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Objectives: To explore current management practices for PMR by general practitioners (GPs) and rheumatologists including implications for clinical trial recruitment., Methods: An English language questionnaire was constructed by a working group of rheumatologists and GPs from six countries. The questionnaire focused on: 1: Respondent characteristics; 2: Referral practices; 3: Treatment with glucocorticoids; 4: Diagnostics; 5: Comorbidities; and 6: Barriers to research. The questionnaire was distributed to rheumatologists and GPs worldwide via members of the International PMR/Giant Cell Arteritis Study Group., Results: In total, 394 GPs and 937 rheumatologists responded to the survey. GPs referred a median of 25% of their suspected PMR patients for diagnosis and 50% of these were returned to their GP for management. In general, 39% of rheumatologists evaluated patients with suspected PMR >2 weeks after referral, and a median of 50% of patients had started prednisolone before rheumatologist evaluation. Direct comparison of initial treatment showed that the percentage prescribing >25 mg prednisolone daily for patients was 30% for GPs and 12% for rheumatologists. Diagnostic imaging was rarely used. More than half (56%) of rheumatologists experienced difficulties recruiting people with PMR to clinical trials., Conclusion: This large international survey indicates that a large proportion of people with PMR are not referred for diagnosis, and that the proportion of treatment-naive patients declined with increasing time from referral to assessment. Strategies are needed to change referral and management of people with PMR, to improve clinical practice and facilitate recruitment to clinical trials., (© The Author(s) 2023. Published by Oxford University Press on behalf of the British Society for Rheumatology. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

Objective: Tocilizumab plus prednisone induces sustained glucocorticoid-free remission in patients with GCA. However, its long-term benefits in new-onset vs relapsing disease are uncertain, and the value of weekly vs every-other-week dosing has not been evaluated., Methods: In Giant-Cell Arteritis Actemra (GiACTA) part 1, patients with new-onset or relapsing GCA received blinded tocilizumab weekly (TCZ QW), tocilizumab every-other-week (TCZ Q2W) or placebo for 52 weeks, with a prednisone taper. In part 2 (open-label), patients were treated at investigator discretion for 104 weeks. In this analysis, patients were evaluated according to their original treatment assignments, and outcomes beyond 52 weeks were assessed. Outcomes of interest included time to first flare and cumulative glucocorticoid exposure over 3 years according to baseline disease status., Results: Part 1 enrolled 250 patients; 215 entered part 2. At baseline, 48% had new-onset disease and 52% had relapsing disease. In patients with new-onset and relapsing disease, the median time to first flare in the TCZ QW group was 577 and 575 days, respectively, vs 479 and 428 days with TCZ Q2W and 179 and 224 days with placebo; the median cumulative glucocorticoid dose was 3068 mg and 2191 mg with TCZ QW, 4080 mg and 2353 mg with TCZ Q2W, and 4639 mg and 6178 mg with placebo., Conclusion: TCZ QW delayed the time to flare and reduced the cumulative glucocorticoid dose in patients with relapsing GCA and new-onset GCA. These data support initiating TCZ QW as part of first-line therapy in all patients with active GCA., Trial Registration: ClinicalTrials.gov, https://clinicaltrials.gov, NCT01791153., (© The Author(s) 2021. Published by Oxford University Press on behalf of the British Society for Rheumatology.)

