Evolution of genome diagnostics in epidermolysis bullosa: Unveiling the power of next-generation sequencing.

BACKGROUND: Genome diagnostics is considered gold standard diagnostics for epidermolysis bullosa (EB), a phenotypically and genetically heterogeneous group of rare disorders characterized by blistering and wounding of mucocutaneous tissues. EB is caused by pathogenic variants in genes encoding proteins of the dermo-epidermal junction. Accurate genetic diagnosis of EB is crucial for prognostication, counselling and precision-medicine. Genome diagnostics for EB started in 1991 with the introduction of Sanger sequencing (SS), analysing one gene at a time. In 2013, SS was superseded by next-generation sequencing (NGS), that allow for high-throughput sequencing of multiple genes in parallel. Several studies have shown a beneficial role for NGS in EB diagnostics, but its true benefit has not been quantified. OBJECTIVES: To determine the benefit of NGS in EB by systematically evaluating the performance of different genome diagnostics used over time based on robust data from the Dutch EB Registry. METHODS: The diagnostic performances of SS and NGS were systematically evaluated in a retrospective observational study including all index cases with a clinical diagnosis of EB in whom genome diagnostics was performed between 01 January 1994 and 01 January 2022 (n = 308), registered at the Dutch EB Expertise Centre. RESULTS: Over time, a genetic diagnosis was made in 289/308 (94%) EB cases. The diagnostic yield increased from 89% (SS) to 95% (NGS). Most importantly, NGS significantly reduced diagnostic turnaround time (39 days vs. 211 days, p < 0.001). The likelihood of detecting variants of uncertain significance and additional findings increased from 5% and 1% (SS) to 22% and 13% (NGS) respectively. CONCLUSIONS: Our study quantifies the benefit of NGS-based methods and demonstrate they have had a major impact on EB diagnostics through an increased diagnostic yield and a dramatically decreased turnaround time (39 days). Although our diagnostic yield is high (95%), further improvement of genome diagnostics is urgently needed to provide a genetic diagnosis in all EB patients.

Exocrine pancreatic and enterocyte function in patients with advanced pancreatic cancer.

BACKGROUND & AIMS: Exocrine pancreatic function is affected in patients with locally advanced pancreatic cancer (LAPC), clinically leading to steatorrhea. It is unknown whether maldigestion and malabsorption can also be attributed to impaired intestinal enterocyte function. In this exploratory study enterocyte function was assessed in patients with locally advanced pancreatic cancer, treated with Irreversible Electroporation (IRE). METHODS: Enterocyte function was studied by Citrulline Generation Test (CGT). Intestinal absorption capacity of energy and fat was calculated from the differences between nutritional intake (four-days diary) and quantified fecal losses energy and fat in three-days feces collection. RESULTS: Twelve patients were included before IRE, and 5 patients had follow-up measurements. Fasted citrulline [CIT] and glutamine [GLU] levels were below reference levels of healthy subjects ([CIT] 38 ± 8 µmol/L; [GLU] 561 ± 77 µmol/L) both before ([CIT] 25 ± 9 µmol/L; [GLU] 65 ± 35 µmol/L) and after IRE ([CIT] 19 ± 9 µmol/L; [GLU] 53 ± 26 µmol/L) whereas CGT curves were normal, indicating normal enterocyte function (slope 0.21 ± 0.12 and 0.17 ± 0.07 µmol/L/min; [CIT] increment 63 ± 39 and 80 ± 44% respectively). Severe energy/fat malabsorption was present in 6 out of 12 patients with LAPC (mean loss 349 kcal/d, 13 g fat/d) before and in 4 out of 5 patients (mean loss 509 kcal/d, 32 g fat/d) after IRE respectively. CONCLUSIONS: Enterocyte function was generally within reference limits in patients with advanced pancreatic cancer. Severe malabsorption may be explained by exocrine pancreatic insufficiency.

Irreversible Electroporation in Hepatopancreaticobiliary Tumours.

Hepatopancreaticobiliary tumours are often diagnosed at an advanced disease stage, in which encasement or invasion of local biliary or vascular structures has already occurred. Irreversible electroporation (IRE) is an image-guided tumour ablation technique that induces cell death by exposing the tumour to high-voltage electrical pulses. The cellular membrane is disrupted, while sparing the extracellular matrix of critical tubular structures. The preservation of tissue integrity makes IRE an attractive treatment option for tumours in the vicinity of vital structures such as splanchnic blood vessels and major bile ducts. This article reviews current data and discusses future trends of IRE for hepatopancreaticobiliary tumours.

