Randomized investigation of increased dialyzer membrane hydrophilicity on hemocompatibility and performance.

BACKGROUND: Hemodialyzers should efficiently eliminate small and middle molecular uremic toxins and possess exceptional hemocompatibility to improve well-being of patients with end-stage kidney disease. However, performance and hemocompatibility get compromised during treatment due to adsorption of plasma proteins to the dialyzer membrane. Increased membrane hydrophilicity reduces protein adsorption to the membrane and was implemented in the novel FX CorAL dialyzer. The present randomized controlled trial compares performance and hemocompatibility profiles of the FX CorAL dialyzer to other commonly used dialyzers applied in hemodiafiltration treatments. METHODS: This prospective, open, controlled, multicentric, interventional, crossover study randomized stable patients on post-dilution online hemodiafiltration (HDF) to FX CorAL 600, FX CorDiax 600 (both Fresenius Medical Care) and xevonta Hi 15 (B. Braun) each for 4 weeks. Primary outcome was ß2-microglobulin removal rate (ß2-m RR). Non-inferiority and superiority of FX CorAL versus comparators were tested. Secondary endpoints were RR and/or clearance of small and middle molecules, and intra- and interdialytic profiles of hemocompatibility markers, with regards to complement activation, cell activation/inflammation, platelet activation and oxidative stress. Further endpoints were patient reported outcomes (PROs) and clinical safety. RESULTS: 82 patients were included and 76 analyzed as intention-to-treat (ITT) population. FX CorAL showed the highest ß2-m RR (76.28%), followed by FX CorDiax (75.69%) and xevonta (74.48%). Non-inferiority to both comparators and superiority to xevonta were statistically significant. Secondary endpoints related to middle molecules corroborated these results; performance for small molecules was comparable between dialyzers. Regarding intradialytic hemocompatibility, FX CorAL showed lower complement, white blood cell, and platelet activation. There were no differences in interdialytic hemocompatibility, PROs, or clinical safety. CONCLUSIONS: The novel FX CorAL with increased membrane hydrophilicity showed strong performance and a favorable hemocompatibility profile as compared to other commonly used dialyzers in clinical practice. Further long-term investigations should examine whether the benefits of FX CorAL will translate into improved cardiovascular and mortality endpoints. TRIAL REGISTRATION: eMPORA III registration on 19/01/2021 at ClinicalTrials.gov (NCT04714281).

Randomized comparison of three high-flux dialyzers during high-volume online hemodiafiltration-the comPERFORM study.

Background: Dialyzers should be designed to efficiently eliminate uraemic toxins during dialysis treatment, given that the accumulation of small and middle molecular weight uraemic solutes is associated with increased mortality risk of patients with end-stage renal disease. In the present study we investigated the novel FX CorAL dialyzer with a modified membrane surface for performance during online hemodiafiltration (HDF) in a clinical setting. Methods: comPERFORM was a prospective, open, controlled, multicentric, interventional, crossover study with randomized treatment sequences. It randomized stable patients receiving regular post-dilution online HDF to FX CorAL 600 (Fresenius Medical Care Deutschland), xevonta Hi 15 (B. Braun) and ELISIO 150H (Nipro) each for 1 week. The primary outcome was ß2-m removal rate (ß2-m RR) during online HDF. Secondary endpoints were RR and/or clearance of ß2-m and other molecules. Albumin removal over time was an exploratory endpoint. Non-inferiority and superiority of FX CorAL 600 versus comparators were tested. Results: Fifty-two patients were included and analysed. FX CorAL 600 showed the highest ß2-m RR (75.47%), followed by xevonta Hi 15 (74.01%) and ELISIO 150H (72.70%). Superiority to its comparators was statistically significant (P = 0.0216 and P < 0.0001, respectively). Secondary endpoints related to middle molecules affirmed these results. FX CorAL 600 demonstrated the lowest albumin removal up to 60 minutes and its sieving properties changed less over time than with comparators. Conclusions: FX CorAL 600 efficiently removed middle and small molecules and was superior to the two comparators in ß2-m RR. Albumin sieving kinetics point to reduced formation of a secondary membrane.