Objectives: We investigated the relationship between the ultrasonographic Halo Score and temporal artery biopsy (TAB) findings in GCA., Methods: This is a prospective study including 90 patients suspected of having GCA. Ultrasonography of temporal/axillary arteries and a TAB were obtained in all patients at baseline. An experienced pathologist evaluated whether TAB findings were consistent with GCA, and whether transmural inflammation, giant cells and intimal hyperplasia were present. Ultrasonographic Halo Scores were determined. Receiver operating characteristic analysis was performed., Results: Twenty-seven patients had a positive TAB, while 32 patients with a negative TAB received a clinical diagnosis of GCA after 6 months of follow-up. Patients with a positive TAB showed higher Halo Scores than patients with a negative TAB. The presence of intimal hyperplasia in the biopsy, rather than the presence of transmural inflammation or giant cells, was associated with elevated Halo Scores in patients with GCA. The Halo Score discriminated well between TAB-positive patients with and without intimal hyperplasia, as indicated by an area under the curve of 0.82 in the receiver operating characteristic analysis. Patients with a positive TAB and intimal hyperplasia more frequently presented with ocular ischaemia (40%) than the other patients with GCA (13-14%)., Conclusion: The ultrasonographic Halo Score may help to identify a subset of GCA patients with intimal hyperplasia, a TAB feature associated with ischaemic sight loss., (© The Author(s) 2020. Published by Oxford University Press on behalf of the British Society for Rheumatology.)

Objectives: This systematic review and meta-analysis aimed to evaluate the diagnostic value of the halo sign in the assessment of GCA., Methods: A systematic literature review was performed using MEDLINE, EMBASE and Cochrane central register databases up to August 2020. Studies informing on the sensitivity and specificity of the US halo sign for GCA (index test) were selected. Studies with a minimum of five participants were included. Study articles using clinical criteria, imaging such as PET-CT and/or temporal artery biopsy (TAB) as the reference standards were selected. Meta-analysis was conducted with a bivariate model., Results: The initial search yielded 4023 studies. Twenty-three studies (patients n  = 2711) met the inclusion criteria. Prospective (11 studies) and retrospective (12 studies) studies in academic and non-academic centres were included. Using clinical diagnosis as the standard (18 studies) yielded a pooled sensitivity of 67% (95% CI: 51, 80) and a specificity of 95% (95% CI: 89, 98%). This gave a positive and negative likelihood ratio for the diagnosis of GCA of 14.2 (95% CI: 5.7, 35.5) and 0.375 (95% CI: 0.22, 0.54), respectively. Using TAB as the standard (15 studies) yielded a pooled sensitivity of 63% (95% CI: 50, 75) and a specificity of 90% (95% CI: 81, 95)., Conclusion: The US halo sign is a sensitive and specific approach for GCA assessment and plays a pivotal role in diagnosis of GCA in routine clinical practice., Registration: PROSPERO 2020 CRD42020202179., (© The Author(s) 2021. Published by Oxford University Press on behalf of the British Society for Rheumatology.)

Objectives: To compare the ultrasound characteristics with clinical features, final diagnosis and outcome; and to evaluate the halo size following glucocorticoid treatment in patients with newly diagnosed GCA., Methods: Patients with suspected GCA, recruited from an international cohort, had an ultrasound of temporal (TA) and axillary (AX) arteries performed within 7 days of commencing glucocorticoids. We compared differences in clinical features at disease presentation, after 2 weeks and after 6 months, according to the presence or absence of halo sign. We undertook a cross-sectional analysis of the differences in halo thickness using Pearson's correlation coefficient (r) and Analysis of Variance (ANOVA)., Results: A total of 345 patients with 6 months follow-up data were included; 226 (65.5%) had a diagnosis of GCA. Jaw claudication and visual symptoms were more frequent in patients with halo sign (P =0.018 and P =0.003, respectively). Physical examination abnormalities were significantly associated with the presence of ipsilateral halo (P <0.05). Stenosis or occlusion on ultrasound failed to contribute to the diagnosis of GCA. During 7 days of glucocorticoid treatment, there was a consistent reduction in halo size in the TA (maximum halo size per patient: r=-0.30, P =0.001; and all halos r=-0.23, P <0.001), but not in the AX (P >0.05). However, the presence of halo at baseline failed to predict future ischaemic events occurring during follow-up., Conclusion: In newly diagnosed GCA, TA halo is associated with the presence of ischaemic features and its size decreases following glucocorticoid treatment, supporting its early use as a marker of disease activity, in addition to its diagnostic role., (© The Author(s) 2020. Published by Oxford University Press on behalf of the British Society for Rheumatology. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