The glutathione transferase Mu null genotype leads to lower 6-MMPR levels in patients treated with azathioprine but not with mercaptopurine.

The conversion of azathioprine (AZA) to mercaptopurine (MP) is mediated by glutathione transferase Mu1 (GSTM1), alpha1 (GSTA1) and alpha2 (GSTA2). We designed a case-control study with data from the TOPIC trial to explore the effects of genetic variation on steady state 6-methylmercaptopurine ribonucleotide (6-MMPR) and 6-thioguanine nucleotide (6-TGN) metabolite levels. We included 199 patients with inflammatory bowel disease (126 on AZA and 73 on MP). GSTM1-null genotype carriers on AZA had two-fold lower 6-MMPR levels than AZA users carrying one or two copies of GSTM1 (2239 (1006-4587) versus 4371 (1897-7369) pmol/8 × 108 RBCs; P<0.01). In patients on MP (control group) 6-MMPR levels were comparable (6195 (1551-10712) versus 6544 (1717-11600) pmol/8 × 108 RBCs; P=0.84). The 6-TGN levels were not affected by the GSTM1 genotype. The presence of genetic variants in GSTA1 and GSTA2 was not related to the 6-MMPR and 6-TGN levels.

Assessment of Nutritional Status, Digestion and Absorption, and Quality of Life in Patients with Locally Advanced Pancreatic Cancer.

BACKGROUND AND AIM: To provide a comprehensive quantitative assessment of nutritional status, digestion and absorption, and quality of life (QoL) in patients with locally advanced pancreatic cancer (LAPC). METHODS: Sixteen patients with LAPC were prospectively assessed for weight loss (WL), body mass index (BMI), fat-free mass index (FFMI), handgrip strength (HGS), dietary macronutrient intake, serum vitamin levels, resting and total energy expenditure (REE and TEE, indirect calorimetry), intestinal absorption capacity and fecal losses (bomb calorimetry), exocrine pancreatic function (fecal elastase-1 (FE1)), and gastrointestinal quality of life (GIQLI). RESULTS: Two patients had a low BMI, 10 patients had WL > 10%/6 months, 8 patients had a FFMI < P10, and 8 patients had a HGS < P10. Measured REE was 33% higher (P = 0.002) than predicted REE. TEE was significantly higher than daily energy intake (P = 0.047). Malabsorption (<85%) of energy, fat, protein, and carbohydrates was observed in, respectively, 9, 8, 12, and 10 patients. FE1 levels were low (<200 µg/g) in 13 patients. Total QoL scored 71% (ample satisfactory). CONCLUSION: Patients with LAPC have a severely impaired nutritional status, most likely as a result of an increased REE and malabsorption due to exocrine pancreatic insufficiency. The trial is registered with PANFIRE clinicaltrials.gov NCT01939665.

Risk factors for thiopurine-induced myelosuppression and infections in inflammatory bowel disease patients with a normal TPMT genotype.

BACKGROUND: Leucopenia is a common side effect in patients treated with thiopurines. Variants in the thiopurine S-methyltransferase (TPMT) gene are the best-known risk factor, but only explain up to 25% of leucopenia cases. AIM: To identify the clinical risk factors for thiopurine-induced leucopenia in patients without a common TPMT variant, and explore if these patients are at increased risk for infections. METHODS: Post hoc analysis of the Thiopurine response Optimisation by Pharmacogenetic testing in Inflammatory bowel disease Clinics (TOPIC) trial. For this analysis, patients without a variant in TPMT (*2, *3A or*3C) were included. Uni- and multivariate Cox-proportional hazard models were used to identify risk factors for leucopenia and infections. Leucopenia was defined as a white blood cell (WBC) count <3.0 × 109 /L and infections were classified according to the Common Terminology Criteria for Adverse Events. RESULTS: Sixty hundred and ninety-five patients (90.6%) included in the TOPIC-trial had no variant in TPMT, of which 45 (6.5%) developed leucopenia. Median time to leucopenia was 56 (29-112) days. Multivariate analysis showed that use of mercaptopurine compared to azathioprine was associated with leucopenia (hazard ratio [HR] 2.61 [95% CIs, 1.39-4.88; P < .01]) and a higher baseline WBC count was protective (HR 0.80 [95% CIs, 0.71-0.89; P < .01]). Risk factors for infections were older age (per 10 year; HR 2.07 [95% CIs, 1.18-3.63; P = .01]) and concomitant use of biologic drugs (HR 2.15 [95% CIs, 1.14-4.07; P = .02]). CONCLUSIONS: Low baseline WBC count and mercaptopurine, due to a relatively higher dose, were risk factors for thiopurine-induced leucopenia in patients without a TPMT variant.

