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Introduction: The MYH7 c.5135G > A p.(Arg1712Gln) variant has been identified in several patients worldwide and is classified as pathogenic in the ClinVar database. We aimed to delineate its associated phenotype and evaluate a potential founder effect., Methods: We retrospectively collected clinical and genetic data of 22 probands and 74 family members from an international cohort., Results: In total, 53 individuals carried the MYH7 p.(Arg1712Gln) variant, of whom 38 (72%) were diagnosed with hypertrophic cardiomyopathy (HCM). Mean age at HCM diagnosis was 48.8 years (standard deviation: 18.1; range: 8-74). The clinical presentation ranged from asymptomatic HCM to arrhythmias (atrial fibrillation and malignant ventricular arrhythmias). Aborted sudden cardiac death (SCD) leading to the diagnosis of HCM occurred in one proband at the age of 68 years, and a family history of SCD was reported by 39% (5/13) probands. Neither heart failure deaths nor heart transplants were reported. Women had a generally later-onset disease, with 14% of female carriers diagnosed with HCM at age 50 years compared with 54% of male carriers. In both sexes, the disease was fully penetrant by age 75 years. Haplotypes were reconstructed for 35 patients and showed a founder effect in a subset of patients., Conclusion: MYH7 p.(Arg1712Gln) is a pathogenic founder variant with a consistent HCM phenotype that may present with delayed penetrance. This suggested that clinical follow-up should be pursued after the seventh decade in healthy carriers and that longer intervals between screening may be justified in healthy women < 30 years., (© 2023. The Author(s).)

Aim: To determine the prevalence of undiagnosed bicuspid aortic valve (BAV) and isolated aortic dilatation in first-degree relatives (FDRs) of patients with isolated BAV and to explore the recurrence risk of BAV in different subgroups of probands with BAV. Recent American College of Cardiology (ACC)/American Heart Association (AHA) Guidelines recommend family screening in patients with associated aortopathy only., Methods: During follow-up visits, patients with isolated BAV received a printed invitation for their FDRs advising cardiac screening., Results: From 2012-2019, 257 FDRs of 118 adult BAV patients were screened, among whom 63 (53%) index patients had undergone aortic valve surgery (AVS), including concomitant aortic replacement in 25 (21%). Of the non-operated index patients, 31 (26%) had aortic dilatation (> 40 mm). Mean age of the FDRs was 48 years (range 4-83) and 42% were male. The FDR group comprised 20 parents, 103 siblings and 134 offspring. Among these FDRs, 12 (4.7%) had a previously undiagnosed BAV and 23 (8.9%) had an isolated aortic dilatation. FDRs of the probands with previous AVS (n = 147) had a risk ratio for BAV of 2.25 (95% confidence interval (CI) 0.62-8.10). FDRs of the probands with BAV and repaired or unrepaired aortic dilatation (n = 127) had a risk ratio for BAV of 0.51 (95% CI 0.16-1.66)., Conclusion: Screening FDRs of patients with isolated BAV resulted in a reasonable yield of 14% new cases of BAV or isolated aortic dilatation. A trend towards an increased risk of BAV in FDRs was observed in the probands with previous AVS, whereas this risk seemed to be diminished in the probands with associated aortic dilatation. This latter finding does not support the restrictive ACC/AHA recommendation., (© 2021. The Author(s).)