Objectives: To develop a quantitative score based on colour duplex sonography (CDS) to predict the diagnosis and outcome of GCA., Methods: We selected patients with positive CDS and confirmed diagnosis of GCA recruited into the TA Biopsy (TAB) vs Ultrasound in Diagnosis of GCA (TABUL) study and in a validation, independent cohort. We fitted four CDS models including combinations of the following: number and distribution of halos at the TA branches, average and maximum intima-media thickness of TA and axillary arteries. We fitted four clinical/laboratory models. The combined CDS and clinical models were used to develop a score to predict risk of positive TAB and clinical outcome at 6 months., Results: We included 135 GCA patients from TABUL (female: 68%, age 73 (8) years) and 72 patients from the independent cohort (female: 46%, age 75 (7) years). The best-fitting CDS model for TAB used maximum intima-media thickness size and bilaterality of TA and axillary arteries' halos. The best-fitting clinical model included raised inflammatory markers, PMR, headache and ischaemic symptoms. By combining CDS and clinical models we derived a score to compute the probability of a positive TAB. Model discrimination was fair (area under the receiver operating characteristic curve 0.77, 95% CI: 0.68, 0.84). No significant association was found for prediction of clinical outcome at 6 months., Conclusion: A quantitative analysis of CDS and clinical characteristics is useful to identify patients with a positive biopsy, supporting the use of CDS as a surrogate tool to replace TAB. No predictive role was found for worse prognosis., (© The Author(s) 2019. Published by Oxford University Press on behalf of the British Society for Rheumatology. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

The free-energy landscape of interaction between a medium-sized peptide, endothelin 1 (ET1), and its receptor, human endothelin type B receptor (hETB), was computed using multidimensional virtual-system coupled molecular dynamics, which controls the system's motions by introducing multiple reaction coordinates. The hETB embedded in lipid bilayer was immersed in explicit solvent. All molecules were expressed as all-atom models. The resultant free-energy landscape had five ranges with decreasing ET1-hETB distance: completely dissociative, outside-gate, gate, binding pocket, and genuine-bound ranges. In the completely dissociative range, no ET1-hETB interaction appeared. In the outside-gate range, an ET1-hETB attractive interaction was the fly-casting mechanism. In the gate range, the ET1 orientational variety decreased rapidly. In the binding pocket range, ET1 was in a narrow pathway with a steep free-energy slope. In the genuine-bound range, ET1 was in a stable free-energy basin. A G-protein-coupled receptor (GPCR) might capture its ligand from a distant place., (© The Author(s) 2019. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.)

Objective: We present 13 patients with retroperitoneal fibrosis, focusing on clinical features, radiological characteristics, treatments and their outcomes., Methods: Retrospective review of the medical records was performed of all retroperitoneal fibrosis patients diagnosed and treated in our department between 2012 and 2017., Results: Twelve patients were male, with a median age of 64 years. Eleven patients presented with abdominal pain or back pain or both. Aetiologies varied from idiopathic to malignancy and vasculitis. Twelve patients had PET scans. These showed 18 F-fluorodeoxyglucose-avid retroperitoneal soft tissue around the abdominal aorta in the vast majority, with five scans also demonstrating localized or generalized uptake by the aorta. In all cases except one, glucocorticoids were applied as the first-line therapy. Further immunosuppressive therapy was required in 10 cases., Conclusion: Our patients were male and older in age compared with the existing literature. PET scans were very helpful in diagnosis of retroperitoneal fibrosis. Rituximab was found to be an effective treatment in six of our patients.

