Autoimmune hyperphosphatemic tumoral calcinosis in a patient with FGF23 autoantibodies

Hyperphosphatemic familial tumoral calcinosis (HFTC)/hyperostosis-hyperphosphatemia syndrome (HHS) is an autosomal recessive disorder of ectopic calcification due to deficiency of or resistance to intact fibroblast growth factor 23 (iFGF23). Inactivating mutations in FGF23, N-acetylgalactosaminyltransferase 3 (GALNT3), or KLOTHO (KL) have been reported as causing HFTC/HHS. We present what we believe is the first identified case of autoimmune hyperphosphatemic tumoral calcinosis in an 8-year-old boy. In addition to the classical clinical and biochemical features of hyperphosphatemic tumoral calcinosis, the patient exhibited markedly elevated intact and C-terminal FGF23 levels, suggestive of FGF23 resistance. However, no mutations in FGF23, KL, or FGF receptor 1 (FGFR1) were identified. He subsequently developed type 1 diabetes mellitus, which raised the possibility of an autoimmune cause for hyperphosphatemic tumoral calcinosis. Luciferase immunoprecipitation systems revealed markedly elevated FGF23 autoantibodies without detectable FGFR1 or Klotho autoantibodies. Using an in vitro FGF23 functional assay, we found that the FGF23 autoantibodies in the patient's plasma blocked downstream signaling via the MAPK/ERK signaling pathway in a dose-dependent manner. Thus, this report describes the first case, to our knowledge, of autoimmune hyperphosphatemic tumoral calcinosis with pathogenic autoantibodies targeting FGF23. Identification of this pathophysiology extends the etiologic spectrum of hyperphosphatemic tumoral calcinosis and suggests that immunomodulatory therapy may be an effective treatment

Treatment of autosomal dominant hypocalcemia Type 1 with the calcilytic NPSP795 (SHP635)

Autosomal dominant hypocalcemia type 1 (ADH1) is a rare form of hypoparathyroidism caused by heterozygous, gain‐of‐function mutations of the calcium‐sensing receptor gene (CAR). Individuals are hypocalcemic with inappropriately low parathyroid hormone (PTH) secretion and relative hypercalciuria. Calcilytics are negative allosteric modulators of the extracellular calcium receptor (CaR) and therefore may have therapeutic benefits in ADH1. Five adults with ADH1 due to 4 distinct CAR mutations received escalating doses of the calcilytic compound NPSP795 (SHP635) on 3 consecutive days. Pharmacokinetics, pharmacodynamics, efficacy, and safety were assessed. Parallel in vitro testing with subject CaR mutations assessed the effects of NPSP795 on cytoplasmic calcium concentrations (Ca2+i), and ERK and p38MAPK phosphorylation. These effects were correlated with clinical responses to administration of NPSP795. NPSP795 increased plasma PTH levels in a concentration‐dependent manner up to 129% above baseline (p=0.013) at the highest exposure levels. Fractional excretion of calcium (FECa) trended down but not significantly so. Blood ionized calcium levels remained stable during NPSP795 infusion despite fasting, no calcitriol and little calcium supplementation. NPSP795 was generally safe and well‐tolerated. There was significant variability in response clinically across genotypes. In vitro, all mutant CaRs were half‐maximally activated (EC50) at lower concentrations of extracellular calcium (Ca2+o) compared to wild type (WT) CaR; NPSP795 exposure increased the EC50 for all CaR activity readouts. However, the in vitro responses to NPSP795 did not correlate with any clinical parameters. NPSP795 increased plasma PTH levels in subjects with ADH1 in a dose‐dependent manner, and thus, serves as proof‐of‐concept that calcilytics could be an effective treatment for ADH1. Albeit all mutations appear to be activating at the CaR, in vitro observations were not predictive of the in vivo phenotype, or the response to calcilytics, suggesting that other parameters impact the response to the drug

Phenotypic and Genotypic Characterization and Treatment of a Cohort with Familial Tumoral Calcinosis/Hyperostosis-Hyperphosphatemia Syndrome

Familial tumoral calcinosis (FTC)/hyperostosis-hyperphosphatemia syndrome (HHS) is a rare disorder caused by mutations in the genes encoding fibroblast growth factor-23 (FGF23), N-acetylgalactosaminyltransferase 3 (GALNT3), or KLOTHO. The result is functional deficiency of, or resistance to, intact FGF23 (iFGF23), causing hyperphosphatemia, increased renal tubular reabsorption of phosphorus (TRP), elevated or inappropriately normal 1,25-dihydroxyvitamin D3 (1,25D), ectopic calcifications and/or diaphyseal hyperostosis. Eight subjects with FTC/HHS were studied and treated. Clinical manifestations varied, even within families, ranging from asymptomatic to large, disabling calcifications. All subjects had hyperphosphatemia, increased TRP, and elevated or inappropriately normal 1,25D. C-terminal FGF23 was markedly elevated while iFGF23 was comparatively low, consistent with increased FGF23 cleavage. Radiographs ranged from diaphyseal hyperostosis to massive calcification. Two subjects with severe calcifications also had overwhelming systemic inflammation and elevated C-reactive protein (CRP). GALNT3 mutations were identified in 7 subjects; no causative mutation was found in the eighth. Biopsies from 4 subjects showed ectopic calcification and chronic inflammation, with areas of heterotopic ossification observed in 1 subject. Treatment with low phosphate diet, phosphate binders, and phosphaturia-inducing therapies was prescribed with variable response. One subject experienced complete resolution of a calcific mass after 13 months of medical treatment. In the 2 subjects with systemic inflammation, interleukin-1 (IL-1) antagonists significantly decreased CRP levels with resolution of calcinosis cutis and peri-lesional inflammation in one subject and improvement of overall well-being in both subjects. This cohort expands the phenotype and genotype of FTC/HHS and demonstrates the range of clinical manifestations despite similar biochemical profiles and genetic mutations. Overwhelming systemic inflammation has not been described previously in FTC/HHS; the response to IL-1 antagonists suggests that anti-inflammatory drugs may be useful adjuvants. In addition, this is the first description of heterotopic ossification reported in FTC/HHS, possibly mediated by the adjacent inflammation

