Clinical characteristics and multimodal imaging can help diagnosing and treating mild malformation of cortical development with oligodendroglial hyperplasia and epilepsy.

OBJECTIVE: Mild malformation of cortical development with oligodendroglial hyperplasia and epilepsy (MOGHE) is a recently described, histopathologically and molecularly defined (SLC35A2-mutated) type of cortical malformation. Although increasingly recognized, the diagnosis of MOGHE remains a challenge. We present the characteristics of the first six patients diagnosed in Bulgaria, with the aim to facilitate identification, proper presurgical evaluation, and surgical treatment approach in this disease. METHODS: Revision of histopathological specimens of 202 patients operated on for drug-resistant focal epilepsy identified four cases with MOGHE. Another two were suggested, based on clinical characteristics and subsequently, were histologically confirmed. Sanger SLC35A2 sequencing on paraffin-embedded or fresh-frozen brain tissue was performed. Analysis of seizure types, neuropsychological profiles, electroencephalographic (EEG), imaging features and epilepsy surgery outcomes was done. RESULTS: Three out of the six cases (50%) harbored pathogenic SLC35A2 mutations. One patient had a heterozygous somatic variant with uncertain significance. Clinical characteristics included epilepsy onset in infancy (in 100% under 3 years of age), multiple seizure types, and moderate or severe intellectual/developmental delay. Epileptic spasms with hypsarrhythmia on EEG were the initial seizure type in five patients. The subsequent seizure types resembled those in Lennox-Gastaut syndrome. The majority of the patients (n = 4) presented prominent and persisting autistic features. Magnetic resonance imaging (MRI) showed multilobar (n = 6) and bilateral (n = 3) lesions, affecting the frontal lobes (n = 5; bilaterally in three) and characterized by increased signal on T2/fluid-attenuated inversion recovery (FLAIR). Voxel-based morphometric MRI post-processing and positron emission tomography helped determining the localization and extent of the lesions and presumed epileptogenic zones. After surgery, four patients (66.7%) were seizure-free ≥2 years. Interestingly, all seizure-free patients carried somatic SLC35A2-alterations. SIGNIFICANCE: Epileptic spasms, early prominent neuropsychological disturbances, MRI-T2/FLAIR hyperintense lesions with cortico-subcortical blurring, frequently multilobar and especially frontal, can preoperatively help to suspect MOGHE. Epilepsy surgery is still the only successful treatment option in MOGHE.

Advancing the Understanding of Vesicle-Associated Membrane Protein 1-Related Congenital Myasthenic Syndrome: Phenotypic Insights, Favorable Response to 3,4-Diaminopyridine, and Clinical Characterization of Five New Cases.

BACKGROUND: Congenital myasthenic syndromes (CMS) are a group of inherited neuromuscular junction (NMJ) disorders arising from gene variants encoding diverse NMJ proteins. Recently, the VAMP1 gene, responsible for encoding the vesicle-associated membrane protein 1 (VAMP1), has been associated with CMS. METHODS: This study presents a characterization of five new individuals with VAMP1-related CMS, providing insights into the phenotype. RESULTS: The individuals with VAMP1-related CMS exhibited early disease onset, presenting symptoms prenatally or during the neonatal period, alongside severe respiratory involvement and feeding difficulties. Generalized weakness at birth was a common feature, and none of the individuals achieved independent walking ability. Notably, all cases exhibited scoliosis. The clinical course remained stable, without typical exacerbations seen in other CMS types. The response to anticholinesterase inhibitors and salbutamol was only partial, but the addition of 3,4-diaminopyridine (3,4-DAP) led to significant and substantial improvements, suggesting therapeutic benefits of 3,4-DAP for managing VAMP1-related CMS symptoms. Noteworthy is the identification of the VAMP1 (NM_014231.5): c.340delA; p.Ile114SerfsTer72 as a founder variant in the Iberian Peninsula and Latin America. CONCLUSIONS: This study contributes valuable insights into VAMP1-related CMS, emphasizing their early onset, arthrogryposis, facial and generalized weakness, respiratory involvement, and feeding difficulties. Furthermore, the potential efficacy of 3,4-DAP as a useful therapeutic option warrants further exploration. The findings have implications for clinical management and genetic counseling in affected individuals. Additional research is necessary to elucidate the long-term outcomes of VAMP1-related CMS.

Comparison of the ABC and ACMG systems for variant classification.