GCA shares many clinical features with PMR and Takayasu arteritis. The current mainstay of therapy for all three conditions is glucocorticoid therapy. Given the chronic, relapsing nature of these conditions and the morbidity associated with glucocorticoid therapy, there is a need for better treatment options to induce and sustain remission with fewer adverse effects. Conventional immunosuppressive treatments have been studied and have a modest effect. There is a keen interest in biologic therapies with studies showing the efficacy of IL-6 antagonists in PMR and GCA. Recently the first two randomized clinical trials in Takayasu arteritis have been completed. A major challenge for all of these conditions is the lack of standardized measures to assess disease activity. Long-term studies are needed to evaluate the impact of biologic therapies showing potential on important clinical outcomes such as vascular damage, cost-effectiveness and quality of life. The optimal duration of treatment also needs to be assessed.

Glucocorticoids are the mainstay of treatment for GCA. Patients often require long-term treatment that may be associated with numerous adverse effects, depending on the dose and the duration of treatment. Trends in recent decades for glucocorticoid use in GCA suggest increasing cumulative doses and longer exposures. Common adverse events (AEs) reported in glucocorticoid-treated GCA patients include osteoporosis, hypercholesterolaemia, hypertension, posterior subcapsular cataract, infections, diabetes mellitus, Cushingoid appearance, adrenal insufficiency and aseptic necrosis of bone. AEs considered most worrisome by patients and rheumatologists include weight gain, psychological effects, osteoporosis, cardiometabolic complications and infections. The challenge is to maximize the benefit-risk ratio by giving the maximum glucocorticoid treatment necessary to control GCA initially and then to prevent relapse but to give the minimum treatment possible to avoid glucocorticoid-related AEs. We discuss the safety issues associated with long-term glucocorticoid use in patients with GCA and strategies for preventing glucocorticoid-related morbidity.

GCA and PMR are conditions of older persons that frequently overlap. The traditional concept of GCA has focused on cranial symptoms such as headache and visual disturbance, but extra-cranial manifestations such as constitutional symptoms, polymyalgia and limb claudication have also long been recognized. These symptoms may coincide with cranial GCA, occur as an independent clinical subset [large-vessel (LV) GCA] or overlap with PMR. Imaging studies have demonstrated that up to one-third of patients with PMR have subclinical LV inflammation at disease outset. The implication of this finding for PMR management is unclear. Pathophysiological studies have emphasized the pivotal role of dendritic cells (DCs) and T cells in the pathogenesis of GCA, and the activation of certain pattern recognition receptors on DCs may determine the clinical subset of GCA. In patients with only PMR clinically, it is conceivable that transmural arterial inflammation has either not yet started or is prevented by unexplored regulatory pathways. This concept is supported by vasculitis of peri-adventitial small-vessels and activated DCs in the adventitia of temporal arteries, in the absence of media-infiltrating T cells. This review examines the clinical and pathophysiological spectrum of GCA and its subsets with PMR, the role of newer imaging techniques for GCA diagnosis and the management of these diseases., (© The Author 2016. Published by Oxford University Press on behalf of the British Society for Rheumatology. All rights reserved. For Permissions, please email: journals.permissions@oup.com.)

Objective: To create a tool to predict probability of remission and low disease activity (LDA) in patients with RA being considered for anti-TNF treatment in clinical practice., Methods: We analysed data from GO-MORE, an open-label, multinational, prospective study in biologic-naïve patients with active RA (DAS28-ESR ⩾3.2) despite DMARD therapy. Patients received 50 mg s.c. golimumab (GLM) once monthly for 6 months. In secondary analyses, regression models were used to determine the best set of baseline factors to predict remission (DAS28-ESR <2.6) at month 6 and LDA (DAS28-ESR ⩽3.2) at month 1., Results: In 3280 efficacy-evaluable patients, of 12 factors included in initial regression models predicting remission or LDA, six were retained in final multivariable models. Greater likelihood of LDA and remission was associated with being male; younger age; lower HAQ, ESR (or CRP) and tender joint count (or swollen joint count) scores; and absence of comorbidities. In models predicting 1-, 3- and 6-month LDA or remission, area under the receiver operating curve was 0.648-0.809 (R(2) = 0.0397-0.1078). The models also predicted 6-month HAQ and EuroQoL-5-dimension scores. A series of matrices were developed to easily show predicted rates of remission and LDA., Conclusion: A matrix tool was developed to show predicted GLM treatment outcomes in patients with RA, based on a combination of six baseline characteristics. The tool could help provide practical guidance in selection of candidates for anti-TNF therapy., (© The Author 2016. Published by Oxford University Press on behalf of the British Society for Rheumatology.)

