensive drugs for 2 weeks. Patients and clinicians who randomly assigned patients were unmasked to group allocation. Clinicians who assessed 2-week outcomes and 6-month outcomes were masked to group allocation. The primary endpoint was death or dependency at 2 weeks, with dependency defined as a modified Rankin scale score greater than 3 points. Analysis was by intention to treat. This trial is registered with the International Standard Randomised Controlled Trial Register, number ISRCTN89712435. FINDINGS: 763 patients were assigned to continue (n=379) or stop (n=384) pre-existing antihypertensive drugs. 72 of 379 patients in the continue group and 82 of 384 patients in the stop group reached the primary endpoint (relative risk 0.86, 95% CI 0.65-1.14; p=0.3). The difference in systolic blood pressure at 2 weeks between the continue group and the stop group was 13 mm Hg (95% CI 10-17) and the difference in diastolic blood pressure was 8 mm Hg (6-10; difference between groups p<0.0001). No substantial differences were observed between groups in rates of serious adverse events, 6-month mortality, or major cardiovascular events. INTERPRETATION: Continuation of antihypertensive drugs did not reduce 2-week death or dependency, cardiovascular event rate, or mortality at 6 months. Lower blood pressure levels in those who continued antihypertensive treatment after acute mild stroke were not associated with an increase in adverse events. These neutral results might be because COSSACS was underpowered owing to early termination of the trial, and support the continuation of ongoing research trials. FUNDING: The Health Foundation and The Stroke Association.

Variants of the elongator protein 3 (ELP3) gene are associated with motor neuron degeneration.

Amyotrophic lateral sclerosis (ALS) is a spontaneous, relentlessly progressive motor neuron disease, usually resulting in death from respiratory failure within 3 years. Variation in the genes SOD1 and TARDBP accounts for a small percentage of cases, and other genes have shown association in both candidate gene and genome-wide studies, but the genetic causes remain largely unknown. We have performed two independent parallel studies, both implicating the RNA polymerase II component, ELP3, in axonal biology and neuronal degeneration. In the first, an association study of 1884 microsatellite markers, allelic variants of ELP3 were associated with ALS in three human populations comprising 1483 people (P=1.96 x 10(-9)). In the second, an independent mutagenesis screen in Drosophila for genes important in neuronal communication and survival identified two different loss of function mutations, both in ELP3 (R475K and R456K). Furthermore, knock down of ELP3 protein levels using antisense morpholinos in zebrafish embryos resulted in dose-dependent motor axonal abnormalities [Pearson correlation: -0.49, P=1.83 x 10(-12) (start codon morpholino) and -0.46, P=4.05 x 10(-9) (splice-site morpholino), and in humans, risk-associated ELP3 genotypes correlated with reduced brain ELP3 expression (P=0.01). These findings add to the growing body of evidence implicating the RNA processing pathway in neurodegeneration and suggest a critical role for ELP3 in neuron biology and of ELP3 variants in ALS.

Differential methylation of the X-chromosome is a possible source of discordance for bipolar disorder female monozygotic twins.

Monozygotic (MZ) twins may be subject to epigenetic modifications that could result in different patterns of gene expression. Several lines of evidence suggest that epigenetic factors may underlie mental disorders such as bipolar disorder (BD) and schizophrenia (SZ). One important epigenetic modification, of relevance to female MZ twins, is X-chromosome inactivation. Some MZ female twin pairs are discordant for monogenic X linked disorders because of differential X inactivation. We postulated that similar mechanisms may also occur in disorders with more complex inheritance including BD and SZ. Examination of X-chromosome inactivation patterns in DNA samples from blood and/or buccal swabs in a series of 63 female MZ twin pairs concordant or discordant for BD or SZ and healthy MZ controls suggests a potential contribution from X-linked loci to discordance within twin pairs for BD but is inconclusive for SZ. Discordant female bipolar twins showed greater differences in the methylation of the maternal and paternal X alleles than concordant twin pairs and suggest that differential skewing of X-chromosome inactivation may contribute to the discordance observed for bipolar disorder in female MZ twin pairs and the potential involvement of X-linked loci in the disorder.

Dopamine genes and pathological gambling in discordant sib-pairs.