Background: Idiopathic dilated cardiomyopathy (DCM) is recognised to be a heritable disorder, yet clinical genetic testing does not produce a diagnosis in >50% of paediatric patients. Identifying a genetic cause is crucial because this knowledge can affect management options, cardiac surveillance in relatives and reproductive decision-making. In this study, we sought to identify the underlying genetic defect in a patient born to consanguineous parents with rapidly progressive DCM that led to death in early infancy., Methods and Results: Exome sequencing revealed a potentially pathogenic, homozygous missense variant, c.542G>T, p.(Gly181Val), in SOD2 . This gene encodes superoxide dismutase 2 (SOD2) or manganese-superoxide dismutase, a mitochondrial matrix protein that scavenges oxygen radicals produced by oxidation-reduction and electron transport reactions occurring in mitochondria via conversion of superoxide anion (O 2 -· ) into H 2 O 2 . Measurement of hydroethidine oxidation showed a significant increase in O 2 -· levels in the patient's skin fibroblasts, as compared with controls, and this was paralleled by reduced catalytic activity of SOD2 in patient fibroblasts and muscle. Lentiviral complementation experiments demonstrated that mitochondrial SOD2 activity could be completely restored on transduction with wild type SOD2., Conclusion: Our results provide evidence that defective SOD2 may lead to toxic increases in the levels of damaging oxygen radicals in the neonatal heart, which can result in rapidly developing heart failure and death. We propose SOD2 as a novel nuclear-encoded mitochondrial protein involved in severe human neonatal cardiomyopathy, thus expanding the wide range of genetic factors involved in paediatric cardiomyopathies., Competing Interests: Competing interests: PHGMW is scientific advisor of Khondrion, Nijmegen, the Netherlands. This SME had no involvement in the data collection, analysis and interpretation, writing of the manuscript and in the decision to submit the manuscript for publication., (© Author(s) (or their employer(s)) 2020. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: Thoracic aortic aneurysms and dissections (TAAD) may have a heritable cause in up to 20% of cases. We aimed to investigate the pathogenic effect of a TGFBR1 mutation in relation to TAAD., Methods: Co-segregation analysis was performed followed by functional investigations, including myogenic transdifferentiation., Results: The c.1043G>A TGFBR1 mutation was found in the index patient, in a deceased brother, and in five presymptomatic family members. Evidence for pathogenicity was found by the predicted damaging effect of this mutation and the co-segregation in the family. Functional analysis with myogenic transdifferentiation of dermal fibroblasts to smooth muscle-like cells, revealed increased myogenic differentiation in patient cells with the TGFBR1 mutation, shown by a higher expression of myogenic markers ACTA2, MYH11 and CNN1 compared to cells from healthy controls., Conclusion: Our findings confirm the pathogenic effect of the TGFBR1 mutation in causing TAAD in Loeys-Dietz syndrome and show increased myogenic differentiation of patient fibroblasts., (© 2019 The Authors. Molecular Genetics & Genomic Medicine published by Wiley Periodicals, Inc.)

Background: Thoracic aortic aneurysm (TAA) is a potentially life-threatening disorder with a strong genetic component. The number of genes implicated in TAA has increased exponentially over the last decade. Approximately 20% of patients with TAA have a positive family history. As most TAA remain asymptomatic for a long time, screening of at risk relatives is warranted to prevent complications. Existing international guidelines lack detailed instructions regarding genetic evaluation and family screening of TAA patients. We aimed to develop a consensus document to provide medical guidance for all health care professionals involved in the recognition, diagnosis and treatment of patients with thoracic aortic disease and their relatives., Methods: A multidisciplinary panel of experts including cardiologists, cardiothoracic surgeons, clinical geneticists and general practitioners, convened to review and discuss the current literature, guidelines and clinical practice on genetic testing and family screening in TAA., Results: There is a lack of high-quality evidence in the literature. This consensus statement, based on the available literature and expert opinions, summarizes our recommendations in order to standardize and optimize the cardiogenetic care for patients and families with thoracic aortic disease. In particular, we provide criteria to identify those patients most likely to have a genetic predisposition, and discuss the preferred modality and frequency of screening in their relatives., Conclusions: Age, family history, aortic size and syndromic features determine who is advised to have genetic testing as well as screening of first-degree relatives. There is a need for more prospective multicenter studies to optimize current recommendations., (Copyright © 2018 The Authors. Published by Elsevier B.V. All rights reserved.)

Aim: To determine the prevalence of unidentified bicuspid aortic valve (BAV) or aortic dilatation (>40mm) in first degree relatives (FDR) of patients with isolated BAV in a general hospital., Methods and Results: Patients with isolated BAV received information advising cardiac screening of their FDR. Referred and screened were 134 FDR of 54 adult index patients with isolated BAV (median 2 per index patient). FDR's mean age was 49years (range 16-83years) and 41% were male. They comprised 5 parents (3.7%), 52 siblings (39%) and 77 offspring (57%). Among these FDR, the prevalence of BAV was 6.0% (8 patients). In FDR without BAV, 10 (7.5%) had aortic dilatation. 'Familial BAV' was present in 9/54 families (17%)., Conclusion: In a general hospital, screening of FDR of patients with isolated BAV resulted in a substantial yield of 13% new cases with BAV or aortic dilatation without BAV., (Copyright © 2017 Elsevier Ireland Ltd. All rights reserved.)

