ZNF687 mutations are frequently found in pagetic patients from South Italy: implication in the pathogenesis of Paget's disease of bone.

Paget's disease of bone (PDB) is a skeletal disorder whose molecular basis is not fully elucidated. However, 10% of patients show a familial PDB and 35% of them carry mutations in the SQSTM1 gene. We recently reported a founder mutation (p.Pro937Arg) in the ZNF687 gene, underlying PDB complicated by giant cell tumor (GCT/PDB) and rarely occurring in PDB patients without neoplastic degeneration. Since 80% of Italian GCT/PDB patients derive from Avellino, we hypothesized that ZNF687 mutation rate was higher in this region than elsewhere. Interestingly, our molecular analysis on 30 PDB patients showed that 33% hosted ZNF687 mutations, with the p.Pro937Arg identified in 8 familial cases. Two novel ZNF687 mutations (p.Pro665Leu and p.Gln784Glu) were detected in 2 sporadic patients. Only 2 subjects were positive for the p.Pro392Leu mutation in SQSTM1. ZNF687-mutated patients showed a severe PDB, with a remarkable number of affected sites. in vitro studies revealed that the ZNF687-mutant osteoclasts appeared as giant sized with up to 150 nuclei, never described in PDB. Finally, we also confirmed the causality of the p.Pro937Arg mutation in 4 additional GCT/PDB cases deriving from the same geographic area, indicating that PDB and GCT/PDB represent 2 sides of the same coin.

Autosomal-dominant myopia associated to a novel P4HA2 missense variant and defective collagen hydroxylation.

We recently described a complex multisystem syndrome in which mild-moderate myopia segregated as an independent trait. A plethora of genes has been related to sporadic and familial myopia. More recently, in Chinese patients severe myopia (MYP25, OMIM:617238) has been linked to mutations in P4HA2 gene. Seven family members complaining of reduced distance vision especially at dusk underwent complete ophthalmological examination. Whole-exome sequencing was performed to identify the gene responsible for myopia in the pedigree. Moderate myopia was diagnosed in the family which was associated to the novel missense variant c.1147A > G p.(Lys383Glu) in the prolyl 4-hydroxylase,alpha-polypeptide 2 (P4HA2) gene, which catalyzes the formation of 4-hydroxyproline residues in the collagen strands. In vitro studies demonstrated P4HA2 mRNA and protein reduced expression level as well as decreased collagen hydroxylation and deposition in mutated fibroblast primary cultures compared to healthy cell lines. This study suggests that P4HA2 mutations may lead to myopic axial elongation of eyeball as a consequence of quantitative and structural alterations of collagen. This is the first confirmatory study which associates a novel dominant missense variant in P4HA2 with myopia in Caucasian patients. Further studies in larger cohorts are advisable to fully clarify genotype-phenotype correlations.

A synaptobrevin-like gene in the Xq28 pseudoautosomal region undergoes X inactivation.

The X and Y chromosomes that maintain human dimorphism are thought to have descended from a single progenitor, with the Y chromosome becoming largely depleted of genes. A number of genes, however, retain copies on both X and Y chromosomes and escape the inactivation that affects most X-linked genes in somatic cells. Many of those genes are present in two pseudoautosomal regions (PARs) at the termini of the short (p) and long (q) arms of the sex chromosomes. For both PARs, pairing facilitates the exchange of information, ensuring the homogenisation of X and Y chromosomal material in these regions. We report here a strikingly different regulation of expression of a gene in Xq PAR. Unlike all Xp PAR genes studied so far, a synaptobrevin-like gene, tentatively named SYBL1, undergoes X inactivation. In addition, it is also inactive on the Y chromosome, thereby maintaining dosage compensation in an unprecedented way.

Confirmation that Xq27 and Xq28 are susceptibility loci for migraine in independent pedigrees and a case-control cohort.

Investigations into migraine genetics have suggested that susceptibility loci exist on the X chromosome. These reports are supported by evidence that demonstrates male probands as having a higher proportion of affected first-degree relatives as well as the female preponderance of 3:1 that the disorder displays. We have previously implicated the Xq24-28 locus in migraine using two independent multigenerational Australian pedigrees that demonstrated excess allele sharing at the Xq24, Xq27 and Xq28 loci. Here, we expand this work to investigate a further six independent migraine pedigrees using 11 microsatellite markers spanning the Xq27­28 region. Furthermore, 11 candidate genes are investigated in an Australian case-control cohort consisting of 500 cases and 500 controls. Microsatellite analysis showed evidence of excess allele sharing to the Xq27 marker DXS8043 (LOD* 1.38 P00.005) in MF879 whilst a second independent pedigree showed excess allele sharing to DXS8061 at Xq28 (LOD* 1.5 P00.004). Furthermore, analysis of these key markers in a case control cohort showed significant association to migraine in females at the DXS8043 marker (T1 P00.009) and association with MO at DXS8061 (T1 P00.05). Further analysis of 11 key genes across these regions showed significant association of a three-marker risk haplotype in the NSDHL gene at Xq28 (P00.0082). The results of this study add further support to the presence of migraine susceptibility loci on chromosome Xq27 and Xq28 as well as point to potential candidate genes in the regions that warrant further investigation.