The ABC and ACMG variant classification systems were compared by asking mainly European clinical laboratories to classify variants in 10 challenging cases using both systems, and to state if the variant in question would be reported as a relevant result or not as a measure of clinical utility. In contrast to the ABC system, the ACMG system was not made to guide variant reporting but to determine the likelihood of pathogenicity. Nevertheless, this comparison is justified since the ACMG class determines variant reporting in many laboratories. Forty-three laboratories participated in the survey. In seven cases, the classification system used did not influence the reporting likelihood when variants labeled as "maybe report" after ACMG-based classification were included. In three cases of population frequent but disease-associated variants, there was a difference in favor of reporting after ABC classification. A possible reason is that ABC step C (standard variant comments) allows a variant to be reported in one clinical setting but not another, e.g., based on Bayesian-based likelihood calculation of clinical relevance. Finally, the selection of ACMG criteria was compared between 36 laboratories. When excluding criteria used by less than four laboratories (<10%), the average concordance rate was 46%. Taken together, ABC-based classification is more clear-cut than ACMG-based classification since molecular and clinical information is handled separately, and variant reporting can be adapted to the clinical question and phenotype. Furthermore, variants do not get a clinically inappropriate label, like pathogenic when not pathogenic in a clinical context, or variant of unknown significance when the significance is known.

MSL2 variants lead to a neurodevelopmental syndrome with lack of coordination, epilepsy, specific dysmorphisms, and a distinct episignature.

Epigenetic dysregulation has emerged as an important etiological mechanism of neurodevelopmental disorders (NDDs). Pathogenic variation in epigenetic regulators can impair deposition of histone post-translational modifications leading to aberrant spatiotemporal gene expression during neurodevelopment. The male-specific lethal (MSL) complex is a prominent multi-subunit epigenetic regulator of gene expression and is responsible for histone 4 lysine 16 acetylation (H4K16ac). Using exome sequencing, here we identify a cohort of 25 individuals with heterozygous de novo variants in MSL complex member MSL2. MSL2 variants were associated with NDD phenotypes including global developmental delay, intellectual disability, hypotonia, and motor issues such as coordination problems, feeding difficulties, and gait disturbance. Dysmorphisms and behavioral and/or psychiatric conditions, including autism spectrum disorder, and to a lesser extent, seizures, connective tissue disease signs, sleep disturbance, vision problems, and other organ anomalies, were observed in affected individuals. As a molecular biomarker, a sensitive and specific DNA methylation episignature has been established. Induced pluripotent stem cells (iPSCs) derived from three members of our cohort exhibited reduced MSL2 levels. Remarkably, while NDD-associated variants in two other members of the MSL complex (MOF and MSL3) result in reduced H4K16ac, global H4K16ac levels are unchanged in iPSCs with MSL2 variants. Regardless, MSL2 variants altered the expression of MSL2 targets in iPSCs and upon their differentiation to early germ layers. Our study defines an MSL2-related disorder as an NDD with distinguishable clinical features, a specific blood DNA episignature, and a distinct, MSL2-specific molecular etiology compared to other MSL complex-related disorders.

MiRNA Signatures Related to Invasiveness and Recurrence in Patients With Non-Functioning Pituitary Neuroendocrine Tumors.

PURPOSE: This preliminary study aimed to analyze and identify differentially expressed miRNAs in Bulgarian patients with non-functioning pituitary neuroendocrine tumors (NFPitNET). The relationship between deregulated miRNAs and tumor invasiveness, recurrence, and size was determined. METHODS: Twenty patients with NFPitNET were selected and fresh pituitary tumor tissues were collected. RNA containing miRNAs were isolated using miRNAeasy mini kit and analyzed by quantitative real-time polymerase chain reaction (PCR) using LNA miRNA Cancer-Focus PCR Panel (Qiagen). RESULTS: Three miRNAs (miR-210-3p, miR-149-3p, and miR-29b-3p) were deregulated in invasive compared to non-invasive NFPitNETs. Differential expression of four-miRNA signatures - miRNA-17, miR-19, miR-106a, and miR-20, correlated with patient recurrence. CONCLUSION: This prospective pilot study selected a unique miRNA expression profile, that correlates with invasiveness and recurrence in non-functioning pituitary neuroendocrine tumors. Moreover, some of the selected miRNAs are reported for the first time in patients with this disease, shedding light on the molecular mechanisms involved in pituitary pathogenesis. The identified miRNAs demonstrate potential as biomarkers, deserving further investigation in a larger cohort to validate their clinical applicability.