Irreversible Electroporation to Treat Malignant Tumor Recurrences Within the Pelvic Cavity: A Case Series.

OBJECTIVE: To describe the initial experience with irreversible electroporation (IRE) to treat pelvic tumor recurrences. METHODS: A retrospective single-center analysis was performed. Adverse events were recorded using Common Terminology Criteria of Adverse Events (CTCAE) 4.0. Clinical outcome was determined using pain- and general- symptom assessment, including Seddon's peripheral nerve injury (PNI) types. Radiological outcome was evaluated by comparing baseline with three-month 18F-FDG PET-CT follow-up. RESULTS: Eight patients (nine tumors [recurrences of primary rectal (n = 4), anal (n = 1), sigmoid (n = 1), cervical (n = 1), and renal cell carcinoma (n = 1)]) underwent percutaneous IRE as salvage therapy. Median longest tumor diameter was 3.7 cm (range 1.2-7.0). One CTCAE grade III adverse event (hemorrhage) and eight CTCAE grade II complications occurred in 6/8 patients: vagino-tumoral fistula (n = 1), lower limb motor loss (n = 3; PNI type II) with partial recovery in one patient, hypotonic bladder (n = 2; PNI types I and II) with complete recovery in one patient, and upper limb motor loss (n = 2; PNI type II) with partial recovery in both patients. No residual tumor tissue was observed at 3-month follow-up. After a median follow-up of 12 months, local progression was observed in 5/9 lesions (4/5 were >3 cm pre-IRE); one lesion was successfully retreated. Debilitating preprocedural pain (n = 3) remained unchanged (n = 1) or improved (n = 2). CONCLUSION: IRE may represent a suitable technique to treat pelvic tumor recurrences, although permanent neural function loss can occur. Complete ablation seems realistic for smaller lesions; for larger lesions symptom control should be the focus.

Early prediction of thiopurine-induced hepatotoxicity in inflammatory bowel disease.

BACKGROUND: Hepatotoxicity, gastrointestinal complaints and general malaise are common limiting adverse reactions of azathioprine and mercaptopurine in IBD patients, often related to high steady-state 6-methylmercaptopurine ribonucleotide (6-MMPR) metabolite concentrations. AIM: To determine the predictive value of 6-MMPR concentrations 1 week after treatment initiation (T1) for the development of these adverse reactions, especially hepatotoxicity, during the first 20 weeks of treatment. METHODS: The cohort study consisted of the first 270 IBD patients starting thiopurine treatment as part of the Dutch randomised-controlled trial evaluating pre-treatment thiopurine S-methyltransferase genotype testing (ClinicalTrials.gov NCT00521950). Blood samples for metabolite assessment were collected at T1. Hepatotoxicity was defined by alanine aminotransaminase elevations >2 times the upper normal limit or a ratio of alanine aminotransaminase/alkaline phosphatase ≥5. RESULTS: Forty-seven patients (17%) presented hepatotoxicity during the first 20 weeks of thiopurine treatment. A T1 6-MMPR threshold of 3615 pmol/8 × 108 erythrocytes was defined. Analysis of patients on stable thiopurine dose (n = 174) showed that those exceeding the 6-MMPR threshold were at increased risk of hepatotoxicity: OR = 3.8 (95% CI: 1.8-8.0). Age, male gender and BMI were significant determinants. A predictive algorithm was developed based on these determinants and the 6-MMPR threshold to assess hepatotoxicity risk [AUC = 0.83 (95% CI: 0.75-0.91)]. 6-MMPR concentrations above the threshold also correlated with gastrointestinal complaints: OR = 2.4 (95% CI: 1.4-4.3), and general malaise: OR = 2.0 (95% CI: 1.1-3.7). CONCLUSIONS: In more than 80% of patients, thiopurine-induced hepatotoxicity could be explained by elevated T1 6-MMPR concentrations and the independent risk factors age, gender and BMI, allowing personalised thiopurine treatment in IBD to prevent early failure.