Epidemiological, clinical, and genetic characteristics of Paget's disease of bone in a rural area of Calabria, Southern Italy.

BACKGROUND: The prevalence of Paget's disease of bone (PDB) is unknown in peninsular Southern Italy, although an elevated clinical severity of the disease was reported in patients from Campania. AIM: This study was performed to evaluate the epidemiological and genetic characteristics of PDB in a rural area of Calabria, the southernmost region in the Italian peninsula. SUBJECTS AND METHODS: We examined 1068 consecutive pelvic radiographs of patients older than 40 yr referred for any reason to the "Spinelli" Hospital, Belvedere Marittimo, from January 1st 2004 to December 31st 2006. In subjects with radiological findings of pelvic PDB, a 99m Technetium methylene diphosphonate bone scan and the sequence analysis of the sequestosome 1 (SQSTM1) gene were subsequently performed. RESULTS: In the examined geographic area, the crude radiographic prevalence of pelvic PDB was 0.74% (8/1068; male:female 5:3, mean age 71.6 ± 13.1 yr) whereas the estimated overall prevalence of PDB between 0.82% and 1.21%. PDB patients from Calabria showed clinical characteristics similar to those reported in patients from Campania. The disease was also frequently complicated by osteoarthritis and the right side of the body was more affected than the left. The SQSTM1 gene analysis revealed the presence of a novel missense mutation (M401V) in exon 8 in one subject with a familial and aggressive form of PDB. CONCLUSION: The study results confirmed that patients with PDB from rural districts of Southern Italy show an earlier onset and an increased clinical severity of the disease that appears mostly independent from the presence of germinal SQSTM1 mutations.

ZPLD1 gene is disrupted in a patient with balanced translocation that exhibits cerebral cavernous malformations.

The past few years have seen rapid advances in our understanding of the genetics and molecular biology of cerebral cavernous malformations (CCM) with the identification of the CCM1, CCM2, and CCM3 genes. Recently, we have recruited a patient with an X/3 balanced translocation that exhibits CCM. By fluorescent in situ hybridization analysis, sequence analysis tools and database mining procedures, we refined the critical region to an interval of 200-kb and identified the interrupted ZPLD1 gene. We detected that the mRNA expression level of ZPLD1 gene is consistently decreased 2.5-fold versus control (P=0.0006) with allelic loss of gene expression suggesting that this protein may be part of the complex signaling pathway implicated in CCM formation.

Identification and chromosomal localisation by fluorescence in situ hybridisation of human gene of phosphoinositide-specific phospholipase C beta(1).

Members of phosphoinositide-specific phospholipase C (PLC) families are central intermediary in signal transduction in response to the occupancy of receptors by many growth factors. Among PLC isoforms, the type beta(1) is of particular interest because of its reported nuclear localisation in addition to its presence at the plasma membrane. It has been previously shown that both the stimulation and the inhibition of the nuclear PLCbeta(1) under different stimuli implicate PLCbeta(1) as an important enzyme for mitogen-activated cell growth as well as for murine erythroleukaemia cell differentiation. The above findings hinting at a direct involvement of PLCbeta(1) in controlling the cell cycle in rodent cells, and the previously reported mapping of its gene in rat chromosome band 3q35-36, a region frequently rearranged in rat tumours induced by chemical carcinogenesis, prompted us to identify its human homologue. By screening a human foetal brain cDNA library with the rat PLCbeta(1) cDNA probe, we have identified a clone homologous to a sequence in gene bank called KIAA 0581, which encodes a large part of the human PLCbeta(1). By using this human cDNA in fluorescence in situ hybridisation on human metaphases, it has been possible to map human PLCbeta(1) on chromosome 20p12, confirming the synteny between rat chromosome 3 and human chromosome 20 and providing a novel locus of homology between bands q35-36 in rat and p12 in man. Since band 20p12 has been recently reported amplified and/or deleted in several solid tumours, the identification and chromosome mapping of human PLCbeta(1) could pave the way for further investigations on the role exerted both in normal human cells and in human tumours by PLCbeta(1), which has been shown to behave as a key signalling intermediate in the control of the cell cycle.