Case Report: Transthyretin Glu54Leu-a rare mutation with predominant cardiac phenotype.

We report two unrelated Bulgarian families with hereditary transthyretin (ATTR) amyloidosis due to a rare p.Glu74Leu (Glu54Leu) pathogenic variant found in seven individuals-three of them symptomatic. Only one family with the same variant and with a Swedish origin has been clinically described so far. Our patients are characterized by predominant cardiac involvement, very much similar to the Swedish patients. Although the initial complaint was bilateral carpal tunnel syndrome, advanced amyloid cardiomyopathy was found in two symptomatic carriers at diagnosis with heart failure manifestations. The neurological involvement was considered as mild, with mainly sensory signs and symptoms being present. We followed a non-biopsy algorithm to confirm the diagnosis. Tafamidis 61 mg has been initiated as the only approved disease modifying treatment for ATTR cardiomyopathy. Clinical stability in the absence of adverse events has been observed at follow up.

Navigating the ALS Genetic Labyrinth: The Role of MAPT Haplotypes.

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease characterized by wide clinical and biological heterogeneity, with a large proportion of ALS patients also exhibiting frontotemporal dementia (FTD) spectrum symptoms. This project aimed to characterize risk subtypes of the H1 haplotype within the MAPT (microtubule-associated protein tau) gene, according to their possible effect as a risk factor and as a modifying factor in relation to the age of disease onset. One hundred patients from Bulgaria with sporadic ALS were genotyped for the variants rs1467967, rs242557, rs1800547, rs3785883, rs2471738, and rs7521. Haploview 4.2 and SHEsisPlus were used to reconstruct haplotype frequencies using genotyping data from the 1000 Genomes project as controls. Genotype-phenotype correlation was investigated in the context of age of disease onset and risk of disease development. While the individual variants of the subtypes do not influence the age of onset of the disease, a correlation was found between the specific haplotype GGAGCA (H1b) and the risk of developing sALS, with results showing that individuals harboring this haplotype have a nearly two-fold increased risk of developing sALS compared to other H1 subtypes. The results from this study suggest that fine transcriptional regulation at the MAPT locus can influence the risk of ALS.

Novel insights on GTPBP3-associated hypertrophic cardiomyopathy.

About 100 genes have been associated with cardiomyopathies with genotype-phenotype correlations often hard to establish. Genetic testing may help to confirm the genetic diagnosis and assess the risk of inheritance in the family. A 25-year old male with hypertrophic cardiomyopathy and fasciculoventricular accessory pathway was referred for genetic testing by his cardiologist. Targeted PRKAG2 screening and whole-exome sequencing were performed, followed by Sanger sequencing segregation analysis in the family. The PRKAG2 gene screening was negative. Whole-exome sequencing revealed the following four variants in the patient: c.181G>C (p.Ala61Pro) and c.1199C>T (p.Thr400Met) in the GTPBP3 gene, as well as c.752C>T (p.Thr251Ile) and c.1760C>T (p.Pro587Leu) in the POLG gene. Family segregation analysis showed that the patient's mother is a carrier of variant c.181G>C and the patient's paternal grandmother is a carrier of variant c.1199C>T in the GTPBP3 gene, which is in accordance with an autosomal recessive model of inheritance of the disease. Both variants in the POLG are found paternally inherited in the patient's healthy half-brother, thus are not considered disease-causing. GTPBP3 variants have been reported in patients with hypertrophic cardiomyopathy, associated with combined oxidative phosphorylation deficiency 23. These novel variants represent the probable cause of the observed clinical symptoms in the patient.

Arginase deficiency in Bulgaria: first cases and potential endemic region for the disorder.

Arginase deficiency is an autosomal recessive urea cycle disorder caused by pathogenic variants in the ARG1 gene. The clinical features of the disease include spasticity, tremour, ataxia, hypotonia, microcephaly and seizures. Growth delay can also be observed in the affected individuals. Here we describe the results from molecular-genetic analysis of two patients with arginase deficiency. In the first case, we reported a novel homozygous missense variant c.775G>A p.(Gly259Ser) in a patient with Bulgarian ethnic origin. In the second case, a novel homozygous splice site variant c.329+1G>A was detected in a patient from a consanguineous family of Roma ethnic origin. A hundred samples of newborns of Roma origin were screened for variant c.329+1G>A and one individual was found to be a heterozygous carrier of variant c.329+1G> A. The results from this study indicated the necessity for screening of the Roma population with respect to the disease arginase deficiency in Bulgaria.