No relevant excess prevalence of myotonic dystrophy type 2 in patients with suspected fibromyalgia syndrome.

Myotonic dystrophy type 2 (DM2) is a rare, autosomal dominant, multisystem disorder with proximal weakness, myotonia, pain and cataract as important symptoms. Given the assumed underreporting of DM2 in the Netherlands combined with the predominant role of pain in DM2 as well as in fibromyalgia syndrome (FMS), we hypothesized there will be an excess prevalence of DM2 in patients with (suspected) FMS. Our objective was to determine the prevalence of DM2 in patients with suspected FMS. A prevalence of 2% was considered a relevant excess frequency. Between November 2011 and April 2014, 398 patients with suspected FMS who had been assessed by a rheumatologist participated in this cross-sectional study. 95% of the study population was female, with a mean age of 42 years. The final ICD-9 diagnoses were collected, in 96% the diagnosis was FMS. 92% met the 2010 American College of Rheumatology (ACR) diagnostic criteria for FMS. A questionnaire including neuromuscular symptoms was completed. Creatine kinase was determined, and genetic testing for DM2 was conducted in all patients. DM2 was established in only one patient (0.25%, 95% CI 0.04-1.4%), thus disapproving our hypothesis of a relevant prevalence of 2%. Our results suggest that patients with suspected FMS should not routinely be tested for DM2.

[Economic burden of Clostridium difficile enterocolitis in German hospitals based on routine DRG data]. / Ökonomische Auswirkungen einer Clostridium-difficile-Enterokolitis in deutschen Krankenhäusern auf der Basis von DRG-Kostendaten.

BACKGROUND: Clostridium difficile associated diarrhea (CDAD) is not only a increasing medical but also economical problem. METHODS: Data from the DRG project group of the German society for digestive and metabolic diseases (DGVS) were analyzed for CDAD. Out of 430,875 cases from 37 German hospitals 2,767 cases were grouped by having CDAD either as primary (PD) or secondary diagnosis (SD; likely to be from a hospital source) in an initial or recurring hospital stay (RD). For comparison non-CDAD cases from the same hospitals from that year where matched using propensity score matching. As endpoints we defined LOS (length of stay), difference of LOS to national average LOS, total costs per case and difference between costs and revenue for all three groups. RESULTS: Patients from the PD group (n = 817) showed a mean LOS of 11.2 days compared to 8.5 days for the control group, 4,132 € mean cost per case (536 € more than control) and a mean loss of -1,064 € per case compared to -636 €. In the SD group (n = 1,840) patients stayed in the hospital for 28.8 days (control: 18.1 days), had costs of 19,381 € (control: 13,082 €) and a loss of -3,442 € compared to -849 € in the control group. Recurring cases (RD; n = 110) showed a LOS of 37.3 days (control: 21.3 days), had even higher costs (20.755 € vs. 13,101 €) and higher losses (-4,196 € vs. -1,109 €). CONCLUSION: By extrapolating these findings CDAD not only harms patients but generates a yearly cost burden of 464 million € for the German healthcare system including a loss of 197 million € for German hospitals. To the authors' opinion sufficient measures against CDAD should include pre hospital risk reduction programs, introduction of effective therapeutic and hygienic strategies in hospitals as well as improvements in documentation for these cases to support further developments of the German DRG system.

RYR1-related myopathies: a wide spectrum of phenotypes throughout life.

BACKGROUND AND PURPOSE: Although several recent studies have implicated RYR1 mutations as a common cause of various myopathies and the malignant hyperthermia susceptibility (MHS) trait, many of these studies have been limited to certain age groups, confined geographical regions or specific conditions. The aim of the present study was to investigate the full spectrum of RYR1-related disorders throughout life and to use this knowledge to increase vigilance concerning malignant hyperthermia. METHODS: A retrospective cohort study was performed on the clinical, genetic and histopathological features of all paediatric and adult patients in whom an RYR1 mutation was detected in a national referral centre for both malignant hyperthermia and inherited myopathies (2008-2012). RESULTS: The cohort of 77 non-related patients (detection rate 28%) included both congenital myopathies with permanent weakness and 'induced' myopathies such as MHS and non-anaesthesia-related episodes of rhabdomyolysis or hyperCKemia, manifested throughout life and triggered by various stimuli. Sixty-one different mutations were detected, of which 24 were novel. Some mutations are present in both dominant (MHS) and recessive modes (congenital myopathy) of inheritance, even within families. Histopathological features included an equally wide spectrum, ranging from only subtle abnormalities to prominent cores. CONCLUSIONS: This broad range of RYR1-related disorders often presents to the general paediatric and adult neurologist. Its recognition is essential for genetic counselling and improving patients' safety during anaesthesia. Future research should focus on in vitro testing by the in vitro contracture test and functional characterization of the large number of RYR1 variants whose precise effects currently remain uncertain.