First pre-filled pen device with highly purified human menopausal gonadotropin (HP-hMG, Menopur) in liquid is shown to be bioequivalent to powder for reconstitution.

OBJECTIVE: To determine whether serum human follicle-stimulating hormone (FSH) levels after single subcutaneous dosing of highly purified human menopausal gonadotropins (HP-hMG) in a liquid formulation and a powder formulation are bioequivalent. MATERIALS AND METHODS: This was a randomized, two-way, crossover, single-dose, bioequivalence trial comparing Menopur liquid injected by pre-filled pen, with Menopur powder injected by conventional syringe and needle. The primary endpoints were AUCt and Cmax of baseline-adjusted FSH. Pituitary-suppressed, healthy women were administered single subcutaneous injections of 450 IU Menopur liquid (600 IU/0.96 mL) and 450 IU Menopur powder (by 2 subcutaneous injections of 225 IU in 1 mL) in a randomized order. The pharmacokinetic parameters of FSH and human chorionic gonadotropin (hCG) were assessed by non-compartmental methods with adjustment for endogenous pre-dose levels. RESULTS: In total, 76 women were randomized, and 56 completed the trial. The mean FSH and hCG serum concentration-time profiles were comparable between the two HP-hMG formulations. The geometric mean ratios and 90% confidence intervals of FSH for HP-hMG liquid versus HP-hMG powder were 1.12 (1.0562 - 1.1889) for AUCt and 1.17 (1.0946 - 1.2490) for Cmax, showing that the two formulations were bioequivalent. The incidence and severity of adverse events were similar between the two preparations, and both preparations were well tolerated. CONCLUSION: The 90% CIs for the geometric mean ratios of serum FSH AUCt and Cmax were both within 0.8000 - 1.2500, thus the two formulations are bioequivalent.

Performance and Hemocompatibility of a Novel Polysulfone Dialyzer: A Randomized Controlled Trial.

Background: High-flux dialyzers effectively remove uremic toxins, are hemocompatible to minimize intradialytic humoral and cellular stimulation, and have long-term effects on patient outcomes. A new dialyzer with a modified membrane surface has been tested for performance and hemocompatibility. Methods: This multicenter, prospective, randomized, crossover study involved the application of the new polysulfone-based FX CorAL 600 (Fresenius Medical Care, Bad Homburg, Germany), the polyarylethersulfone-based Polyflux 170H (Baxter Healthcare Corporation, Deerfield, IL), and the cellulose triacetate-based SureFlux 17UX (Nipro Medical Europe, Mechelen, Belgium), for 1 week each, to assess the noninferiority of the FX CorAL 600's removal rate of ß2-microglobulin. Performance was assessed by removal rate and clearance of small- and medium-sized molecules. Hemocompatibility was assessed through markers of complement, cell activation, contact activation, and coagulation. Results: Of 70 patients, 58 composed the intention-to-treat population. The FX CorAL 600's removal rate of ß2-microglobulin was noninferior to both comparators (P<0.001 versus SureFlux 17UX; P=0.0006 versus Polyflux 170H), and superior to the SureFlux 17UX. The activation of C3a and C5a with FX CorAL 600 was significantly lower 15 minutes after treatment start than with SureFlux 17UX. The activation of sC5b-9 with FX CorAL 600 was significantly lower over the whole treatment than with SureFlux 17UX, and lower after 60 minutes than with the Polyflux 170H. The treatments with FX CorAL 600 were well tolerated. Conclusions: FX CorAL 600 efficiently removed small- and medium-sized molecules, showed a favorable hemocompatibility profile, and was associated with a low frequency of adverse events in this study, with a limited patient number and follow-up time. Further studies, with longer observation times, are warranted to provide further evidence supporting the use of the new dialyzer in a wide range of therapeutic options, and for long-term treatment of patients on hemodialysis, to minimize the potential effects on inflammatory processes.