Objective: To identify numbers of participants in the UK Primary Sjögren's Syndrome Registry (UKPSSR) who would fulfil eligibility criteria for previous/current or potential clinical trials in primary SS (pSS) in order to optimize recruitment., Methods: We did a retrospective analysis of UKPSSR cohort data of 688 participants who had pSS with evaluable data., Results: In relation to previous/current trials, 75.2% fulfilled eligibility for the Belimumab in Subjects with Primary Sjögren's Syndrome study (Belimumab), 41.4% fulfilled eligibility for the Trial of Remicade in primary Sjögren's syndrome study (Infliximab), 35.4% for the Efficacy of Tocilizumab in Primary Sjögren's Syndrome study (Tocilizumab), 31.6% for the Tolerance and Efficacy of Rituximab in Sjögren's Disease study (Rituximab), 26.9% for the Trial of anti-B-cell therapy in pSS study (Rituximab) and 26.6% for the Efficacy and Safety of Abatacept in Patients With Primary Sjögren's Syndrome study (Abatacept). If recent measures of outcome, such as the EULAR Sjögren's Syndrome Patient Reported Index (ESSPRI) score ⩾5 (measure of patient symptoms) and the EULAR Sjögren's Syndrome Disease Activity Index (ESSDAI) score ⩾5 (measure of systemic disease activity) are incorporated into a study design, with requirements for an unstimulated salivary flow >0 and anti-Ro positivity, then the pool of eligible participants is reduced to 14.3%., Conclusion: The UKPSSR identified a number of options for trial design, including selection on ESSDAI ⩾5, ESSPRI ⩾5 and serological and other parameters., (© The Author 2015. Published by Oxford University Press on behalf of the British Society for Rheumatology. All rights reserved. For Permissions, please email: journals.permissions@oup.com.)

Objective: This study sets out to investigate the relationship between health status [EuroQol five-dimensions questionnaire (EQ-5D)] in primary SS and three of the European League Against Rheumatism (EULAR) SS outcome measures-the disease activity index (ESSDAI), the patient reported index (ESSPRI) and the sicca score. In particular, the goal was to establish whether there is a relationship between the EULAR outcome measures and quality of life., Methods: Health status was evaluated using a standardized measure developed by the EuroQol Group-the EQ5D. This permits calculation of two measures of health status: time trade-off (TTO) values and the EQ-5D visual analogue scale (VAS) scores. We used Spearman's rank correlation analysis to investigate the strength of association between health status and three EULAR measures of physician- and patient-reported disease activity in 639 patients from the UK primary SS registry (UKPSSR) cohort., Results: This study demonstrates that the EULAR SS disease-specific outcome measures are significantly correlated with health outcome values (P < 0.001). Higher scores on the ESSDAI, EULAR sicca score and ESSPRI are associated with poorer health states-i.e. lower TTO values and lower VAS scores. While all three are significantly correlated with TTO values and EQ-5D VAS scores, the effect is strongest for the ESSPRI., Conclusion: This study provides further evidence supporting the use of ESSDAI, EULAR sicca score and ESSPRI measures in the clinic. We also discuss the need for disease-specific measures of health status and their comparison with standardized health outcome measures., (© The Author 2014. Published by Oxford University Press on behalf of the British Society for Rheumatology. All rights reserved. For Permissions, please email: journals.permissions@oup.com.)

