A splice acceptor variant in RGS6 associated with intellectual disability, microcephaly, and cataracts disproportionately promotes expression of a subset of RGS6 isoforms.

Intellectual disability (ID) is associated with an increased risk of developing psychiatric disorders, suggesting a common underlying genetic factor. Importantly, altered signaling and/or expression of regulator of G protein signaling 6 (RGS6) is associated with ID and numerous psychiatric disorders. RGS6 is highly conserved and undergoes complex alternative mRNA splicing producing ~36 protein isoforms with high sequence similarity historically necessitating a global approach in functional studies. However, our recent analysis in mice revealed RGS6 is most highly expressed in CNS with RGS6L(+GGL) isoforms predominating. A previously reported genetic variant in intron 17 of RGS6 (c.1369-1G>C), associated with ID, may provide further clues into RGS6L(+GGL) isoform functional delineation. This variant was predicted to alter a highly conserved canonical 3' acceptor site creating an alternative branch point within exon 18 (included in a subset of RGS6L(+GGL) transcripts) and a frameshift forming an early stop codon. We previously identified this alternative splice site and demonstrated its use generates RGS6Lζ(+GGL) isoforms. Here, we show that the c.1369-1G>C variant disrupts the canonical, preferred (>90%) intron 17 splice site and leads to the exclusive use of the alternate exon 18 splice site, inducing disproportionate expression of a subset of isoforms, particularly RGS6Lζ(+GGL). Furthermore, RGS6 global knockout mice do not exhibit ID. Thus, ID caused by the c.1369-1G>C variant likely results from altered RGS6 isoform expression, rather than RGS6 isoform loss. In summary, these studies highlight the importance of proper RGS6 splicing and identify a previously unrecognized role of G protein signaling in ID.

Demographics, natural history and treatment outcomes of non-molar gestational choriocarcinoma: a UK population study.

OBJECTIVE: To investigate the demographics, natural history and treatment outcomes of non-molar gestational choriocarcinoma. DESIGN: A retrospective national population-based study. SETTING: UK 1995-2015. POPULATION: A total of 234 women with a diagnosis of gestational choriocarcinoma, in the absence of a prior molar pregnancy, managed at the UKs two gestational trophoblast centres in London and Sheffield. METHODS: Retrospective review of the patient's demographic and clinical data. Comparison with contemporary UK birth and pregnancy statistics. MAIN OUTCOMES: Incidence statistics for non-molar choriocarcinoma across the maternal age groups. Cure rates for patients by FIGO prognostic score group. RESULTS: Over the 21-year study period, there were 234 cases of non-molar gestational choriocarcinoma, giving an incidence of 1:66 775 relative to live births and 1:84 226 to viable pregnancies. For women aged under 20, the incidence relative to viable pregnancies was 1:223 494, for ages 30-34, 1:80 227, and for ages 40-45, 1:41 718. Treatment outcomes indicated an overall 94.4% cure rate. Divided by FIGO prognostic groups, the cure rates were low-risk group 100%, high-risk group 96% and ultra-high-risk group 80.5%. CONCLUSIONS: Non-molar gestational choriocarcinoma is a very rare diagnosis with little prior detailed information on the demographics and natural history. The data in this study give age-related incidence data based on a large national population study. The results also demonstrated the widely varying natural history of this rare malignancy and the marked correlation of disease incidence with rising maternal age. TWEETABLE ABSTRACT: National gestational choriocarcinoma database indicates a close association between increasing maternal age and incidence.

Lung metastases in low-risk gestational trophoblastic neoplasia: a retrospective cohort study.