Pharmacodynamics and safety of the novel selective progesterone receptor modulator vilaprisan: a double-blind, randomized, placebo-controlled phase 1 trial in healthy women.

STUDY QUESTION: Does administration of vilaprisan (VPR) to healthy women for 12 weeks reduce menstrual bleeding? SUMMARY ANSWER: In this 12-week proof-of-concept phase 1 trial, most women (30/33, 90%) who received VPR at daily doses of 1-5 mg reported the absence of menstrual bleeding. WHAT IS KNOWN ALREADY: Vilaprisan (BAY 1002670) is a novel, highly potent selective progesterone receptor modulator that markedly reduces the growth of human leiomyoma tissue in a preclinical model of uterine fibroids (UFs). STUDY DESIGN, SIZE, DURATION: In this double-blind, parallel-group study, of the 163 healthy women enrolled 73 were randomized to daily VPR 0.1 mg (n = 12), 0.5 mg (n = 12), 1 mg (n = 13), 2 mg (n = 12), 5 mg (n = 12) or placebo tablets (n = 12) for 12 weeks. Participants were followed up until the start of the second menstrual bleeding after the end of treatment. Trial simulations were used to determine the minimum sample size required to estimate the non-bleeding rate (i.e. self-assessed bleeding intensity of 'none' or 'spotting') using Bayesian dose-response estimation with incorporated prior information. It was estimated that 48 participants in the per-protocol analysis population would be sufficient. PARTICIPANTS/MATERIALS, SETTING, METHODS: Women aged 18-45 years who had been sterilized by tubal ligation were enrolled between November 2011 and May 2012. Participants kept a daily diary of bleeding intensity. Blood and urine samples were taken, and transvaginal ultrasound was performed before treatment, during treatment and follow-up. Endometrial biopsies were obtained during the pretreatment cycle, at the end of the treatment period and during the follow-up phase. The primary outcome was the estimated dose-response curve of the observed non-bleeding rate during Days 10-84 of treatment, excluding the endometrial biopsy day and 2 days after biopsy. Secondary outcomes included return of bleeding during follow-up, size of follicle-like structures and serum hormone levels. Safety assessments included adverse events (AEs), endometrial thickness and histology, laboratory parameters, vital signs and 12-lead electrocardiography. MAIN RESULTS AND THE ROLE OF CHANCE: All 73 randomized participants received at least one dose of study medication and were included in safety analyses; six participants were excluded from the per-protocol analyses. A total of 69 completed the study. Observed non-bleeding rates increased with VPR dose: 0.1 mg (0%; 90% confidence interval [CI]: 0-23.8), 0.5 mg (27.3%; 90% CI: 7.9-56.4), 1 mg (80.0%; 90% CI: 49.3-96.3), 2 mg (100%; 90% CI: 77.9-100), 5 mg (90.9%; 90% CI: 63.6-99.5), compared with 0% (90% CI: 0-22.1) in the placebo group. Maximal non-bleeding rates were reached at doses of 2 mg and higher. Return of menstrual bleeding was observed in all women ≤52 days after VPR discontinuation. No treatment-emergent critical endometrial findings occurred. Follicular growth was not suppressed and minimum average estradiol levels remained above 40 pg/ml. No serious treatment-emergent AEs or study discontinuations due to AEs were reported. Clinically relevant changes in laboratory parameters or vital signs were not evident. LIMITATIONS, REASONS FOR CAUTION: The results of this small proof-of-concept study will need to be confirmed in larger trials in patients with UFs to establish the potential therapeutic benefits and safety of VPR. WIDER IMPLICATIONS OF THE FINDINGS: The high rates of non-bleeding (80-100% at VPR doses of 1-5 mg) support further evaluation of VPR in patients with UFs and heavy menstrual bleeding. STUDY FUNDING/COMPETING INTERESTS: This study was funded by Bayer Pharma AG. B.S., A.K., M.-H.S.M., C.S. and B.R. are employees of Bayer Pharma AG. B.S., A.K. and M.-H.S.M. are listed as inventors of an issued patent related to this work, and received payment for this from Bayer Pharma AG. D.B. is the founder of Biokinetic Europe Ltd, UK, which received funding for this study from Bayer Pharma AG. M.K. is an employee of Nuvisan GmbH, Germany, which received funding for this study from Bayer Pharma AG. TRIAL REGISTRATION NUMBER: Clinicaltrials.gov identifier: NCT01816815. TRIAL REGISTRATION DATE: 20 March 2013. DATE OF FIRST PATIENT'S ENROLMENT: 28 November 2011.