[Improvement of cost allocation in gastroenterology by introduction of a novel service catalogue covering the complete spectrum of endoscopic procedures]. / Verbesserung der Kostenkalkulation in der Gastroenterologie durch Einführung eines neuen Leistungskatalogs für alle endoskopischen Prozeduren.

BACKGROUND: The German hospital reimbursement system (G-DRG) is incomplete for endoscopic interventions and fails to differentiate between complex and simple procedures. This is caused by outdated methods of personnel-cost allocation. METHODS: To establish an up-to-date service catalogue 50 hospitals made their anonymized expense-budget data available to the German-Society-of-Gastroenterology (DGVS). 2.499.900 patient-datasets (2011-2013) were used to classify operation-and-procedure codes (OPS) into procedure-tiers (e.g. colonoscopy with biopsy/colonoscopy with stent-insertion). An expert panel ranked these tiers according to complexity and assigned estimates of physician time. From June to November 2014 exact time tracking data for a total 38.288 individual procedures were collected in 119 hospitals to validate this service catalogue. RESULTS: In this three-step process a catalogue of 97 procedure-tiers was established that covers 99% of endoscopic interventions performed in German hospitals and assigned validated mean personnel-costs using gastroscopy as standard. Previously, diagnostic colonoscopy had a relative personnel-cost value of 1.13 (compared to gastroscopy 1.0) and rose to 2.16, whereas diagnostic ERCP increased from 1.7 to 3.62, more appropriately reflecting complexity. Complex procedures previously not catalogued were now included (e.g. gastric endoscopic submucosal dissection: 16.74). DISCUSSION: This novel service catalogue for GI-endoscopy almost completely covers all endoscopic procedures performed in German hospitals and assigns relative personnel-cost values based on actual physician time logs. It is to be included in the national coding recommendation and should replace all prior inventories for cost distribution. The catalogue will contribute to a more objective cost allocation and hospital reimbursement - at least until time tracking for endoscopy becomes mandatory.

Somatic mosaicism for the COL7A1 mutation p.Gly2034Arg in the unaffected mother of a patient with dystrophic epidermolysis bullosa pruriginosa.

Dystrophic epidermolysis bullosa (DEB) is a heritable blistering disorder caused by mutations in the type VII collagen gene, COL7A1. Although revertant mosaicism is well known in DEB, 'forward' somatic mosaicism, in which a pathogenic mutation arises on a wild-type (WT) background, extending beyond the germ cells, has not been reported. It is therefore unknown what proportion of sporadic dominant DEB (DDEB) cases result from de novo mutations or somatic mosaic parents. In the clinically unaffected mother of a patient with DDEB pruriginosa due to the p.Gly2034Arg mutation, we identified the p.Gly2034Arg mutation in a proportion of lymphocytes and skin cells (mutational load 10-25%). Our data emphasize that forward mosaicism occurs in DDEB and highlight that mutation analysis should always be performed in the parents of sporadic DDEB patients to confirm the de novo status of the mutation. Ultimately, this will reveal the frequency of true de novo mutations and somatic mosaicism in parents, which has important implications for genetic counselling. Our data indicate that the threshold of mutant type VII procollagen to develop DDEB must be higher than 10-25%, which provides a rationale for therapeutic approaches aimed at increasing the WT : mutant type VII collagen ratio.

Anaesthetic management during open and percutaneous irreversible electroporation.