OBJECTIVE: Presence of lung metastases in low-risk gestational trophoblastic neoplasia (GTN) is generally considered not to influence prognosis. However, in a recent study in the Netherlands, GTN patients with lung metastases had a higher recurrence rate and more disease-specific deaths compared with patients without metastases. The aim of the present study was to validate these findings in a different country. DESIGN: Historical cohort study. SETTING: Charing Cross Hospital, United Kingdom. POPULATION: A total of 1040 low-risk GTN patients treated with methotrexate (MTX) between 2002 and 2016 were identified: 65 with lung metastases (group 1) and 975 without metastases (group 2). METHODS: Baseline characteristics, MTX resistance, survival and recurrence rates were recorded and compared between both groups. MAIN OUTCOME MEASURES: MTX resistance, recurrence rate and survival. RESULTS: The occurrence of MTX resistance and median number of MTX courses to achieve remission was significantly higher in patients with lung metastases than patients without metastases (60% versus 38.9%, P = 0.001; and nine versus six courses, P < 0.001). All choriocarcinoma patients (n = 4) with lung metastases developed MTX resistance. The recurrence rate was also higher in group I (9.2% versus 2.7%; P = 0.012). Disease-specific survival was 100% in both groups. CONCLUSIONS: The presence of lung metastases at the start of MTX therapy is associated with increased incidence of MTX resistance and recurrence in low-risk GTN without affecting overall survival, which remains 100%. However, individuals with low-risk choriocarcinoma with lung metastases are likely to become resistant to MTX and primary multi-agent chemotherapy should be considered. TWEETABLE ABSTRACT: The presence of lung metastases appears to increase the risk of recurrence in low-risk GTN, but does not affect overall cure rates and survival.

Psychological Outcomes of Living Liver Donors From a Multicenter Prospective Study: Results From the Adult-to-Adult Living Donor Liver Transplantation Cohort Study2 (A2ALL-2).

Although single-center and cross-sectional studies have suggested a modest impact of liver donation on donor psychological well-being, few studies have assessed these outcomes prospectively among a large cohort. We conducted one of the largest, prospective, multicenter studies of psychological outcomes in living liver donors within the Adult-to-Adult Living Donor Liver Transplantation Cohort Study2 (A2ALL-2) consortium. In total, 271 (91%) of 297 eligible donors were interviewed at least once before donation and at 3, 6, 12, and 24 mo after donation using validated measures. We found that living liver donors reported low rates of major depressive (0-3%), alcohol abuse (2-5%), and anxiety syndromes (2-3%) at any given assessment in their first 2 years after donation. Between 4.7% and 9.6% of donors reported impaired mental well-being at various time points. We identified significant predictors for donors' perceptions of being better people and experiencing psychological growth following donation, including age, sex, relationship to recipient, ambivalence and motivation regarding donation, and feeling that donation would make life more worthwhile. Our results highlight the need for close psychosocial monitoring for those donors whose recipients died (n=27); some of those donors experienced guilt and concerns about responsibility. Careful screening and targeted, data-driven follow-up hold promise for optimizing psychological outcomes following this procedure for potentially vulnerable donors.

Social and Financial Outcomes of Living Liver Donation: A Prospective Investigation Within the Adult-to-Adult Living Donor Liver Transplantation Cohort Study 2 (A2ALL-2).

Because results from single-center (mostly kidney) donor studies demonstrate interpersonal relationship and financial strains for some donors, we conducted a liver donor study involving nine centers within the Adult-to-Adult Living Donor Liver Transplantation Cohort Study 2 (A2ALL-2) consortium. Among other initiatives, A2ALL-2 examined the nature of these outcomes following donation. Using validated measures, donors were prospectively surveyed before donation and at 3, 6, 12, and 24 mo after donation. Repeated-measures regression models were used to examine social relationship and financial outcomes over time and to identify relevant predictors. Of 297 eligible donors, 271 (91%) consented and were interviewed at least once. Relationship changes were positive overall across postdonation time points, with nearly one-third reporting improved donor family and spousal or partner relationships and >50% reporting improved recipient relationships. The majority of donors, however, reported cumulative out-of-pocket medical and nonmedical expenses, which were judged burdensome by 44% of donors. Lower income predicted burdensome donation costs. Those who anticipated financial concerns and who held nonprofessional positions before donation were more likely to experience adverse financial outcomes. These data support the need for initiatives to reduce financial burden.

A national audit of colonic interposition for esophageal replacement.