Introduction: The phenotype of Becker muscular dystrophy (BMD) is highly variable, and the disease may be underdiagnosed. We searched for new mutations in the DMD gene in a cohort of previously undiagnosed patients who had been referred in the period 1985-1995., Methods: All requests for DNA analysis of the DMD gene in probands with suspected BMD were re-evaluated. If the phenotype was compatible with BMD, and no deletions or duplications were detected, DNA samples were screened for small mutations., Results: In 79 of 185 referrals, no mutation was found. Analysis could be performed on 31 DNA samples. Seven different mutations, including 3 novel ones, were found. Long-term clinical follow-up is described., Conclusions: Refining DNA analysis in previously undiagnosed cases can identify mutations in the DMD gene and provide genetic diagnosis of BMD. A delayed diagnosis can still be valuable for the proband or the relatives of BMD patients., (© 2015 Wiley Periodicals, Inc.)

Background: Interpretation of genetic screening results in arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C) often is difficult. Pathogenicity of variants with uncertain clinical significance may be predicted by software algorithms. However, functional assessment can unambiguously demonstrate the effect of such variants., Objective: The purpose of this study was to perform functional analysis of potential splice site variants in ARVD/C patients., Methods: Nine variants in desmosomal (PKP2, JUP, DSG2, DSC2) genes with potential RNA splicing effect were analyzed. The variants were found in patients who fulfilled 2010 ARVD/C Task Force Criteria (n = 7) or had suspected ARVD/C (n = 2). Total RNA was isolated from fresh blood samples and subjected to reverse transcriptase polymerase chain reaction., Results: An effect on splicing was predicted by software algorithms for all variants. Of the 9 variants, 5 were intronic and 4 exonic. RNA analysis showed a functional effect on mRNA splicing by exon skipping, generation of new splice sites, or activation of cryptic sites in 6 variants. All 5 intronic variants tested severely impaired splicing. Only 1 of 4 exonic potential splice site variants was shown to have a deleterious effect on splicing. The remaining 3 exonic variants had no detectable effect on splicing, and heterozygous presence in mRNA confirmed biallelic expression., Conclusion: Six variants of uncertain clinical significance in the PKP2, JUP, and DSG2 genes showed a deleterious effect on mRNA splicing, indicating these are ARVD/C-related pathogenic splice site mutations. These results highlight the importance of functional assessment of potential splice site variants to improve patient care and facilitate cascade screening., (Copyright © 2014 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.)

Background: The pathogenic phospholamban R14del mutation causes dilated and arrhythmogenic right ventricular cardiomyopathies and is associated with an increased risk of malignant ventricular arrhythmias and end-stage heart failure. We performed a multicentre study to evaluate mortality, cardiac disease outcome, and risk factors for malignant ventricular arrhythmias in a cohort of phospholamban R14del mutation carriers., Methods and Results: Using the family tree mortality ratio method in a cohort of 403 phospholamban R14del mutation carriers, we found a standardized mortality ratio of 1.7 (95% confidence interval, 1.4-2.0) with significant excess mortality starting from the age of 25 years. Cardiological data were available for 295 carriers. In a median follow-up period of 42 months, 55 (19%) individuals had a first episode of malignant ventricular arrhythmias and 33 (11%) had an end-stage heart failure event. The youngest age at which a malignant ventricular arrhythmia occurred was 20 years, whereas for an end-stage heart failure event this was 31 years. Independent risk factors for malignant ventricular arrhythmias were left ventricular ejection fraction <45% and sustained or nonsustained ventricular tachycardia with hazard ratios of 4.0 (95% confidence interval, 1.9-8.1) and 2.6 (95% confidence interval, 1.5-4.5), respectively., Conclusions: Phospholamban R14del mutation carriers are at high risk for malignant ventricular arrhythmias and end-stage heart failure, with left ventricular ejection fraction <45% and sustained or nonsustained ventricular tachycardia as independent risk factors. High mortality and a poor prognosis are present from late adolescence. Genetic and cardiac screening is, therefore, advised from adolescence onwards., (© 2014 American Heart Association, Inc.)