BACKGROUND: Irreversible electroporation (IRE) is a novel tumour ablation technique involving repetitive application of electrical energy around a tumour. The use of pulsed electrical gradients carries a risk of cardiac arrhythmias, severe muscle contractions, and seizures. We aimed to identify IRE-related risks and the appropriate precautions for anaesthetic management. METHODS: All patients who were treated with IRE were prospectively included. Exclusion criteria were arrhythmias, congestive heart failure, active coronary artery disease, and epilepsy. All procedures were performed under general anaesthesia with complete muscle relaxation during ECG-synchronized pulsing. Adverse events, cardiovascular effects, blood samples, cerebral activity, and post-procedural pain were analysed. RESULTS: Twenty-eight patients underwent 30 IRE sessions for tumours in the liver, pancreas, kidney, and lesser pelvis. No major adverse events occurred during IRE. Median systolic and diastolic blood pressure increased by 44 mm Hg (range -7 to 108 mm Hg) and 19 mm Hg (range 1-50 mm Hg), respectively. Two transient minor cardiac arrhythmias without haemodynamic consequences were observed. Muscle contractions were mild and IRE caused no reactive brain activity on a simplified EEG. Pain in the first 24 h after percutaneous IRE was generally mild, but higher pain scores were reported after pancreatic treatment (mean VAS score 3; range 0-9). CONCLUSIONS: Side-effects during IRE on tumours in the liver, pancreas, kidney, and lesser pelvis seem mild and manageable when current recommendations for anaesthesia management, including deep muscle relaxation and ECG synchronized pulsing, are followed. Electrical pulses do not seem to cause reactive cerebral activity and evidence for pre-existing atrial fibrillation as an absolute contra-indication for IRE is questionable.

Ablation of colorectal liver metastases by irreversible electroporation: results of the COLDFIRE-I ablate-and-resect study.

OBJECTIVES: Irreversible electroporation (IRE) is a new ablation technique that relies on high-voltage electrical pulses. This clinical study evaluates the pathological response of colorectal liver metastases (CRLM) treated with IRE and the clinical safety and feasibility. METHODS: Ten patients with resectable CRLM were included. During laparotomy, the metastases were treated with IRE and resected 60 min later. Safety and feasibility were assessed based on adverse events, laboratory values, technical success and intra-operative ultrasound findings. Tissue response was assessed using triphenyl tetrazolium chloride (TTC) vitality staining and (immuno)histochemical stainings (HE, complement-3d and caspase-3). RESULTS: Ten lesions with a mean diameter of 2.4 cm were successfully electroporated and resected, on average, 84 min later (range 51-153 min). One minor transient cardiac arrhythmia occurred during IRE. Ultrasound showed a sharply demarcated hypoechoic ablation zone around the tumour. TTC showed avitality of all lesions, covering the complete tumour in 8/10 lesions. Although immunohistochemistry proved heterogeneous and difficult to interpret within the tumours, it confirmed irreversible cell damage in the tumour-free margin of all specimens. CONCLUSIONS: This ablate-and-resect study demonstrated avitality caused by IRE of CRLM in humans. Further characterisation of tissue- and tumour-specific electrical properties is warranted to improve ablation protocols for maximised tissue ablation. KEY POINTS: • Irreversible electroporation induces cell death in colorectal liver metastases within 1 h. • The ablation zone shows a sharp demarcation between avital and vital tissue. • Apoptosis is involved in cell death of colorectal liver metastases after IRE. • Effects of IRE can be monitored real-time using intraoperative ultrasound. • Local electrical heterogeneities of tumour tissue may require tumour-specific ablation protocols.

Noonan syndrome: comparing mutation-positive with mutation-negative dutch patients.

Noonan syndrome (NS) is an autosomal dominant disorder characterized by facial dysmorphisms, short stature and congenital heart defects. The disorder is genetically heterogeneous and shows clinical overlap with other RASopathies. These syndromes are caused by mutations in a variety of genes leading to dysregulation of the RAS-MAPK pathway: PTPN11, KRAS, SOS1, RAF1, CBL, SHOC2, NRAS, BRAF, MAP2K1, MAP2K2, HRAS, NF1 and SPRED1. In this study, we conduct a genotype-phenotype analysis of 33 patients with a clinical diagnosis of NS without a PTPN11 mutation. Mutation analysis of the genes involved in RASopathies was performed, except for NF1 and SPRED1. In 14 (42%) NS patients, a mutation was found, 7 (21%) had a mutation in SOS1, 3 (9%) in RAF1 and 1 (3%) in KRAS, MAP2K2, BRAF and SHOC2 each. The phenotype of these mutation-positive cases corresponded to that described in the literature. In the cases with a BRAF and MAP2K2 mutation, the diagnosis cardio-facio-cutaneous syndrome was made. The patient with the SHOC2 mutation had features compatible with 'Noonan-like syndrome with loose anagen hair'. Three major clinical features of NS - a typical face, short stature and a pulmonary valve stenosis - were less frequently present in the group without a mutation. Missense mutations in genes encoding proteins of the RAS-MAPK pathway cause NS. The 3 major clinical features of NS were less frequently present in the mutation-negative patients, which stresses the importance of the syndrome-specific symptoms of the face, heart and short stature in NS. However, all mutation-negative cases met the NS criteria, indicating that the involvement of novel genes is to be expected.