Esophageal replacement by colonic interposition is an uncommon procedure. This study sought to identify the frequency of this operation in England, identify techniques and associated problems, and also assess health-related quality of life (HR QOL) from the two largest centers performing this procedure. Hospital Episode Statistics were used to identify patients and centers undertaking colon interposition between March 2001 and March 2015. An online survey of UK consultants discussed methods and experience. HR QOL was assessed using the Short Form 36(SF-36v2) with additional gastrointestinal questions. Hospital Episode Statistics identified 328 interpositions (22 in pediatric hospitals). The two highest volume units did 42 and 45 operations, respectively. Thirty-four surgeons (79% response rate) replied to the survey. Fifty-two percent preferred to use the left colon with 81% preferring a substernal placement. The HR QOL survey was performed on 24 patients with a median of 3 years after surgery (ranging from 9 months to 10 years) from the two largest centers and a 56% response rate. Five patients had physical QOL scores above population average and 10 had mental scores above population average. All patients had early satiety, 20 described dysphagia, and 18 regularly took antireflux medication. There was an estimated mean loss of 13.1% body weight (10.6 kg) postoperatively and three patients still relied on a feeding tube for nutrition after an average of 3 years. Colon interposition results in an acceptable long-term QOL. Few centers regularly perform this operation, and centralizing to high-volume centers may lead to better outcomes.

Complications and Their Resolution in Recipients of Deceased and Living Donor Liver Transplants: Findings From the A2ALL Cohort Study.

The purpose of this study was to explore long-term complications in recipients of deceased donor liver transplant (DDLT) and living donor liver transplant (LDLT) in the Adult-to-Adult Living Donor Liver Transplantation Cohort Study (A2ALL). We analyzed 471 DDLTs and 565 LDLTs from 1998 to 2010 that were followed up to 10 years for 36 categories of complications. Probabilities of complications and their resolutions were estimated using the Kaplan-Meier method, and predictors were tested in Cox proportional hazards models. Median follow-up for DDLT and LDLT was 4.19 and 4.80 years, respectively. DDLT recipients were more likely to have hepatocellular carcinoma and higher disease severity, including Model for End-Stage Liver Disease score. Complications occurring with higher probability in LDLT included biliary-related complications and hepatic artery thrombosis. In DDLT, ascites, intra-abdominal bleeding, cardiac complications and pulmonary edema were significantly more probable. Development of chronic kidney disease stage 4 or 5 was less likely in LDLT recipients (hazard ratio [HR] 0.41, p = 0.02). DDLT and LDLT had similar risk of grade 4 complications (HR 0.89, p = 0.60), adjusted for other risk factors. Once a complication occurred, the time to resolution did not differ between LDLT and DDLT. Future efforts should be directed toward reducing the occurrence of complications after liver transplantation.

Risk of recurrent molar pregnancies following complete and partial hydatidiform moles.

STUDY QUESTION: What is the risk of further molar pregnancies for women with one or more hydatidiform moles (HM) in relation to molar subtype. SUMMARY ANSWER: Women with a complete hydatidiform mole (CM) have a 1 in 100 and 1 in 4 risk of further CM after one or two consecutive CM, respectively, while women with a partial hydatidiform mole (PM) have only a small increase in risk for further molar pregnancies. WHAT IS KNOWN ALREADY: Women with a molar pregnancy have an increased risk of further HM. A small subgroup of women with recurrent HM has an autosomal recessive condition, familial recurrent hydatidiform moles (FRHM), that predisposes them to molar pregnancies. STUDY DESIGN, SIZE, DURATION: A retrospective study of subsequent pregnancies in 16 000 women registered at a centralized referral centre, with a CM or PM, between 1990 and 2009. PARTICIPANTS/MATERIALS, SETTING, METHODS: One hundred and sixty-six women with two or more molar pregnancies were identified from electronic records and patient notes. Histopathological features of all molar tissue were reviewed in these cases and genotyping performed where diagnosis was not possible on the basis of histopathological features alone. In addition, genotyping of molar tissue was performed in all cases of women with three or more CM to establish whether the tissue was diploid and biparental or androgenetic. MAIN RESULTS AND THE ROLE OF CHANCE: This study confirms an increased recurrence risk of ∼1% for a second molar pregnancy and in addition that this risk is associated with CM rather than PM. The data further indicate that the risk of a third HM is associated almost exclusively with CM and enabled an estimate that 1 in 640 women registered with a CM has the rare condition FRHM. The study also found that there was no significant difference between the risk of developing gestational trophoblastic neoplasia (GTN) for typical sporadic CM and the diploid biparental CM associated with FRHM (GTN; proportion difference 0.05, Z = 0.87, P = 0.29). LIMITATIONS, REASONS FOR CAUTION: While pathology was reviewed for all women with two or more molar pregnancies, not all cases registered underwent central review particularly those women registered in the early 1990s. It is therefore possible that the total number of CM and PM may differ slightly from that stated. While women were followed for a minimum of 5 years, it is possible that some women may subsequently have further molar pregnancies that will not have been included in the present study. WIDER IMPLICATIONS OF THE FINDINGS: This is the largest study to date on recurrence for molar pregnancies, and as such provides the most detailed information so far regarding the risk of further molar pregnancies for women with a PM or CM. Furthermore, the data provide new insights into the incidence of the rare autosomal recessive condition, FRHM, important information for counselling women with molar pregnancies. STUDY FUNDING/COMPETING INTERESTS: No competing interests declared. No funding was obtained for this study.