Mutations affecting the BHLHA9 DNA-binding domain cause MSSD, mesoaxial synostotic syndactyly with phalangeal reduction, Malik-Percin type.

Mesoaxial synostotic syndactyly, Malik-Percin type (MSSD) (syndactyly type IX) is a rare autosomal-recessive nonsyndromic digit anomaly with only two affected families reported so far. We previously showed that the trait is genetically distinct from other syndactyly types, and through autozygosity mapping we had identified a locus on chromosome 17p13.3 for this unique limb malformation. Here, we extend the number of independent pedigrees from various geographic regions segregating MSSD to a total of six. We demonstrate that three neighboring missense mutations affecting the highly conserved DNA-binding region of the basic helix-loop-helix A9 transcription factor (BHLHA9) are associated with this phenotype. Recombinant BHLHA9 generated by transient gene expression is shown to be located in the cytoplasm and the cell nucleus. Transcription factors 3, 4, and 12, members of the E protein (class I) family of helix-loop-helix transcription factors, are highlighted in yeast two-hybrid analysis as potential dimerization partners for BHLHA9. In the presence of BHLHA9, the potential of these three proteins to activate expression of an E-box-regulated target gene is reduced considerably. BHLHA9 harboring one of the three substitutions detected in MSSD-affected individuals eliminates entirely the transcription activation by these class I bHLH proteins. We conclude that by dimerizing with other bHLH protein monomers, BHLHA9 could fine tune the expression of regulatory factors governing determination of central limb mesenchyme cells, a function made impossible by altering critical amino acids in the DNA binding domain. These findings identify BHLHA9 as an essential player in the regulatory network governing limb morphogenesis in humans.

EE-drospirenone-levomefolate calcium versus EE-drospirenone + folic acid: folate status during 24 weeks of treatment and over 20 weeks following treatment cessation.

BACKGROUND: Adequate folate supplementation in the periconceptional phase is recommended to reduce the risk of neural tube defects. Oral contraceptives may provide a reasonable delivery vehicle for folate supplementation before conception in women of childbearing potential. This study aimed to demonstrate that a fixed-dose combination of an oral contraceptive and levomefolate calcium leads to sustainable improvements in folate status compared with an oral contraceptive + folic acid. METHODS: This was a double-blind, randomized, parallel-group study in which 172 healthy women aged 18-40 years received ethinylestradiol (EE)-drospirenone-levomefolate calcium or EE-drospirenone + folic acid for 24 weeks (invasion phase), and EE-drospirenone for an additional 20 weeks (folate elimination phase). The main objective of the invasion phase was to examine the area under the folate concentration time-curve for plasma and red blood cell (RBC) folate, while the main objective of the elimination phase was to determine the duration of time for which RBC folate concentration remained ≥ 906 nmol/L after cessation of EE-drospirenone-levomefolate calcium. RESULTS: Mean concentration-time curves for plasma folate, RBC folate, and homocysteine were comparable between treatment groups during both study phases. During the invasion phase, plasma and RBC folate concentrations increased and approached steady-state after about 8 weeks (plasma) or 24 weeks (RBC). After cessation of treatment with levomefolate calcium, folate concentrations decreased slowly. The median time to RBC folate concentrations falling below 906 nmol/L was 10 weeks (95% confidence interval 8-12 weeks) after cessation of EE-drospirenone-levomefolate calcium treatment. Plasma and RBC folate levels remained above baseline values in 41.3% and 89.3% of women, respectively, at the end of the 20-week elimination phase. CONCLUSION: Improvements in folate status were comparable between EE-drospirenone-levomefolate calcium and EE-drospirenone + folic acid. Plasma and RBC folate levels remained elevated for several months following cessation of treatment with EE-drospirenone-levomefolate calcium.