[Multifactorial disorder: molecular and evolutionary insights of uric acid nephrolithiasis]. / Malattie multifattoriali. Aspetti molecolari ed evolutivi della calcolosi renale da acido urico.

Nephrolithiasis is a common multifactorial disorder affecting about 10% of the Western populations and it is characterized by the presence of small crystals and stones in the urinary tract. Uric acid nephrolithiasis (UAN) accounts for 20% of all stones but its prevalence varies between countries. Nephrolithiasis is likely caused by several factors but a genetic component has clearly been demonstrated. While studying an ancient founder population in Sardinia, we recently identified a susceptibility locus for UAN on chromosome 10. In this region we identified a missense mutation in a specific isoform of a novel gene is strongly associated with UAN. Through a comparative genomic approach, we did not found a mouse homolog even if we were able to identify the corresponding genomic region, while in Old World monkey we found a canonical gene structure with several stop codons preventing protein production. We detected expression in New World monkeys while in humans we observe a functional protein. It seems, therefore, that, to avoid human disease, a fierce selection worked to develop a renal-haematic urate homeostasis system against excessive hyperuricaemia. ZNF365 emerged during primate evolution and assumed its role in parallel with the disappearance of uricase, probably against a disadvantageous excessive hyperuricaemia.

Mapping of 59 EST gene markers in 31 intervals spanning the human X chromosome.

The positioning of Expressed Sequence Tags (ESTs) constitutes an important step towards a functional map of the human genome, including candidate genes for human genetic disorders that have been localized by linkage analysis. We localized 59 ESTs on the human X chromosome, including 44 derived from infant brain and 15 from adult muscle cDNA libraries. Localizations by a somatic cell hybrid panel were refined for five cDNAs by mapping them in yeast artificial chromosome (YAC) contigs.

The evolutionary conservation of the human chitotriosidase gene in rodents and primates.

Chitinases have been identified in a variety of organisms ranging from prokaryotes to eukaryotes, known to specifically degrade chitin, an abundant polymer of N-acetylglucosamine. Recently a human chitinolytic enzyme called CHIT1 was discovered. CHIT1 is expressed by activated macrophages and hydrolyzes artificial chitotrioside substrates, but its specific function in humans is unknown, since it is generally believed that man completely lacks endogenous chitin and endogenous substrates for chitinases. An intriguing question is whether the chitotriosidase activity is just an evolutionary remnant or it has a physiological function in man. To test these hypotheses we utilized a "phylogenomic" approach performing accurate sequence analyses of this gene, coding for CHIT1, in rodents and primates. Inspecting the sequences available in public databases, we determined that this gene is conserved in rodents (mouse and rat) and primates (chimpanzee, gorilla, orangutan, gibbon, baboon, a common marmoset and black macaque). Moreover we found that a 24-base pair duplication that determines an enzymatically inactive human protein is not present in primates, suggesting that this polymorphism was created during human evolution. These results indicate that chitotriosidase is conserved across the evolutionary scale. Such conservation of the CHIT1 gene argues in favour of an important biological role.

The fairness of the PPS reimbursement methodology.

In FY 1984 the Medicare program implemented a new method of reimbursing hospitals for inpatient services, the Prospective Payment System (PPS). Under this system, hospitals are paid a predetermined amount per Medicare discharge, which varies according to certain patient and hospital characteristics. This article investigates the presence of systematic biases and other potential imperfections in the PPS reimbursement methodology as revealed by its effects on Medicare operating ratios. The study covers the first three years of the PPS (approximately 1984-1986) and is based on hospital data from the Medicare cost reports and other related sources. Regression techniques were applied to these data to determine how Medicare operating ratios were affected by specific aspects of the reimbursement methodology. Several possible imbalances were detected. The potential undercompensation relating to these can be harmful to certain classes of hospitals and to the Medicare populations that they serve.

Prospective payment system and other effects on post-hospital services.

The effects of the prospective payment system and other factors on the use of post-hospital services were investigated for four groups of diagnostically related Medicare discharges. Effects on specific services and total Medicare payments were analyzed at the beneficiary level using a Tobit regression technique. The utilization data base consisted of more than 30,000 discharge episode records for the years 1981-86. The post-hospital period for each Medicare beneficiary encompassed the 60 days following discharge from the hospital. Influences on both the level and timing of health care services during this period were appraised. The influence of the prospective payment system was measured through the financial impact and risk that it imposed on the discharging hospital.