Objectives: To determine whether ischaemic manifestations of GCA are associated with pre-existing hypertension, atherosclerosis or area-level socio-economic deprivation., Methods: We conducted an observational study of rheumatologist/ophthalmologist-diagnosed GCA in eight UK centres. The main outcome measure was ischaemic manifestations observed during active GCA: visual loss/blurring, aura, diplopia, jaw/tongue/limb claudication, cerebral/myocardial ischaemia or scalp necrosis., Results: Out of 271 patients, 222 had ischaemic manifestations. Adjusted odds ratios (ORs) for the influence of hypertension and atherosclerosis were 1.6 (95% CI 0.8, 3.1) and 1.5 (0.6, 3.5). The most striking finding was an association of ischaemic manifestations with increasing Index of Deprivation 2007 score: OR 4.2 (95% CI 1.3, 13.6) for the most-deprived quartile compared with the least-deprived quartile. Similar effect sizes were seen within each recruitment centre. Deprivation was associated with smoking and negatively associated with previous polymyalgia. However, neither of these variables, nor hypertension or atherosclerosis, appeared responsible for mediating the effect of deprivation on ischaemic complications. Smoking was not associated with ischaemic manifestations. Median symptom duration before treatment was 30 days; after adjusting for symptom duration, the OR for ischaemic complications was 3.2 (95% CI 1.0, 10.8) for the most-deprived quartile compared with the least-deprived quartile., Conclusions: In GCA, area-level socio-economic deprivation was associated with ischaemic manifestations: this was not mediated by traditional cardiovascular risk factors. These findings are novel and require replication. Delay between first symptoms and treatment may play a role. Public awareness campaigns about GCA should aim especially to engage individuals living in more deprived areas to encourage early presentation and prompt treatment.

We evaluated the impact of clinic-based musculoskeletal ultrasonography (MSUS) on diagnosis and management of cases as seen in day-to-day rheumatology practice. Data were retrieved for demography, background condition, clinical findings, indications, regions scanned, and outcomes of MSUS, and categorised as: new-patients and follow-up. New-patient records were analysed as to whether MSUS had helped to confirm or change clinical diagnosis or was of no additional help. In follow-ups, we determined whether MSUS had helped in disease assessment, detection of co-existing problems or revision of diagnosis. Its impact on treatment decisions was noted. A total of 237 patients (146 women; mean age 55.9+/-17.2 years) had 264 regions scanned; hands,50.7%. In 78/237 (32.9%) there was disagreement between clinical and MSUS findings. Amongst new-patients (72), 13/39 (33.3%) referred with inflammatory arthritis had no MSUS evidence of inflammation in or around joints. In 76.3% it helped in confirming or changing diagnosis. Of the follow-ups (165), in 78.7%, 13.9% and 7.2% it helped in assessment, detection of co-existing problems and revision of diagnosis, respectively. MSUS influenced treatment in 45/165 (27.27%) cases. In 60/67 (89.55%) cases of rheumatoid arthritis (RA), it was done for disease assessment; in 31/60 (51.66%) it influenced treatment. MSUS, as a clinic-based service in rheumatology, has significant impact on the diagnosis and treatment of patients. This has potential to reduce diagnostic uncertainty and follow-up visits and ensure better outcomes.