Novel variant c.92T > G (p.Val31Gly) in the PFN1 gene (ALS18) responsible for a specific phenotype in a large Bulgarian amyotrophic lateral sclerosis pedigree.

Objectives: Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disorder characterized by progressive deterioration of motor function, disability, and death. Variants in the PFN1 gene, encoding the Profilin-1 protein, are related to ALS18. Methods: We present a pedigree consisting of 3 generations and 4 affected individuals, 3 of which carry a novel heterozygous variant: c.92T > G (p.Val31Gly) in the PFN1 gene. This variant was discovered through means of whole exome sequencing (WES) and targeted analysis of ALS-related genes. Results: The mean age of onset in our pedigree was 59.75 (±10.11 SD) years with a significant difference between the first two generations (females) and the third (male) of 22.33 (±3.4 SD) years. For this ALS form, we observed a longer disease progression of 4 (±1.87 SD) years (three of four affected are still alive). Clinical manifestations displayed predominant impairment of the lower motor neuron (LMN) in one limb, with gradual involvement of other limbs. A novel heterozygous missense variant c.92T > G, p. Val31Gly (NM_005022.4) in exon 1 in the PFN1 gene was discovered through means of whole exome sequencing (WES). Segregation analysis in the family showed that the detected variant was inherited from the affected mother, and the affected aunt also turned out to be a variant carrier. Conclusions: ALS18 is a very rare form of the disease. We report here a relatively large pedigree with a novel variant, leading to late onset (after 50 years), initial involvement of the lower limbs and relatively slow progression.

Seven Years of Selective Genetic Screening Program and Follow-Up of Asymptomatic Carriers With Hereditary Transthyretin Amyloidosis in Bulgaria.

Hereditary transthyretin amyloidosis (ATTRv amyloidosis) is a rare, autosomal-dominant (AD) multisystem disorder resulting from the extracellular deposition of amyloid fibrils formed by a destabilized mutant form of transthyretin (TTR), a transport protein predominantly produced by the liver. Aim: The aims of the current study are to demonstrate the Bulgarian experience with the screening programs among the high-risk patient population over the last 7 years, to present the results from the therapy with TTR stabilizer in our cohort, as well as to stress on the importance of a follow-up of asymptomatic carriers with TTR pathogenic variants by a multidisciplinary team of specialists. Materials and Methods: In 2014, a screening program among the high-risk patient population for ATTRv was initiated in Bulgaria. On one hand, it was conducted to identify new patients and families among people with "red flag" clinical features, while on the other hand, the program aimed to identify TTR mutation carriers among the families with already genetically proven diagnoses. Sanger sequencing methodology was used to make fast target testing for mutations in the TTR gene in the suspected individuals. All of the identified carriers underwent subsequent evaluation for neurological, cardiac, gastroenterological, and neuro-ophthalmological involvement. Those considered affected were provided with multidisciplinary treatment and a follow-up. Results: As a result of a 7-year selective screening program among the high-risk patient population and relatives of genetically verified affected individuals, 340 carriers of TTR mutations were identified in Bulgaria with the following gene defects: 78.53% with Glu89Gln, 10.29% with Val30Met, 8.24% with Ser77Phe, 2.06% with Gly47Glu, and 0.59% with Ser52Pro. All of these affected displayed a mixed phenotype with variable ages at onset and rate of progression, according to their mutation. From the 150 patients treated with TTR stabilizer, 84 remained stable, while in other 66 patients the treatment was terminated either because of polyneuropathy progression or due to death. A program for a regular follow-up of asymptomatic carriers in the last 3 years enabled us to detect the transition of 39/65 to symptomatic patients and to initiate treatment in a timely manner. Conclusion: Bulgarian ATTRv patients display a mixed phenotype with some clinical peculiarities for each mutation that should be considered when treating the affected and the follow-up of the asymptomatic carriers of a specific gene defect.

Diagnostic, grading and prognostic role of a restricted miRNAs signature in primary and metastatic brain tumours. Discussion on their therapeutic perspectives.