Patients with myelodysplastic syndromes (MDS) often show elevated serum ferritin levels at diagnosis, probably caused by increased intestinal iron uptake attributable to ineffective erythropoiesis. Many patients also develop transfusional iron overload. Hepcidin, a pivotal regulator of iron homeostasis, controls iron uptake in the duodenum as well as iron release from macrophages and is potentially involved in iron distribution to different organs. We measured serum hepcidin, together with other laboratory parameters related to iron metabolism and hematopoiesis (ferritin, transferrin, transferrin saturation, soluble transferrin receptor, erythropoietin, and hemoglobin), and C-reactive protein as marker of inflammation, in 89 MDS patients. Hepcidin levels were measured with two different competitive ELISAs: (a) EIA-4705 as described by Schwarz et al. (J Gastroenterol 46:648-656; 2011) and (b) Hepcidin 25 bioactive ELISA (EIA-5258), which was develop by DRG Diagnostics, Marburg, in 2012. Median hepcidin levels with EIA-5258 were as follows: entire cohort 17.5 ng/ml (n = 89), RA/RARS 5.9 ng/ml (n = 5), RCMD 17.8 ng/ml (n = 38), RS-RCMD 8.7 ng/ml (n = 7), RAEB I/II 29.1 ng/ml (n = 22), CMML I/II 16.9 ng/ml (n = 10), and MDS with del(5q) 26.3 ng/ml (n = 7). Hepcidin levels of the RA/RARS patients were significantly lower than in the other groups except RS-RCMD. RS-RCMD had significantly lower levels than RAEB and 5q- patients. There was a positive correlation between hepcidin levels and serum ferritin and transferrin saturation, and a negative correlation between hepcidin and hemoglobin and transferrin. Malcovati et al. (Blood 112:2676a, 2008), Santini et al. (PLoS One 6:e23109, 2011), and Ambaglio et al. (Haematologica 98:420-423, 2013), using mass spectrometry, reported similar results. We further assessed transfusional status and could show that patients who had been transfused have significantly higher hepcidin levels (median 33.3 versus 8.8 ng/ml (p < 0.001)). A dichotomized hepcidin level correlated with worse survival. EIA-4705 as described by Schwarz showed no correlation with markers of iron metabolism. Measurement of serum hepcidin with an improved ELISA yield results that correlate with other parameters of iron metabolism as well as survival and transfusion needs.

Aims: With more than 40 dilated cardiomyopathy (DCM)-related genes known, genetic analysis of patients with idiopathic DCM is costly and time-consuming. We describe the yield from genetic analysis in DCM patients in a large Dutch cohort., Methods and Results: We collected cardiological and neurological evaluations, family screenings, and genetic analyses for 418 index patients with idiopathic DCM. We identified 35 (putative) pathogenic mutations in 82 index patients (20%). The type of DCM influenced the yield, with mutations found in 25% of familial DCM cases, compared with 8% of sporadic DCM cases and 62% of cases where DCM was accompanied by neuromuscular disease. A PLN founder mutation (43 cases) and LMNA mutations (19 cases, 16 different mutations) were most prevalent and often demonstrated a specific phenotype. Other mutations were found in: MYH7, DES, TNNT2, DMD, TPM1, DMPK, SCN5A, SGCB (homozygous), and TNNI3. After a median follow-up of 40 months, the combined outcome of death from any cause, heart transplantation, or malignant ventricular arrhythmias in patients with a mutation was worse than in those without an identified mutation (hazard ratio 2.0, 95% confidence interval 1.4-3.0). This seems to be mainly attributable to a high prevalence of malignant ventricular arrhythmias and end-stage heart failure in LMNA and PLN mutation carriers., Conclusion: The yield of identified mutations in DCM index patients with clinical clues, such as associated neuromuscular disease or familial occurrence, is higher compared with those without these clues. For sporadic DCM, specific clinical characteristics may be used to select cases for DNA analysis.

Background: Recently, we showed that the c.40&#95;42delAGA (p.Arg14del) mutation in the phospholamban (PLN) gene can be identified in 10-15 % of Dutch patients with dilated cardiomyopathy or arrhythmogenic cardiomyopathy. The arrhythmogenic burden of the p.Arg14del mutation was illustrated by the high rate of appropriate ICD discharges and a positive family history for sudden cardiac death., Methods: Our goal was to evaluate the geographical distribution and the origin of this specific mutation in the Netherlands and to get an estimation of the prevalence in a Dutch population cohort. Therefore, we investigated the postal codes of the places of residence of PLN p.Arg14del mutation carriers and places of birth of their ancestors. In addition, a large population-based cohort (PREVEND) was screened for the presence of this mutation., Results: By April 2012, we had identified 101 probands carrying the PLN p.Arg14del mutation. A total of 358 family members were also found to carry this mutation, resulting in a total of 459 mutation carriers. The majority of mutation carriers live in the northern part of the Netherlands and analysing their grandparents' places of birth indicated that the mutation likely originated in the eastern part of the province of Friesland. In the PREVEND cohort we identified six heterozygous PLN p.Arg14del mutation carriers out of 8,267 subjects (0.07 %)., Conclusion: The p.Arg14del mutation in the PLN gene is the most frequently identified mutation in Dutch cardiomyopathy patients. The mutation that arose 575-825 years ago is likely to have originated from the eastern part of the province of Friesland and is highly prevalent in the general population in the northern part of the Netherlands.