No evidence for mutations in NLRP7, NLRP2 or KHDC3L in women with unexplained recurrent pregnancy loss or infertility.

STUDY QUESTION: Are mutations in NLRP2/7 (NACHT, LRR and PYD domains-containing protein 2/7) or KHDC3L (KH Domain Containing 3 Like) associated with recurrent pregnancy loss (RPL) or infertility? SUMMARY ANSWER: We found no evidence for mutations in NLRP2/7 or KHDC3L in unexplained RPL or infertility. WHAT IS KNOWN ALREADY: Mutations in NLRP7 and KHDC3L are known to cause biparental hydatidiform moles (BiHMs), a rare form of pregnancy loss. NLRP2, while not associated with the BiHM pathology, is known to cause recurrent Beckwith Weidemann Syndrome (BWS). STUDY DESIGN, SIZE, AND DURATION: Ninety-four patients with well characterized, unexplained infertility were recruited over a 9-year period from three IVF clinics in Sweden. Blood samples from 24 patients with 3 or more consecutive miscarriages of unknown etiology were provided by the Recurrent Miscarriage Clinic at St Mary's Hospital, London, UK. PARTICIPANTS/MATERIALS, SETTING, METHODS: Patients were recruited into both cohorts following extensive clinical studies. Genomic DNA was isolated from peripheral blood and subject to Sanger sequencing of NLRP2, NLRP7 and KHDC3L. Sequence electropherograms were analyzed by Sequencher v5.0 software and variants compared with those observed in the 1000 Genomes, single nucleotide polymorphism database (dbSNP) and HapMap databases. Functional effects of non-synonymous variants were predicted using Polyphen-2 and sorting intolerant from tolerant (SIFT). MAIN RESULTS AND THE ROLE OF CHANCE: No disease-causing mutations were identified in NLRP2, NLRP7 and KHDC3L in our cohorts of unexplained infertility and RPL. LIMITATIONS, REASONS FOR CAUTION: Due to the limited patient size, it is difficult to conclude if the low frequency single nucleotide polymorphisms observed in the present study are causative of the phenotype. The design of the present study therefore is only capable of detecting highly penetrant mutations. WIDER IMPLICATIONS OF THE FINDINGS: The present study supports the hypothesis that mutations in NLRP7 and KHDC3L are specific for the BiHM phenotype and do not play a role in other adverse reproductive outcomes. Furthermore, to date, mutations in NLRP2 have only been associated with the imprinting disorder BWS in offspring and there is no evidence for a role in molar pregnancies, RPL or unexplained infertility. STUDY FUNDING/COMPETING INTERESTS: This study was funded by the following sources: Estonian Ministry of Education and Research (Grant SF0180044s09), Enterprise Estonia (Grant EU30020); Mentored Resident research project (Department of Obstetrics and Gynecology, Baylor College of Medicine); Imperial NIHR Biomedical Research Centre; Grant Number C06RR029965 from the National Center for Research Resources (NCCR; NIH). No competing interests declared.

The relationship of maternal age to molar pregnancy incidence, risks for chemotherapy and subsequent pregnancy outcome.

The national registration and treatment service for molar pregnancies in the UK allows for the collection of accurate data on this relatively rare diagnosis. In England and Wales, between 2000 and 2009, 5,793 patients with complete moles and 7,790 with partial moles were registered, compared with a total of 8,242,511 conceptions. The overall molar pregnancy incidence was 1 for every 607 conceptions (complete mole 1:1,423; partial mole 1:1,058), but with major variations with age. For complete moles, the risk varied from < 1:1,000 for ages 18-40, to 1:156 for women aged 45 and 1:8 for those aged 50 and above. The overall risk of requiring chemotherapy after a complete mole was 13.6% and 1.1% for partial mole, while the risk of a further molar pregnancy in the next conception was 1:68 but each of these figures have considerable variations with age. These modern statistics on molar pregnancy risks and outcomes should be of value to clinicians and their patients, while discussing this rare diagnosis.