ATL1 and REEP1 mutations in hereditary and sporadic upper motor neuron syndromes.

SPAST mutations are the most common cause of autosomal dominant hereditary spastic paraplegias (AD-HSPs), but many spastic paraplegia patients are found to carry no mutations in this gene. In order to assess the contribution of ATL1 and REEP1 in AD-HSP, we performed mutational analysis in 27 SPAST-negative AD-HSP families. We found three novel ATL1 mutations and one REEP1 mutation in five index-patients. In 110 patients with sporadic adult-onset upper motor neuron syndromes, a novel REEP1 mutation was identified in one patient. Apart from a significantly younger age at onset in ATL1 patients and restless legs in some, the clinical phenotype of ATL1 and REEP1 was similar to other pure AD-HSPs.

Bipolar radiofrequency ablation for symptomatic giant (>10 cm) hepatic cavernous haemangiomas: initial clinical experience.

AIM: To describe initial clinical experience with bipolar radiofrequency ablation (RFA) for symptomatic giant hepatic haemangiomas. MATERIALS AND METHODS: Four consecutive patients with a large-volume, symptomatic hepatic cavernous haemangioma of >10 cm were treated with bipolar RFA during laparotomy with ultrasound guidance. Complications were carefully noted. Clinical and radiological effectiveness were evaluated comparing baseline with 3 and 6 months follow-up of symptom assessments and upper abdominal magnetic resonance imaging (MRI) or computed tomography (CT). RESULTS: RFA was successfully performed for all four giant haemangiomas. No major complications were observed. Peri-procedural shrinking was remarkable and intermediate-term volume reduction ranged from 58-92% after 6 months. Symptom relief after 6 months was complete in two patients and considerable in the other two. CONCLUSION: Preliminary results suggest intra-operative bipolar RFA to be a safe, feasible, and effective technique for treatment of giant symptomatic hepatic cavernous haemangiomas.

Mutations in C8orf37, encoding a ciliary protein, are associated with autosomal-recessive retinal dystrophies with early macular involvement.

Cone-rod dystrophy (CRD) and retinitis pigmentosa (RP) are clinically and genetically overlapping heterogeneous retinal dystrophies. By using homozygosity mapping in an individual with autosomal-recessive (ar) RP from a consanguineous family, we identified three sizeable homozygous regions, together encompassing 46 Mb. Next-generation sequencing of all exons, flanking intron sequences, microRNAs, and other highly conserved genomic elements in these three regions revealed a homozygous nonsense mutation (c.497T>A [p.Leu166(∗)]) in C8orf37, located on chromosome 8q22.1. This mutation was not present in 150 ethnically matched control individuals, single-nucleotide polymorphism databases, or the 1000 Genomes database. Immunohistochemical studies revealed C8orf37 localization at the base of the primary cilium of human retinal pigment epithelium cells and at the base of connecting cilia of mouse photoreceptors. C8orf37 sequence analysis of individuals who had retinal dystrophy and carried conspicuously large homozygous regions encompassing C8orf37 revealed a homozygous splice-site mutation (c.156-2A>G) in two siblings of a consanguineous family and homozygous missense mutations (c.529C>T [p.Arg177Trp]; c.545A>G [p.Gln182Arg]) in siblings of two other consanguineous families. The missense mutations affect highly conserved amino acids, and in silico analyses predicted that both variants are probably pathogenic. Clinical assessment revealed CRD in four individuals and RP with early macular involvement in two individuals. The two CRD siblings with the c.156-2A>G mutation also showed unilateral postaxial polydactyly. These results underline the importance of disrupted ciliary processes in the pathogenesis of retinal dystrophies.