Effects of rifampicin on the pharmacokinetics of roflumilast and roflumilast N-oxide in healthy subjects.

AIMS: To evaluate the effect of co-administration of rifampicin, an inducer of cytochrome P450 (CYP)3A4, on the pharmacokinetics of roflumilast and roflumilast N-oxide. Roflumilast is an oral, once-daily phosphodiesterase 4 (PDE4) inhibitor, being developed for the treatment of chronic obstructive pulmonary disease. Roflumilast is metabolized by CYP3A4 and CYP1A2, with further involvement of CYP2C19 and extrahepatic CYP1A1. In vivo, roflumilast N-oxide contributes >90% to the total PDE4 inhibitory activity. METHODS: Sixteen healthy male subjects were enrolled in an open-label, three-period, fixed-sequence study. They received a single oral dose of roflumilast 500 microg on days 1 and 12 and repeated oral doses of rifampicin 600 mg once daily on days 5-15. Plasma concentrations of roflumilast and roflumilast N-oxide were measured for up to 96 h. Test/Reference ratios and 90% confidence intervals (CIs) of geometric means for AUC and C(max) of roflumilast and roflumilast N-oxide and for oral apparent clearance (CL/F) of roflumilast were estimated. RESULTS: During the steady-state of rifampicin, the AUC(0-infinity) of roflumilast decreased by 80% (point estimate 0.21; 90% CI 0.16, 0.27); C(max) by 68% (0.32; CI 0.26, 0.39); for roflumilast N-oxide, the AUC(0-infinity) decreased by 56% (0.44; CI 0.36, 0.55); C(max) increased by 30% (1.30; 1.15, 1.48); total PDE4 inhibitory activity decreased by 58% (0.42; 0.38, 0.48). CONCLUSIONS: Co-administration of rifampicin and roflumilast led to a reduction in total PDE4 inhibitory activity of roflumilast by about 58%. The use of potent cytochrome P450 inducers may reduce the therapeutic effect of roflumilast.

Fifth finger camptodactyly maps to chromosome 3q11.2-q13.12 in a large German kindred.

Camptodactyly (MIM 114200) is a digit deformity characterised by permanent flexion contracture of fifth fingers at the proximal interphalangeal (PIP) joints. The sporadic cases are common but a familial occurrence is not much appreciated. In an attempt to identify the genetic basis of camptodactyly, we have analysed a large German family with camptodactyly segregating in an autosomal dominant fashion. The affected family members exhibited clinical features of fifth finger camptodactyly and knuckle pads on the crooked fifth finger and on fingers 2-3. Typically, women were more severely affected than men. Microsatellite analyses of five candidate loci known to be associated with camptodactyly-like phenotypes did not show co-segregation with the phenotype in our family. A genome-wide linkage scan using a total of 414 microsatellite markers gave significant evidence of linkage between the familial phenotype and chromosomal locus 3q11.2-q13.12 (maximum two-point LOD score 3.04). The key recombination events showed that the phenotype localises between markers D3S2465 and D3S3044, spanning an interval of approximately 15 cM. This study reports the first genetic locus linked to isolated autosomal dominant fifth finger camptodactyly with knuckle pads and proves the hypothesis that camptodactyly is distinct from camptodactyly-associated phenotypes including Dupuytren contracture. Additional studies of other families will be necessary to determine the existence of genetic homogeneity or heterogeneity of the anomaly and to narrow down the genetic interval to identify the responsible gene. Since genetic heterogeneity for isolated camptodactyly is likely, we propose to designate the 3q11.2-q13.12 locus as CAMPD1 (ie, camptodactyly 1).