Uterine artery pulsatility index: a predictor of methotrexate resistance in gestational trophoblastic neoplasia.

BACKGROUND: Neo-angiogenesis is a hallmark of cancer. The aim of this study was to test the hypothesis, in a prospective patient cohort, that in low-risk gestational trophoblastic neoplasia (LR-GTN) the uterine artery pulsatility index (UAPI), a measure of tumour vascularity, can predict resistance to methotrexate chemotherapy (MTX-R). METHODS: 286 LR-GTN patients (Charing Cross Hospital (CXH) score 0-8, or FIGO score 0-6) were treated with methotrexate between January 2008 and June 2011 at CXH. During staging investigations, patients underwent a Doppler ultrasound to assess the UAPI. RESULTS: 239 patients were assessable for both UAPI and MTX-R. The median UAPI was lower (higher vascularity) in MTX-R compared with MTX-sensitive patients (0.8 vs 1.4, P<0.0001). In multivariate logistic regression, UAPI≤1 predicted MTX-R, independent of both CXH and FIGO scores. The risk of MTX-R in patients with a FIGO score of 6 and UAPI≤1 was 100% vs 20% in patients with UAPI>1 (χ(2) P<0.0001). CONCLUSION: UAPI represents an independently validated clinically useful predictor of MTX-R in LR-GTN. Further, consideration of whether to incorporate UAPI into the FIGO scoring system is now warranted so that patients with a score of 6 and a UAPI ≤1 might be upstaged and offered combination chemotherapy rather than MTX.

Complications of living donor hepatic lobectomy--a comprehensive report.

A wider application of living donor liver transplantation is limited by donor morbidity concerns. An observational cohort of 760 living donors accepted for surgery and enrolled in the Adult-to-Adult Living Donor Liver Transplantation cohort study provides a comprehensive assessment of incidence, severity and natural history of living liver donation (LLD) complications. Donor morbidity (assessed by 29 specific complications), predictors, time from donation to complications and time from complication onset to resolution were measured outcomes over a 12-year period. Out of the 760 donor procedures, 20 were aborted and 740 were completed. Forty percent of donors had complications (557 complications among 296 donors), mostly Clavien grades 1 and 2. Most severe counted by complication category; grade 1 (minor, n = 232); grade 2 (possibly life-threatening, n = 269); grade 3 (residual disability, n = 5) and grade 4 (leading to death, n = 3). Hernias (7%) and psychological complications (3%) occurred >1 year postdonation. Complications risk increased with transfusion requirement, intraoperative hypotension and predonation serum bilirubin, but did not decline with the increased center experience with LLD. The probability of complication resolution within 1 year was overall 95%, but only 75% for hernias and 42% for psychological complications. This report comprehensively quantifies LLD complication risk and should inform decision making by potential donors and their caregivers.

Outcomes of living and deceased donor liver transplant recipients with hepatocellular carcinoma: results of the A2ALL cohort.

Hepatocellular carcinoma (HCC) represents an increasing fraction of liver transplant indications; the role of living donor liver transplant (LDLT) remains unclear. In the Adult-to-Adult Living Donor Liver Transplantation Cohort Study, patients with HCC and an LDLT or deceased donor liver transplant (DDLT) for which at least one potential living donor had been evaluated were compared for recurrence and posttransplant mortality rates. Mortality from date of evaluation of each recipient's first potential living donor was also analyzed. Unadjusted 5-year HCC recurrence was significantly higher after LDLT (38%) than DDLT (11%), (p = 0.0004). After adjustment for tumor characteristics, HCC recurrence remained significantly different between LDLT and DDLT recipients (hazard ratio (HR) = 2.35; p = 0.04) for the overall cohort but not for recipients transplanted following the introduction of MELD prioritization. Five-year posttransplant survival was similar in LDLT and DDLT recipients from time of transplant (HR = 1.32; p = 0.27) and from date of LDLT evaluation (HR = 0.73; p = 0.36). We conclude that the higher recurrence observed after LDLT is likely due to differences in tumor characteristics, pretransplant HCC management and waiting time.

The association between cytomegalovirus immune globulin and long-term recipient and graft survival following liver transplantation.