The genetic architecture of the human cerebral cortex

The cerebral cortex underlies our complex cognitive capabilities, yet little is known about the specific genetic loci that influence human cortical structure. To identify genetic variants that affect cortical structure, we conducted a genome-wide association meta-analysis of brain magnetic resonance imaging data from 51,665 individuals. We analyzed the surface area and average thickness of the whole cortex and 34 regions with known functional specializations. We identified 199 significant loci and found significant enrichment for loci influencing total surface area within regulatory elements that are active during prenatal cortical development, supporting the radial unit hypothesis. Loci that affect regional surface area cluster near genes in Wnt signaling pathways, which influence progenitor expansion and areal identity. Variation in cortical structure is genetically correlated with cognitive function, Parkinson's disease, insomnia, depression, neuroticism, and attention deficit hyperactivity disorder

Finishing the euchromatic sequence of the human genome

The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead

Time perspective and socioeconomic status: A link to socioeconomic disparities in health?

Time perspective is a measure of the degree to which one's thinking is motivated by considerations of the future, present, or past. Time perspective has been proposed as a potential mediator of socioeconomic disparities in health because it has been associated with health behaviors and is presumed to vary with socioeconomic status. In this cross-sectional community-based survey of respondents recruited from hair salons and barber shops in a suburb of Washington DC, we examined the association between time perspective and both education level and occupation. We asked participants (N = 525) to complete a questionnaire that included three subscales (future, present-fatalistic, and present-hedonistic) of the Zimbardo Time Perspective Inventory. Participants with more formal education and those with professional occupations had higher scores on the future time perspective subscale, and lower scores on the present-fatalistic subscale, than participants with less formal education or a non-professional occupation. Present-fatalistic scores were also higher among participants whose parents had less formal education. Present-hedonistic scores were not associated with either education level or professional occupation. Time perspective scores were not independently associated with the likelihood of obesity, smoking, or exercise. In this community sample, future time perspective was associated with current socioeconomic status, and past-fatalistic time perspective was associated with both current and childhood socioeconomic status.USA Time perspective Socioeconomic status Health disparities

Testing the construct validity of a health transition question using vignette-guided patient ratings of health

Abstract Background A single-item transition question is often used to assess improvement or worsening in health, but its validity has not been tested extensively. The purpose of this study was to test the construct validity of a transition question by relating it to qualitative changes in patient’s self-rating of health guided by clinical vignettes. Methods We studied 169 patients with active rheumatoid arthritis (RA) before and after treatment escalation. At both assessments, patients scored their current health on a rating scale after first rating three vignettes describing mild, moderate, or severe RA. We classified patients into one of these three RA categories using a nearest-neighbor match. We then related the change in these self-rated categories between visits to responses to a transition question on visit 2. Results Sixty patients improved their RA vignette category after treatment, 86 remained in the same vignette category, and 23 worsened categories. On the transition question, 101 patients reported improvement, 48 reported no change, and 20 reported worsening, representing a modest association with changes in RA vignette categories (polychoric correlation r = 0.19). The association was stronger if patients who were in the mild RA category at both visits were also classified as improved if their self-rating changed from below to above their mild vignette rating (r = 0.23) and when incorporating the importance of changes on the transition question (r = 0.26). Conclusion Changes in health states, guided by clinical vignettes, support the construct validity of the transition question

Long-term outcomes of letrozole treatment for precocious puberty in girls with McCune-Albright syndrome.

OBJECTIVE: McCune-Albright syndrome (MAS) is a rare disorder with a spectrum including precocious puberty (PP) due to recurrent estrogen-secreting ovarian cysts. This study evaluates the long-term safety and efficacy of letrozole treatment in large cohort of girls with MAS-associated PP. DESIGN: Retrospective cohort analysis. METHODS: Clinical data were reviewed, including history and physical, bone age, and pelvic ultrasounds on 28 letrozole-treated girls. Adult height was reviewed for 42 historical controls. Outcomes included rate of skeletal maturation, growth velocity, predicted adult height, and adult height. RESULTS: Twenty-eight girls received letrozole treatment. Treatment duration was 4.1 ± 2.6 years (mean ± 1SD) (0.5–10.9, range) and mean follow-up was 6.0 ± 3.3 years (range 0.5-15.0), for a total of 135.9 person-years of follow-up. Letrozole was highly effective at decreasing the rate of skeletal maturation, with a decline in change in bone age over change in chronological age (ΔBA/ΔCA) from 1.7 (IQR 2.3) to 0.5 (IQR 0.4) (p<0.0001), and growth velocity Z-scores, which declined from 2.2 ± 2.3 to −0.6 ± 1.6 (p = 0.0004). Predicted adult height Z-scores increased significantly from −2.9 ± 3.2 to −0.8 ± 1.5 for subjects on treatment (p = 0.004). Four subjects who completed treatment reached adult height Z-scores ranging from −1.5 to 1.7 (median −0.6), which was increased in comparison to untreated historical controls (p=0.02). There was no change in uterine size or ovarian volumes, and no adverse events over the treatment period. CONCLUSIONS: In this study with the longest follow-up to date, letrozole treatment resulted in sustained beneficial effects on skeletal maturation, growth velocity and predicted adult height