Synpolydactyly and HOXD13 polyalanine repeat: addition of 2 alanine residues is without clinical consequences.

BACKGROUND: Type II syndactyly or synpolydactyly (SPD) is clinically very heterogeneous, and genetically three distinct SPD conditions are known and have been designated as SPD1, SPD2 and SPD3, respectively. SPD1 type is associated with expansion mutations in HOXD13, resulting in an addition of > or = 7 alanine residues to the polyalanine repeat. It has been suggested that expansions < or = 6 alanine residues go without medical attention, as no such expansion has ever been reported with the SPD1 phenotype. METHODS: We describe a large Pakistani and an Indian family with SPD. We perform detailed clinical and molecular analyses to identify the genetic basis of this malformation. RESULTS: We have identified four distinct clinical categories for the SPD1 phenotype observed in the affected subjects in both families. Next, we show that a milder foot phenotype, previously described as a separate entity, is in fact a part of the SPD1 phenotypic spectrum. Then, we demonstrate that the phenotype in both families segregates with an identical expansion mutation of 21 bp in HOXD13. Finally, we show that the HOXD13 polyalanine repeat is polymorphic, and the expansion of 2 alanine residues, evident in unaffected subjects of both families, is without clinical consequences. CONCLUSION: It is the first molecular evidence supporting the hypothesis that expansion of < or = 6 alanine residues in the HOXD13 polyalanine repeat is not associated with the SPD1 phenotype.

Insulin: a model system for nanomedicine?

One of the predominant aims of insulin therapy for diabetes is to appropriately mimic physiological insulin secretion levels and their correlation with glucose concentration in healthy individuals. This report outlines current methods and their limitations in glycemic control and their possible relationship to insufficient knowledge about the structure and dynamics of the insulin hormone itself. Based on recent experimental and computational work, a possible approach to less-invasive insulin administration is sketched.

Evidence for clinical and genetic heterogeneity of syndactyly type I: the phenotype of second and third toe syndactyly maps to chromosome 3p21.31.

There is good evidence from the medical literature that type I syndactyly, the most common form of the nonsyndromic syndactylies, is clinically heterogeneous. We therefore propose to group the condition into four subtypes, which are all autosomal dominantly inherited. Subtype 1, zygodactyly (cutaneous webbing of second and third toe without hand involvement) is the mildest and most common form. The phenotype varies from unilateral minor impression of webbing to bilateral complete webbing of second and third toe including a fusion of nails. Bony involvement is never observed. Subtype 2 is characterized by bilateral cutaneous and/or bony webbing of third and fourth finger, and second and third toe. The phenotype maps on chromosome 2q34-q36 and was designated as SD1 (ie syndactyly 1). The hallmark of subtype 3 is bilateral cutaneous or bony webbing of third and fourth finger, while subtype 4 shows bilateral cutaneous webbing of fourth and fifth toe. Both, subtype 3 and 4, are rare entities. Here, we present clinical and molecular data of a large Pakistani family with zygodactyly that was mapped to a new locus on chromosome 3p21.31 by genome-wide linkage analysis. The highest LOD score (Zmax=3.38) was obtained with microsatellite marker D3S2409. The disease interval is flanked by markers Chr3_4919 and Chr3_4940 encompassing about 0.20 Mb. Since the same phenotype appears not to be linked to this locus in a German family, we predict genetic heterogeneity in zygodactyly and propose to designate the 3p21.31 locus as ZD1 (i.e., zygodactyly 1).

Autosomal recessive mesoaxial synostotic syndactyly with phalangeal reduction maps to chromosome 17p13.3.