The association between cytomegalovirus (CMV) immune globulin (CMVIG) and long-term clinical outcomes has not been well defined. We examined the association between CMVIG and long-term recipient and graft survival in liver transplant recipients. Data were from the Scientific Registry of Transplant Recipients and included recipients transplanted between January 1995 and October 2008; follow-up was through March 2009. All recipients≤80 years of age with primary, single-organ liver transplants, given CMVIG with (n=2350) or without antivirals (n=455), antivirals without CMVIG (n = 32,939), or no CMV prophylaxis (n=28,508) before discharge were included. Kaplan-Meier analysis was used to examine rates of acute rejection (AR), graft loss, and death, over 7 years post transplantation. The adjusted risk of AR, graft loss, and death associated with CMVIG with and without antivirals vs. no prophylaxis was estimated using the Cox proportional hazards regression. In the univariate analysis, CMVIG, with and without antivirals, was associated with increased AR rates, but decreased mortality; CMVIG with antivirals was also associated with decreased graft loss compared with no prophylaxis. From the multivariable model, CMVIG with antivirals was associated with increased risk for AR, but decreased risk for graft loss and death; after adjustment, the association between CMVIG alone and mortality was not significant. CMVIG with antivirals is associated with increased risk of AR but greater long-term patient and graft survival after liver transplantation.

Protein Profiling of RGS6, a Pleiotropic Gene Implicated in Numerous Neuropsychiatric Disorders, Reveals Multi-Isoformic Expression and a Novel Brain-Specific Isoform.

A metanalysis identified regulator of G-protein signaling 6 (RGS6) as one of 23 loci with pleiotropic effects on four or more human psychiatric disorders. This finding is significant as it confirms/extends the findings of numerous other studies implicating RGS6 in CNS function and pathology. RGS6 is a highly conserved member of the RGS protein family whose cellular roles are likely affected by mRNA splicing and alternative domain inclusion/exclusion. Indeed, we previously identified multiple RGS6 splice variants predicted to produce 36 distinct protein isoforms containing either long (RGS6L) or short (RGS6S) N-terminal domains, an incomplete or intact GGL domain, and nine alternative C termini. Unfortunately, sequence similarities between the isoforms have made it difficult to confirm their individual existence and/or to determine their unique functions. Here, we developed three RGS6-specific antibodies that recognize all RGS6 protein isoforms (RGS6-fl), the N-terminus of RGS6L isoforms (RGS6-L), and an 18-amino acid alternate C-terminal sequence (RGS6-18). Using these antibodies, we demonstrate that RGS6L(+GGL) isoforms, predominating in both mouse (both sexes) CNS and peripheral tissues, are most highly expressed in the CNS. We further identify three novel RGS6 protein bands that are larger (61, 65, and 69-kDa) than the ubiquitously expressed 53- to 57-kDa RGS6L(+GGL) proteins. Importantly, we show that the 69-kDa protein is a brain-specific dephospho form of the 65-kDa band, the first identified phosphorylated RGS6 isoform. Together, these data begin to define the functional significance behind the complexity of RGS6 gene processing and further clarifies RGS6's physiological roles by resolving tissue-specific RGS6 protein expression.

Modeling Global Carbon Costs of Plant Nitrogen and Phosphorus Acquisition.

Most Earth system models (ESMs) do not explicitly represent the carbon (C) costs of plant nutrient acquisition, which leads to uncertainty in predictions of the current and future constraints to the land C sink. We integrate a plant productivity-optimizing nitrogen (N) and phosphorus (P) acquisition model (fixation & uptake of nutrients, FUN) into the energy exascale Earth system (E3SM) land model (ELM). Global plant N and P uptake are dynamically simulated by ELM-FUN based on the C costs of nutrient acquisition from mycorrhizae, direct root uptake, retranslocation from senescing leaves, and biological N fixation. We benchmarked ELM-FUN with three classes of products: ILAMB, a remotely sensed nutrient limitation product, and CMIP6 models; we found significant improvements in C cycle variables, although the lack of more observed nutrient data prevents a comprehensive level of benchmarking. Overall, we found N and P co-limitation for 80% of land area, with the remaining 20% being either predominantly N or P limited. Globally, the new model predicts that plants invested 4.1 Pg C yr-1 to acquire 841.8 Tg N yr-1 and 48.1 Tg P yr-1 (1994-2005), leading to significant downregulation of global net primary production (NPP). Global NPP is reduced by 20% with C costs of N and 50% with C costs of NP. Modeled and observed nutrient limitation agreement increases when N and P are considered together (r 2 from 0.73 to 0.83).