Heterozygous fumarate hydratase (FH) germline mutations cause hereditary leiomyomatosis and renal cell cancer (HLRCC), an autosomal dominant syndrome characterized by multiple cutaneous piloleiomyomas, uterine leiomyomas and papillary type 2 renal cancer. The main objective of our study was to evaluate clinical and genetic data from families suspected of HLRCC on a nationwide level. All families referred for FH mutation analysis in the Netherlands were assessed. We performed FH sequence analysis and multiplex ligation-dependent probe amplification. Families with similar FH mutations were examined for haplotype sharing. In 14 out of 33 families, we identified 11 different pathogenic FH germline mutations, including 4 novel mutations and 1 whole-gene deletion. Clinical data were available for 35 FH mutation carriers. Cutaneous leiomyomas were present in all FH mutation carriers older than 40 years of age. Eleven out of 21 female FH mutation carriers underwent surgical treatment for symptomatic uterine leiomyomas at an average of 35 years. Two FH mutation carriers had papillary type 2 renal cancer and Wilms' tumour, respectively. We evaluated the relevance of our findings for clinical practice and have proposed clinical diagnostic criteria, indications for FH mutation analysis and recommendations for management., (© 2010 John Wiley & Sons A/S.)

Background: Loeys-Dietz syndrome (LDS) is a newly recognised disorder of connective tissue which shares overlapping features with Marfan syndrome (MFS) and the vascular type of Ehlers-Danlos syndrome, including aortic root dilatation and skin abnormalities. It is clinically classified into types 1 and 2. LDS type 1 can be recognised by craniofacial characteristics, e.g. hypertelorism, bifid uvula or cleft palate, whereas these are absent in LDS type 2. It is important to recognise LDS because its vascular pathology is aggressive. We describe nine LDS patients from four families, relate their features to published cases, and discuss important aspects of the diagnosis and management of LDS in order to make clinicians aware of this new syndrome., Results: Characteristics found in the majority of these LDS patients were aortic root dilatation, cleft palate and/or a bifid/abnormal uvula., Conclusion: Because aortic dissection and rupture in LDS tend to occur at a young age or at aortic root diameters not considered at risk in MFS, and because the vascular pathology can be seen throughout the entire arterial tree, patients should be carefully followed up and aggressive surgical treatment is mandatory. Clinicians must therefore be aware of LDS as a cause of aggressive aortic pathology and that its distinguishing features can sometimes be easily recognised. (Neth Heart J 2008;16:299-304.).

Quantitative Risk Assessment (QRA) is a method which is often used in the chemical industry and, in some countries, also in land-use planning. In QRA calculations the frequency of an accident scenario is most often assessed by a generic failure frequency approach. The credibility and validity of the failure frequencies used in the Netherlands for land-use planning is evaluated by means of an historical review. Furthermore, the possibility is presented how these generic data can be revised and updated.

Multiple endocrine neoplasia type 1 (MEN1) is an inherited syndrome that is characterised by the occurrence of tumours in the parathyroid glands, the endocrine pancreas, the pituitary gland and the adrenal glands and by neuroendocrine carcinoid tumours, often at a young age. The penetrance of MEN1 among gene carriers is reported to be high; 82-99% at age 50. We present a patient with a history of parathyroid adenomas also showing signs of acromegaly. He turned out to be a carrier of a MEN1 germ-line mutation in intron 3 (IVS3-6C > G). This germ-line mutation was also found in nine of his family members. However, none of these relatives have developed any MEN1-related lesion yet, although several are older than 60 years. To our knowledge, a MEN1 family with as few clinical features as this family has not been reported to date. Because MEN1 patients have an increased risk of developing acromegaly, insulin-like growth factor (IGF-I) levels are monitored periodically. We investigated whether IGF-I levels might serve as a presymptomatic marker for acromegaly; 9% (3/33) of MEN1 patients showed temporary IGF-I elevations. One patient (1/3) later developed clinical signs of acromegaly. Possibly, acromegaly in MEN1 is preceded by a transient preacromegalic state.