Previously we have described a novel and distinct form of non-syndromic osseous syndactyly segregating in an autosomal recessive pattern in a consanguineous Pakistani family. The limb findings include mesoaxial reduction of the fingers, synostoses of the third and fourth metacarpals with associated single phalanges, fifth finger clinodactyly, and preaxial webbing of toes. We identified another published report of this phenotype in a large, inbred Turkish family. In the present study we mapped the phenotype in the Pakistani and Turkish families to chromosome 17p13.3 (multipoint LOD score 5.1). The identification of a single locus for this complex limb malformation in two families with distinct ethnic backgrounds supports the hypothesis that this is a distinct form of syndactyly. Since this form of syndactyly is phenotypically distinct from the previously described eight types, we propose to name this phenotype mesoaxial synostotic syndactyly with phalangeal reduction (MSSD, type IX syndactyly, Malik-Percin type).

Public, expert and patients' opinions on preimplantation genetic diagnosis (PGD) in Germany.

The regulation of reproductive medicine technologies differs significantly among Western industrialized countries. In Germany, preimplantation genetic diagnosis (PGD) is prohibited due to the Embryo Protection Act, which came into force in 1991. In the last 5 years, this prohibition has been vigorously debated. In the present studies, which are part of the German research programme on ethical implications of the Human Genome Project, representative surveys were undertaken to assess the attitudes on PGD in the general population (n = 1017), five relevant expert groups (n = 879), high genetic risk couples (n = 324) and couples undergoing IVF (n = 108). All groups surveyed clearly favoured allowing PGD in Germany. Compared with the results of recently conducted population surveys in the UK and the USA, where PGD is already carried out, public approval of PGD does not differ significantly. The influence of restrictive biopolitics on the apparently liberal public opinion towards new reproductive technology seems to be marginal according to the present data, which should carefully be considered in the ongoing legislation process on human reproduction.

A novel type of autosomal recessive syndactyly: clinical and molecular studies in a family of Pakistani origin.

Non-syndromic syndactylies have been classified into five major types (I-V), all showing autosomal dominant mode of inheritance. Later, the classification was extended and three additional variants (VI-VIII) were defined. Type VII, the Cenani-Lenz syndactyly, is the only non-syndromic, autosomal recessive type. It is characterized by fusion of all phalanges with metacarpal synostosis, dislocated and dysplastic carpals and infrequently, radio-ulnar fusion. Here, we present a Pakistani family with a novel non-syndromic autosomal recessive syndactyly manifesting a unique combination of clinical features. In both hands, reduction of certain phalanges is evident. Radiological examination shows synostosis of third and fourth metacarpals bearing single phalanges. The first three toes are webbed, with hypoplastic terminal phalanx in all the toes. Besides Cenani-Lenz syndactyly, the phenotype segregating in our family is the second well-documented autosomal recessive, non-syndromic syndactyly. A phenotype similar to our family was described in a Turkish kindred but was considered to be a homozygous expression of type I syndactyly. Since the clinical features in our family had minimal overlap with syndactyly types I, II, and III, we have performed microsatellite marker screening to look for the cosegregation of this phenotype with any of the known loci for these respective types. We show that the phenotype in our family is not linked to chromosomal regions 2q34-q36, 2q31, and 6q22-q23 encompassing loci for syndactyly types I, II, and III.

Muscle pathology in 57 patients with myotonic dystrophy type 2.

We evaluated muscle biopsies from 57 patients with genetically confirmed myotonic dystrophy type 2/proximal myotonic myopathy (DM2/PROMM). Light microscopy showed myopathic together with "denervation-like" changes in almost all biopsies obtained from four different muscles: increased fiber size variation, internal nuclei, small angulated fibers, pyknotic nuclear clumps, and predominant type 2 fiber atrophy. Quantitative morphometry in 18 biopsies that were immunostained for myosin heavy chain confirmed a predominance of nonselective type 2 fiber atrophy. These histological changes were similar in all patients regardless of the site of biopsy, the predominant clinical symptoms and signs, and the clinical course. It is likely that, in a number of undiagnosed patients, DM2 is the underlying disorder. With a better understanding of the histopathological pattern in DM2, biopsies from patients with undiagnosed neuromuscular disorders can now be reevaluated.