Pathological gambling (PG) is an impulse control disorder that has been considered as a behavioral addiction. Recent studies have suggested the involvement of the dopaminergic system in addictions and impulse control disorders and associations of dopamine receptor genes (DRD1, DRD2, and DRD4) and PG have been reported. In the present study, 140 sib-pairs discordant for the diagnosis of PG (70 males and 70 females on each group) were recruited through the Gambling Outpatient Unit at the Institute of Psychiatry, University of Sao Paulo and were assessed by trained psychiatrists. A family-based association design was chosen to prevent population stratification. All subjects were genotyped for dopamine receptor genes (DRD1 -800 T/C, DRD2 TaqIA RFLP, DRD3 Ser9Gly, DRD4 48bp exon III VNTR, DRD5 (CA) repeat) and the dopamine transporter gene (SCL6A3 40 bp VNTR). Our results suggest the association of PG with DRD1 -800 T/C allele T (P = .03).

A central resource for accurate allele frequency estimation from pooled DNA genotyped on DNA microarrays.

Analysing pooled DNA on microarrays is an efficient way to genotype hundreds of individuals for thousands of markers for genome-wide association. Although direct comparison of case and control fluorescence scores is possible, correction for differential hybridization of alleles is important, particularly for rare single nucleotide polymorphisms. Such correction relies on heterozygous fluorescence scores and requires the genotyping of hundreds of individuals to obtain sufficient estimates of the correction factor, completely negating any benefit gained by pooling samples. We explore the effect of differential hybridization on test statistics and provide a solution to this problem in the form of a central resource for the accumulation of heterozygous fluorescence scores, allowing accurate allele frequency estimation at no extra cost.

The effect of haplotype-block definitions on inference of haplotype-block structure and htSNPs selection.

It has been recently suggested that the human genome is organized as a series of haplotype blocks, and efforts to create a genome-wide haplotype map are already underway. Several computational algorithms have been proposed to partition the genome. However, little is known about their behaviors in relation to the haplotype-block partitioning and haplotype-tagging SNPs selection. Here, we present a systematic comparison of three classes of haplotype-block partition definitions, a diversity-based method, a linkage-disequilibrium (LD)-based method, and a recombination-based method. The data used were derived from a coalescent simulation under both a uniform recombination model and one that assumes recombination hotspots. There were considerable differences in haplotype information loss in the measure of entropy when the partition methods were compared under different population-genetics scenarios. Under both recombination models, the results from the LD-based definition and the recombination-based definition were more similar to each other than were the results from the diversity-based definition. This work demonstrates that when undertaking haplotype-based association mapping, the choice of haplotype-block definition and SNP selection requires careful consideration.

TTF-1 and RET promoter SNPs: regulation of RET transcription in Hirschsprung's disease.

Single nucleotide polymorphisms (SNPs) of the coding regions of receptor tyrosine kinase gene (RET) are associated with Hirschsprung's disease (HSCR, aganglionic megacolon). These SNPs, individually or combined, may act as a low penetrance susceptibility locus and/or be in linkage disequilibrium (LD) with another susceptibility locus located in RET regulatory regions. Because two RET promoter SNPs have been found associated with HSCR, in LD with HSCR-associated RET coding region haplotypes, their implication in the transcriptional regulation of RET is of major interest. Analysis of 172 sporadic HSCR patients also revealed the presence of HSCR-associated RET promoter SNPs in LD with the main coding region RET haplotype observed in Chinese patients. By using a weighted logistic regression approach, we determined that of all SNPs tested in our study, the promoter SNPs are the most correlated to the disease. Functional analysis of the RET promoter SNPs in the context of additional 5' regulatory regions demonstrated that the HSCR-associated alleles decrease RET transcription. These SNPs overlap a TTF-1 binding site and TTF-1-activated RET transcription is also decreased by the HSCR-associated SNPs. Moreover, we identified an HSCR patient with a Gly322Ser TTF-1 mutation that compromises activation of transcription from HSCR-associated RET promoter haplotypes. Interestingly, we show that the pattern of RET and TTF-1 expression is coincident in developing human gut. We also present a detailed profile of the RET gene in our population, which provides an insight into the higher incidence of the disease in China.