Background & Aims: Germline mutations in one of four mismatch repair genes have been found in the majority of families with hereditary nonpolyposis colorectal cancer (HNPCC), but only in a small part of families with atypical HNPCC. The recently cloned EXO1 gene might be involved in the pathogenesis of HNPCC because the EXO1 protein strongly interacts with the MSH2 protein. To determine its role in HNPCC, EXO1 was scanned for germline mutations., Methods: All 14 exons of EXO1 were scanned for mutations in index patients from 33 families with HNPCC fulfilling the Amsterdam criteria and in 225 index patients suspected of HNPCC., Results: Germline variants of EXO1 were detected in 14 patients, including one splice-site mutation in a family with HNPCC and 13 missense mutations in patients with atypical HNPCC. These variants did not occur in more than 200 control individuals. From 13 of these 14 patients, tumors were available for analysis of microsatellite instability and loss of heterozygosity. Six of the tumors showed microsatellite instability. Heterozygosity analysis showed one case without EXO1 allelic loss and 12 tumors with loss of the mutant allele and retention of the normal one., Conclusions: The results indicate a possible association of germline EXO1 variants with HNPCC and atypical HNPCC.

In the Netherlands, the individual risk and the societal risk are used in efforts to reduce the number of people exposed to the effects of an accident. In principle, the societal risk for each new land-use plan should be recalculated. Since this is proving increasingly cumbersome for planning agencies, several methods have been developed for SEVESO establishments and establishments for which in the Netherlands a generic zoning policy is used to determine the effects of new land-use plans on the societal risk. The methods give the uniform population density from a certain distance around the establishment at which the indicative limit for the societal risk is not exceeded. Correction factors are determined for non-uniform population distributions around the establishment, non-continuous residence times and deviating societal risk limits. Using these methods allows decision-making without the necessity of repeating quantified risk analyses for each alternative proposal.

The assessment of risks to the aquatic environment related to industrial installations is a priority in environmental pollution control in the Netherlands. Major accidents to the surface water such as the Sandoz incident, but also the high number of smaller accidents that occur every year has invoked the need for an effective method to assess these risks. Two different models have been used in this field in the Netherlands over several years. These two software applications, VERIS and RISAM were developed from two different perspectives: VERIS from the perspective of supplying major accidents related information in the safety report, RISAM form the perspective of controlling risks for both smaller and larger facilities that may pollute surface waters through accidents. Both systems comprised particular strong points: VERIS considers safety management aspects in the assessment, RISAM considers differences in surface water vulnerability and involves quantitative probabilities in the assessment. It was decided to integrate both methods and maintain these strong points in the resulting method. This paper describes the new integrated risk assessment method that now has been developed in a concerted effort between the Ministry of Transport, Public Works and Water Management, the Ministry of Housing, Spatial Planning and Environment, and the National Institute for Public Health and Environment. It also describes the essential elements of the computer program PROTEUS that is based on the new method and that makes the assessment of aquatic risks for industrial activities an easy task, partly due to the automatic generation of the assessment report.

Middle-aged patients who initially present with a progressive cerebellar ataxia, in the absence of a known familial pattern are often referred to under the descriptive diagnosis of 'idiopathic' late onset cerebellar ataxia. If these patients in time develop additional pyramidal or extrapyramidal features then they should be labeled as olivopontocerebellar atrophy (sOPCA). This case report describes a patient with OPCA with cerebellar ataxia as the presenting and most prominent feature in combination with dementia, pyramidal signs, cortical cataract of the posterior pole and a raised IgG index in cerebrospinal fluid. To the best of our knowledge this combination of signs and symptoms have not been described before.

The influence of type of photosensitizer, drug and light dose, and time interval between photosensitizer and illumination on the extent of photodynamic therapy (PDT)-induced bladder damage and recovery was investigated using a mouse model. The three photosensitizers studied were Photofrin, meso-tetrahydroxyphenylchlorin (m-THPC) and bacteriochlorin a (BCA). Functional bladder damage was quantitatively assessed from increases in urination frequency index (FI) at 1-35 weeks after illumination and histological damage was qualitatively assessed at 1 day, 1, 2 and 12 weeks. Photofrin-mediated PDT caused an acute increase in FI at 1 week, with recovery within 2-8 weeks after light doses of 2.7-8.2 J/cm2. After higher light doses there was only partial recovery. Previous results indicated that the acute response and rate of recovery was the same whether Photofrin was given at 1 day or up to 7 days before illumination. The m-THPC-mediated PDT at drug doses of > or = 0.3 mg/kg also resulted in a marked acute response with good recovery, even after 10.8 J/cm2. Lower drug doses in combination with 5.4 J/cm2 did not result in acute or late damage. There was no significant difference in acute response when m-THPC was given 1, 3 or 7 days before illumination, although recovery was faster for the longer illumination intervals (3 or 7 days). Illumination at 1 h after 20 mg/kg BCA induced an acute response within 2 days after illumination, with recovery within 4-8 weeks. Lower drug doses did not result in damage. The most prominent histological changes during the acute period with all three photosensitizers were submucosal edema and vessel dilation, with epithelial denudation (depending on drug/light dose). We conclude that BCA and m-THPC are both potent new photosensitizers. They can induce a moderate to severe acute bladder response with complete healing over a period of a few weeks. The photosensitizer m-THPC is very effective with low doses of photosensitizer and light, whereas relatively high doses of BCA and light are required to obtain equivalent functional bladder damage in our mouse model.