Facioscapulohumeral muscular dystrophy. Phenotype-genotype correlation in patients with borderline D4Z4 repeat numbers.

Facioscapulohumeral muscular dystrophy (FSHD) is associated with a decreased number of D4Z4 repeats on chromosome 4q35. Diagnostic difficulties arise from atypical clinical presentations and from an overlap in D4Z4 numbers between controls and FSHD individuals. Thus, a molecular genetic test result with a borderline D4Z4 number has its limitations for the clinician wanting to differentiate between the diagnosis of FSHD and a myopathy presenting with FSHD-like symptoms.To investigate this problem in more detail we conducted a systematic study of 39 unrelated FSHD patients with borderline D4Z4 repeat numbers and 102 healthy controls. Our aim was threefold: [1] to define the molecular diagnostic cut-off point between FSHD cases and the control population, [2] to describe the myopathic spectrum in patients with borderline D4Z4 repeat numbers and [3] to look for correlations between D4Z4 number and clinical severity. The results indicate that there is no definite D4Z4 diagnostic cut-off point separating FSHD, FSHD-like myopathies and controls. A broad myopathic spectrum with four phenotypes (typical FSHD, facial-sparing FSHD, FSHD with atypical features, non-FSHD muscle disease) was found in the borderline region. The expected correlation of D4Z4 repeat number and clinical severity was not found. Therefore the molecular test is of limited help to differentiate FSHD from FSHDlike muscle disorders when the D4Z4 number is n = >or= 8.

Evaluation of BMP4 and its specific inhibitor NOG as candidates in human neural tube defects (NTDs).

Neural tube defects (NTD) are among the most common congenital malformations in humans. The current view is that there are no major genes causing NTDs, but combinations of sequence variants in different genes have additive effects on determining the malformation. Therefore it is important to identify such sequence variants to get a better understanding of NTD pathogenesis. Studies on animal models have shown that BMP4 and NOG are involved in the patterning of the neural tube. We therefore performed a single-strand conformation analysis (SSCA) mutation screen for both genes in 179 spina bifida aperta (SBA) patients. Our SSCA screen revealed four missense mutations in BMP4 and one in NOG. It is likely that these mutations have acted together with other gene variants in independently segregating loci as susceptibility factors in these SBA cases. In addition, a case-control association study provides evidence for a genotype disequilibrium of BMP4 polymorphism 455T-->C (V152A) in exon 5. The frequency of the heterozygous 455TC genotype is lower in cases than in controls (nominal P=0.017), although allele frequencies are similar in both groups. A possible explanation for this finding might be that BMP4 455TC heterozygosity at this site is a protective factor in the normal population, although this hypothesis cannot be proven to date.

A polymorphic microsatellite that mediates induction of PIG3 by p53.

The gene PIG3 is induced by the tumor suppressor p53 but not by p53 mutants unable to induce apoptosis, suggesting its involvement in p53-mediated cell death. Here we show that p53 directly binds and activates the PIG3 promoter, but not through the previously described DNA element. Instead, p53 interacts with a pentanucleotide microsatellite sequence within the PIG3 promoter (TGYCC)n where Y=C or T. Despite its limited similarity to the p53-binding consensus, this sequence is necessary and sufficient for transcriptional activation of the PIG3 promoter by p53 and binds specifically to p53 in vitro and in vivo. In a population of 117 healthy donors from Germany, the microsatellite was found to be polymorphic, the number of pentanucleotide repeats being 10, 15, 16 or 17, and the frequency of alleles 5.1%, 62.0%, 21.4% and 11.5%, respectively. The number of repeats directly correlated with the extent of transcriptional activation by p53. This is the first time that a microsatellite has been shown to mediate the induction of a promoter through direct interaction with a transcription factor. Moreover, this sequence of PIG3 is the first p53-responsive element found to be polymorphic. Inheritance of this microsatellite may affect an individual's susceptibility to cancer.