Background: Polymyalgia rheumatica (PMR) is common and is usually diagnosed and managed in primary care. There are no generally accepted primary care criteria for diagnosis., Objectives: To identify what features are used to diagnose PMR, to benchmark these against diagnostic criteria and to identify features at diagnosis with prognostic significance., Methods: This was a retrospective cohort study of all patients diagnosed with PMR in three UK general practices between January 1994 and December 2003. The medical records were examined for features of PMR. The duration of steroid treatment was used as a proxy for duration of disease. Analysis of prognostic predictors was by Cox proportional hazards models., Results: One hundred and eighty-three patients were identified, giving an overall annual incidence of 11.3 per 10 000 patients aged 50 or over. The median age at diagnosis was 75 (interquartile range 69, 79) years: 138 (75%) were female. The most common diagnostic features were proximal muscle pain in 151 (82%), raised inflammatory markers in 160 (87%), clinical response to corticosteroids in 166 (91%) and normalization of inflammatory markers in 147 (81%). Twenty (11%) had normal inflammatory indices. The median duration of treatment was 1.4 years (interquartile range 0.8, 2.4). Female sex and raised inflammatory markers were independently associated with longer treatment: female hazard ratio 1.5 (1.0, 2.2) P = 0.047 and raised inflammatory markers 2.0 (1.2, 3.2) P = 0.01., Conclusions: Primary care practitioners do not use established criteria to diagnose PMR and sometimes diagnose the condition even when inflammatory markers are normal. This exposes patients to a risk of inappropriate steroid use.

Unlabelled: We present a software for combined synthesis, inference and simplification of signal transduction networks. The main idea of our method lies in representing observed indirect causal relationships as network paths and using techniques from combinatorial optimization to find the sparsest graph consistent with all experimental observations. We illustrate the biological usability of our software by applying it to a previously published signal transduction network and by using it to synthesize and simplify a novel network corresponding to activation-induced cell death in large granular lymphocyte leukemia., Availability: NET-SYNTHESIS is freely downloadable from http://www.cs.uic.edu/~dasgupta/network-synthesis/

Reconstruction of sibling relationships from genetic data is an important component of many biological applications. In particular, the growing application of molecular markers (microsatellites) to study wild populations of plant and animals has created the need for new computational methods of establishing pedigree relationships, such as sibgroups, among individuals in these populations. Most current methods for sibship reconstruction from microsatellite data use statistical and heuristic techniques that rely on a priori knowledge about various parameter distributions. Moreover, these methods are designed for data with large number of sampled loci and small family groups, both of which typically do not hold for wild populations. We present a deterministic technique that parsimoniously reconstructs sibling groups using only Mendelian laws of inheritance. We validate our approach using both simulated and real biological data and compare it to other methods. Our method is highly accurate on real data and compares favorably with other methods on simulated data with few loci and large family groups. It is the only method that does not rely on a priori knowledge about the population under study. Thus, our method is particularly appropriate for reconstructing sibling groups in wild populations.

Context: Familial tumoral calcinosis (TC) results from disruptions in phosphate metabolism and is characterized by high serum phosphate with normal or elevated 1,25 dihydroxyvitamin vitamin D concentrations and ectopic and vascular calcifications. Recessive loss-of-function mutations in UDP-N-acetyl-alpha-D-galactosamine-polypeptide N-acetylgalactosaminyltransferase 3 (GALNT3) and fibroblast growth factor-23 (FGF23) result in TC., Objective: The objective of the study was to determine the relationship between GALNT3 and FGF23 in familial TC., Design, Setting, and Patients: We assessed the major biochemical defects and potential genes involved in patients with TC., Intervention: Combination therapy consisted of the phosphate binder Sevelamer and the carbonic anhydrase inhibitor acetazolamide., Results: We report a patient homozygous for a GALNT3 exon 1 deletion, which is predicted to truncate the encoded protein. This patient had high serum FGF23 concentrations when assessed with a C-terminal FGF23 ELISA but low-normal FGF23 levels when tested with an ELISA for intact FGF23 concentrations. Matrix extracellular phosphoglycoprotein has been identified as a possible regulator of phosphate homeostasis. Serum matrix extracellular phosphoglycoprotein levels, however, were normal in the family with GALNT3-TC and a kindred with TC carrying the FGF23 S71G mutation. The tumoral masses of the patient with GALNT3-TC completely resolved after combination therapy., Conclusions: Our findings demonstrate that GALNT3 inactivation in patients with TC leads to inadequate production of biologically active FGF23 as the most likely cause of the hyperphosphatemic phenotype. Furthermore, combination therapy may be effective for reducing the tumoral burden associated with familial TC.