Shifts in plant respiration and carbon use efficiency at a large-scale drought experiment in the eastern Amazon.

*The effects of drought on the Amazon rainforest are potentially large but remain poorly understood. Here, carbon (C) cycling after 5 yr of a large-scale through-fall exclusion (TFE) experiment excluding about 50% of incident rainfall from an eastern Amazon rainforest was compared with a nearby control plot. *Principal C stocks and fluxes were intensively measured in 2005. Additional minor components were either quantified in later site measurements or derived from the available literature. *Total ecosystem respiration (R(eco)) and total plant C expenditure (PCE, the sum of net primary productivity (NPP) and autotrophic respiration (R(auto))), were elevated on the TFE plot relative to the control. The increase in PCE and R(eco) was mainly caused by a rise in R(auto) from foliage and roots. Heterotrophic respiration did not differ substantially between plots. NPP was 2.4 +/- 1.4 t C ha(-1) yr(-1) lower on the TFE than the control. Ecosystem carbon use efficiency, the proportion of PCE invested in NPP, was lower in the TFE plot (0.24 +/- 0.04) than in the control (0.32 +/- 0.04). *Drought caused by the TFE treatment appeared to drive fundamental shifts in ecosystem C cycling with potentially important consequences for long-term forest C storage.

A novel DFNB1 deletion allele supports the existence of a distant cis-regulatory region that controls GJB2 and GJB6 expression.

Eleven affected members of a large German-American family segregating recessively inherited, congenital, non-syndromic sensorineural hearing loss (SNHL) were found to be homozygous for the common 35delG mutation of GJB2, the gene encoding the gap junction protein Connexin 26. Surprisingly, four additional family members with bilateral profound SNHL carried only a single 35delG mutation. Previously, we demonstrated reduced expression of both GJB2 and GJB6 mRNA from the allele carried in trans with that bearing the 35delG mutation in these four persons. Using array comparative genome hybridization (array CGH), we have now identified on this allele a deletion of 131.4 kb whose proximal breakpoint lies more than 100 kb upstream of the transcriptional start sites of GJB2 and GJB6. This deletion, del(chr13:19,837,344-19,968,698), segregates as a completely penetrant DFNB1 allele in this family. It is not present in 528 persons with SNHL and monoallelic mutation of GJB2 or GJB6, and we have not identified any other candidate pathogenic copy number variation by arrayCGH in a subset of 10 such persons. Characterization of distant GJB2/GJB6 cis-regulatory regions evidenced by this allele may be required to find the 'missing' DFNB1 mutations that are believed to exist.

Identification of 13 novel NLRP7 mutations in 20 families with recurrent hydatidiform mole; missense mutations cluster in the leucine-rich region.

BACKGROUND: NLRP7 (NALP7) has recently been identified as the causative gene for familial recurrent hydatidiform mole (FRHM), a rare autosomal recessive condition in which affected women have recurrent molar pregnancies of diploid biparental origin. To date only a small number of affected families have been described. Our objectives were to investigate the diversity of mutations and their localisation to one or both isoforms of NLRP7, by screening a large series of women with FRHM and to examine the normal expression of NLRP7 in ovarian tissue. METHODS: Fluorescent microsatellite genotyping of molar tissue was used to establish a diagnosis of FRHM. Twenty families were subsequently screened for mutations in NLRP7 using DNA sequencing. Expression of NLRP7 in the ovary was examined by immunohistochemical staining. RESULTS: 16 different mutations were identified in the study, 13 of which were novel. Missense mutations were found to be present in transcript variant 2 of NLRP7 and cluster in the leucine-rich region (LRR). A man with two affected sisters and homozygous for the p.R693P mutation had normal reproductive outcomes. In the normal human ovary, NLRP7 expression is confined to the oocytes and present at all stages from primordial to tertiary follicles. CONCLUSION: 13 novel mutations in NLRP7 were identified. We confirm that mutations in NLRP7 affect female but not male reproduction, and provide evidence that transcript variant 2 of NLRP7 is the important isoform in this condition. The mutation clustering seen confirms that the LRR is critical for normal functioning of NLRP7.