At present, brain tumours remain one of the "hard-to-treat" malignancies with minimal improvement in patients' survival. Recently, miRNAs have been shown to correlate with oncogenesis and metastasis and have been investigated as potential biomarkers for diagnosis, prognosis and therapy prediction in different brain malignancies. The aim of the current study was to select an accurate and affordable brain tumour detection and grading approach. In the present study, we analysed the applicability of a restricted miRNA signature that could differentiate among patients with primary as well as metastatic brain tumours. Fresh tumour tissues were collected from Bulgarian patients (n = 38), including high-grade gliomas (n = 23), low-grade gliomas (n = 10) and brain metastases (n = 5) from lung cancer. Total RNAs enriched with microRNAs were isolated and differentially expressed miRNAs were analyzed by RT-qPCR using TaqMan Advanced miRNA assay. We selected a signature of miR-21, miR-10b, miR-7, miR-491 that showed good diagnostic potential in high-grade gliomas, low-grade gliomas and brain metastases compared with normal brain tissues. Our results showed that miR-10b could reliably differentiate brain metastases from high-grade gliomas, while miR-491 could distinguish low-grade from high-grade gliomas and brain metastases from low-grade gliomas. We observed that miR-21 and miR-7 correlated with disease recurrence, survival status and the Karnofsky Performance Status. The selected signature of miR-7, miR-21, miR-10b and miR-491 could be used as a highly accurate diagnostic, grading and prognostic biomarker in differentiating various types of brain tumours. Our data suggest that the 4-miRNAs signature could be further analysed for predicting treatment response and for future miRs-based targeted therapy. The ongoing studies on miRs-based targeted therapy related to our selected miRNA signature are also reviewed.

Screening for hereditary transthyretin amyloidosis in Bulgaria.

Transthyretin amyloid (ATTR) amyloidosis is a rare disorder with an adult-onset defined by the accumulation of misfolded fibrils predominantly in peripheral nerves, the heart, and the digestive tract. The disease is characterized by two forms - hereditary (ATTRv) or acquired (ATTRwt). Various point mutations in the transthyretin gene induce the hereditary form of the disease. For finding new cases of ATTR amyloidosis and proper screening, the establishment of a multidisciplinary team and a Centre of Excellence (CoE) is essential. CoE provides regular education and training for better diagnosis and treatment. In the current review, we focus on the importance of having a multidisciplinary team and CoE, the screening strategy for ATTR amyloidosis in Bulgaria, and assessments performed when a patient is first suspected of having this rare disease.

Characterization of population genetic structure of hereditary transthyretin amyloidosis in Bulgaria.

The hereditary transthyretin amyloidosis (ATTRv amyloidosis) is an autosomal dominant genetic disease characterized by amyloid formation in different tissues due to pathogenic variants in the TTR gene. Great heterogeneity in the penetrance and manifestation of ATTRv amyloidosis is observed. In Bulgaria, the most common TTR pathogenic variant is Glu89Gln. Other TTR pathogenic variants are also found - Val30Met, Ser77Phe, Gly47Glu and Ser52Pro. There is a proven founder effect for the Glu89Gln variant, thus the aim of the present study is to investigate the founder effect for the other TTR pathogenic variants in Bulgaria. Haplotype analysis was performed by using microsatellite markers close to the TTR gene. DNA samples from ATTRv amyloidosis patients and their healthy relatives were analyzed. Theoretical haplotype reconstruction was done with Arlequin v.3.01 software. The age of the most recent common ancestor (hypothetical founder) for the studied variants was calculated with the DMLE 2.2 software. In addition, DBS screening among 100 Roma newborns was done for the Gly47Glu TTR variant via direct Sanger sequencing. The reconstructed haplotypes of the patients were compared to their healthy relatives and to a control group of 40 healthy individuals. The results showed a possible founder effect for each of the studied variants. The Val30Met haplotype was compared to published haplotype data for this variant and no similarity was found. The result from the DBS screening showed no pathogenic TTR variants in exon 2 of the gene, so we considered the presence of the Gly47Glu variant in our population a sporadic event. With this study, we succeeded to gain a more complete picture of the population genetics of ATTRv amyloidosis in Bulgaria and made another step towards a more detailed understanding of the disease epidemiology.

MYH7-related disorders in two Bulgarian families: Novel variants in the same region associated with different clinical manifestation and disease penetrance.