The aim of this project was to measure the irradiation tolerance of normal (non tumour bearing) mouse bladder after previous intravesical photodynamic therapy (PDT). Illumination with a range of light doses at 24 h after Photofrin was used as the initial PDT treatment and irradiation with a range of X-ray doses was given at 12 or 24 weeks after the initial therapy. Functional bladder damage was assessed from changes in micturition frequency (tested regularly for a follow-up period of 53 weeks after irradiation) and from cystometry measurements of the bladder at 53-56 weeks. PDT alone caused a marked increase in micturition frequency, with (partial) recovery by the time of irradiation. Irradiation alone caused a modest, transient acute response within 5 weeks and a progressive, permanent late response starting from about 25 weeks depending on X-ray dose. A reduced bladder capacity was also evident at 53-56 weeks after 20 Gy X-rays and after PDT alone. Irradiation after previous intravesical PDT caused an acute reaction similar to X-rays alone, but there was a much earlier expression of late functional bladder damage. The final level of damage prior to sacrifice at 53-56 weeks, was not significantly greater than after X-rays alone. These results suggest that irradiation after previous whole bladder PDT, for refractory bladder tumours, may lead to an increased risk of persistent increases in micturition frequency and reduced bladder capacity, beginning at very early times after irradiation.

Batten disease, or the juvenile form of neuronal ceroid lipofuscinosis, is an autosomal recessive neurodegenerative disorder manifesting with progressive blindness, seizures, and dementia, leading to an early death. The CLN3 locus which is involved in Batten disease had been localized to chromosome 16p11.2. Linkage disequilibrium has been observed between CLN3 and polymorphic microsatellite markers D16S288, D16S299, and D16S298, making carrier detection and prenatal diagnosis by haplotype analysis possible. For the purpose of carrier detection, haplotypes from Dutch Batten patients and their families were constructed. Most patients share the same D16S298 allele, suggesting the presence of a founder effect in the Dutch population. In a large inbred Dutch family, in which Batten disease occurs with high frequency, haplotype analysis has been carried out with high accuracy for carrier detection.

The aim of this study was to compare functional damage in normal mouse bladder after various initial intravesical therapies and to investigate tolerance to subsequent irradiation. Six consecutive weekly intravesical instillations of Mitomycin C (MMC) or doxorubicin (DOX) were used as the initial therapy. Irradiation with single doses of 10-25 Gy (X-rays) was given at 4 or 12 weeks after intravesical treatment. Functional bladder damage was assessed from changes in the micturition frequency, expressed as frequency index (FI, number of urination events/ml urine in a 24-h test period) and from cystometry measurements of bladder volume at 52-56 weeks. Irradiation alone caused a temporary acute response (increased FI) within the first 4 weeks and a progressive late response starting from 15 to 37 weeks, depending on the radiation dose. A reduced bladder capacity was also evident at 52-56 weeks after 25 Gy. Intravesical MMC or DOX caused a 3-fold increase in FI during intravesical therapy with recovery to control levels within 2-3 weeks after cessation of treatment. Irradiation 4 weeks after MMC, or 4 or 12 weeks after DOX resulted in acute responses very similar to irradiation alone. There was no difference in time of onset or extent of late bladder damage when irradiation was given after DOX, compared with irradiation alone as assessed from repeated measurements of FI or cystometry at 52-56 weeks. In contrast, irradiation 12 weeks after MMC led to a decrease in acute radiation response compared with X-rays alone.(ABSTRACT TRUNCATED AT 250 WORDS)