Utilization effects of prescription drug benefits in an aging population.

In this article, the effects of prescription drug coverage on use are analyzed for beneficiaries of a large retiree health benefit fund in a quasi-experiment comparing new and established enrollees. Newer enrollees show an 18-percentage point greater increase in prescription drug expenditures per capita than established enrollees during the 3-year period following enrollment. This differential is interpreted as the insurance effect of prescription coverage. The impact was greater among high-cost drugs than among low-cost drugs, and also greater among low users of prescription drugs than among high users. No clear patterns were discerned across therapeutic categories.

Hospitalisation risks in the treatment of schizophrenia in a Medicaid population: comparison of antipsychotic medications.

This study used administrative claims data to compare the relative risks for hospitalisation among patients with schizophrenia within a US Medicaid programme receiving atypical and typical antipsychotics. The newer atypical antipsychotics may be better tolerated among mentally ill patients receiving public assistance (Medicaid) who are less functional than other mentally ill populations. Risperidone, olanzapine, quetiapine and ziprasidone were compared with each other and to typical antipsychotics as a single category. Cox proportional hazard estimates, adjusted for differences in patient characteristics, showed numerically lower risks for each of the atypicals in comparison with the typicals, with that for quetiapine being statistically significant (HR: 0.672, p = 0.0413). There were no statistically significant differences among atypical pairs. This study provides evidence that risk for hospitalisation among Medicaid patients with schizophrenia may be lower with atypical antipsychotics, particularly quetiapine.

Medicare payment options for recombinant erythropoietin therapy.

We analyzed alternative payment approaches that Medicare could use to pay for recombinant human erythropoietin (rHuEPO) therapy. How Medicare pays for rHuEPO therapy will affect whether providers make prudent purchases of the biologic and prescribe it appropriately and whether companies offer the program low prices. Medicare's policies may also guide policies of other third parties. Selecting payment options for Medicare payment requires balancing desirable and undesirable implications, especially trade-offs between improving access to and quality of care for beneficiaries versus constraining costs to Medicare and its beneficiaries. The options for paying providers that contain financial incentives to constrain expenditures also contain incentives for providers to skimp on use, perhaps to the detriment of patients' quality of care. On the other hand, options that may reward additional use may lead to higher expenditures and threaten the quality of care from the direction of overuse. Medicare currently varies the level and method of payment for rHuEPO therapy according to the setting in which it is provided. Equity among beneficiaries and providers and incentives for efficient use of medical services would argue for paying the same amount for the same service, regardless of where it was provided. Whatever payment options are adopted, the Health Care Financing Administration (HCFA) will have to be able to exercise flexibility in monitoring and responding to changing market conditions. In this dynamic market, the number of manufacturers, medical indications for use approved by the Food and Drug Administration, and, eventually, Medicare's predominance are likely to evolve over time. The appropriate level and perhaps even the method of payment may well change with market conditions.(ABSTRACT TRUNCATED AT 250 WORDS)

Recombinant erythropoietin and Medicare payment.

The biologic recombinant human erythropoietin provides a recent case study of the great influence federal policies, especially Medicare payment, exert over the use and cost of medical technologies. By covering most dialysis patients, Medicare has been the predominant payer for recombinant erythropoietin, which corrects anemia associated with chronic renal disease. Medicare's leverage seems to have produced a low US price for the product. Paying a fixed rate per treatment with the biologic agent gave dialysis facilities a financial incentive to use low doses, but Medicare did not routinely monitor patients' responses. By August 1990, average and modal doses were low, and fewer than 45% of patients who had been treated for 6 months or more had ever attained the target hematocrit. Medicare should recognize the financial incentives of its payment policies and routinely evaluate the quality of care for beneficiaries.

A novel pseudoautosomal human gene encodes a putative protein similar to Ac-like transposases.

We report the cloning of a novel gene, called Tramp, in the Xp/Yp PAR region that has a functional homologue on the Y chromosome and escapes X-inactivation. This gene encodes, within a single exon, a putative protein that has amino acid similarity with transposases of the Ac family. Flanking this gene we have identified putative terminal inverted repeats (TIRs) and a duplicate target site, suggesting that it may be an ancient transposable element. The nucleotide differences in these sites and the TIR-binding inactivity of the putative Tramp protein suggest that this element is not an autonomous transposon. In the human genome, the Tramp protein may be involved in the transposition of other transposable elements, like medium reiterated frequency repeats, or it could be specialized in the acquisition of a new cellular function.