Functional and histological damage after intravesical administration of mitomycin C or doxorubicin were studied in mouse bladders. Dosing schedules were based on those commonly used in the clinic, and bladder function was assessed from changes in urination frequency. Repeated weekly instillations of 1 mg./ml. mitomycin C induced a transient three-fold increase in Frequency Index (FI) with recovery to control levels within 3 weeks. Weekly instillations of 6 mg./ml. doxorubicin also resulted in a three-fold increase in FI, but lower doses produced only minimal changes. There was, again, full recovery within 3 weeks. Our experiments indicate that repeated intravesical instillations of mitomycin C or doxorubicin are well tolerated, with rapid recovery from functional damage within a few weeks of cessation of therapy. There was significantly less damage after repeated instillations of clinically relevant doses of doxorubicin than mitomycin C.

Fragile X (fra(X)) syndrome, the most common form of familial mental retardation, is caused by heritable unstable DNA composed of CGG repeats. As reproductive fitness of fra(X) patients is severely compromised, a high mutation rate has been proposed to explain the high prevalence. However, we have been unable to show any new mutation for 84 probands referred to us to date. We show here the same fra(X) gene in five fra(X) probands with common ancestors married in 1747. The lack of new fra(X) mutations implies that there must be many more fra(X) gene carriers in the population than previously realised. As it is now possible to detect asymptomatic fra(X) gene carriers by DNA analysis, extended family studies for any new proband are recommended. A family illustrating the importance of fra(X) carriership determination is reported.

Two cases with trisomy 16 confined to the placenta are presented. Prenatal diagnosis was indicated because of fetal growth retardation. In case 1, a phenotypically normal but small-for-date boy was born. In case 2, the fetus turned out to be triploid on cordocentesis. In both instances the trisomy 16 was recovered from the placenta. Recovery indicates that the abnormality was present in the placenta during the time of fetal growth retardation, which supports an aetiological relationship. Strict appliance of the current models cannot readily explain the observed discrepancies. In case 2, a chimeric placenta as a result of a vanishing twin is assumed. Cases of placental trisomy 16 published after 1988 are reviewed. It is concluded that confined placental trisomy 16 can cause intrauterine growth retardation if present in both the direct preparation and the villus culture. The chances of finding a chromosomally abnormal fetus (mosaic trisomy 16, triploidy) after diagnosis of trisomy 16 in chorionic villi are low but warrant further investigations.

The genotoxic activity of benzo[a]pyrene (BAP), 2-nitrofluorene (NF) and airborne particulate matter was evaluated in the DNA-repair host-mediated assay after intraperitoneal or intratracheal administration. Dimethylnitrosamine (DMNA), used as a positive control, showed a genotoxic effect after both intraperitoneal and intratracheal administration, the strongest effect being found in liver, followed by lungs and kidneys, whereas a weak effect was observed in the spleen. In general no difference in genotoxicity was found between the 2 administration routes used. For BAP, although clearly positive in vitro, a moderate dose-dependent effect was found only in the liver after intraperitoneal administration. NF, which was positive in vitro both with and without a metabolizing system, produced no genotoxic effect in any of the organs tested after intraperitoneal administration. Extracts of airborne particulate matter which were genotoxic in vitro failed to cause a genotoxic effect in vivo by either route of administration. Possible explanations for the differences between the data obtained in vitro and in vivo are discussed.

After orthotopic liver transplantation (OLT), not infrequently a deterioration of bone disease leading to compression fractures of vertebrae is seen. In a consecutive series of 36 adult OLT patients, we studied, clinically and radiologically, the incidence and degree of bone disease before and after OLT; we also studied whether clinical, radiological and laboratory findings were related to the event of postoperative vertebral collapse. Before OLT, radiological signs of mostly slight osteoporosis were seen in a minority of patients. After OLT, 38% of patients developed vertebral collapse, mainly in the second trimester. Collapse occurred in both previously normal and abnormal vertebrae. Of the preoperative parameters sex, age, menopause, intake of prednisolone, duration and diagnosis of liver disease, duration and degree of cholestasis, bone radiology and urinary calcium, only a low urinary calcium was related to postoperative collapse. Of the postoperative parameters duration of cholestasis, urinary calcium, duration of hospital stay, prednisolone dose and outcome in terms of life and death, none was related to collapse. We conclude that vertebral collapse after OLT occurs frequently and is not easily predicted. Early prevention of bone disease in patients with chronic liver disease before OLT and a low steroid-containing immunosuppressive regimen after OLT are advocated.