Pathogenic variants in MYH7 cause a wide range of cardiac and skeletal muscle diseases with childhood or adult onset. These include dilated and/or hypertrophic cardiomyopathy, left ventricular non-compaction cardiomyopathy, congenital myopathies with multi-minicores and myofiber type disproportion, myosin storage myopathy, Laing distal myopathy and others (scapulo-peroneal or limb-girdle muscle forms). Here we report the results from molecular genetic analyses (NGS and Sanger sequencing) of 4 patients in two families with variable neuromuscular phenotypes with or without cardiac involvement. Interestingly, variants in MYH7 gene appeared to be the cause in all the cases. A novel nonsense variant c.5746C>T, p.(Gln1916Ter) was found in the patient in Family 1 who deceased at the age of 2 years 4 months with the clinical diagnosis of dilated cardiomyopathy, whose father died before the age of 40 years, due to cardiac failure with clinical diagnosis of suspected limb-girdle muscular dystrophy. A splice acceptor variant c.5560-2A>C in MYH7 was detected in the second proband and her sister, with late onset distal myopathy without cardiac involvement. These different phenotypes (muscular involvement with severe cardiomyopathy and pure late onset neuromuscular phenotype without heart involvement) may result from novel MYH7 variants, which most probably impact the LMM (light meromyosin) domain's function of the mature protein.

Human cytomegalovirus DNA detection in a recurrent glioblastoma multiforme tumour, but not in whole blood: a case report and discussion about the HCMV latency and therapy perspectives.

In the current study, a 58-year-old male patient presented with recurrent glioblastoma multiforme (GBM). The patient underwent surgical resection, 4 months earlier, followed by radiotherapy and chemotherapy. During the second surgical intervention, tumour tissue and whole blood were sampled and analysed for human cytomegalovirus (HCMV) DNA, immediate early (IE) mRNA and pp65 mRNA. HCMV DNA was detected only in the recurrent tumour tissue but not in the whole blood. Neither IE mRNA nor pp65 mRNA was expressed. Our result suggests HCMV latency in the brain tumour with detectable level of viral DNA. More data are needed to understand the HCMV infection chronology in the brain tumours but our data could be important for further studies of HCMV antigens on the tumour surface and anti-GBM therapy.

Cardiac involvement, morbidity and mortality in hereditary transthyretin amyloidosis because of p.Glu89Gln mutation.

BACKGROUND: Hereditary transthyretin amyloidosis is a systemic infiltrative disease, caused by a mutation in the transthyretin gene. p.Glu89Gln is the most common mutation in the Balkan countries. METHODS: We evaluated the clinical manifestations, cardiac involvement, morbidity and mortality in 78 patients with p.Glu89Gln mutation, verified through a DNA analysis. Clinical assessment, electrocardiogram and echocardiography were performed at the time of diagnosis. The patients have been followed for 30 months. RESULTS: All included patients were Caucasian, 39 (50%) - men, with median age at diagnosis of 56 years (42-73), median age at onset -- 53 years (35-69), starting significantly earlier in men (4.36, P = 0.004). Cardiac and neurological involvement was found in 74 (95%) patients. Pathological ECG was present in 65 (84%) patients, infarct pattern in 43 (56%), low voltage in 24 (31%). Echocardiography revealed an infiltrative cardiomyopathy with restrictive filling in 31 (40%) and ejection fraction less than 50% in 20 (27%) patients. Twenty-two patients (28%) died: 14 (64%) because of advanced heart failure, 6 (27%) died suddenly, 2 (9%) from an ischemic stroke. The median age at death was 58.5 years (52-72). No statistically significant sex difference in survival was observed; a significant difference in survival was found for the New York Heart Association class, familial amyloidotic polyneuropathy stage, ejection fraction, filling pattern and tafamidis treatment. CONCLUSION: Cardiac involvement is common and has significant prognostic implications in the evaluated patients with p.Glu89Gln mutation. Heart failure and rhythm disturbances are the main causes of death. An earlier identification of the disease is crucial to improve prognosis.

Transthyretin amyloidosis: Testing strategies and model for center of excellence support.

Appropriate testing strategies and strict model for Center Of Excellence (CoE) support are essential for the correct diagnosis, follow-up strategy and treatment plan for transthyretin (ATTR) amyloidosis. CoE is defined as a programme within a healthcare institution established to provide an exceptionally high concentration of expertise and related resources centred on a particular area of medicine, delivering associated care in a comprehensive, interdisciplinary fashion to afford the best patient outcome. Ideally, CoEs provide regular education and training for healthcare professionals and share knowledge and learning with other CoEs and specialists to ensure the highest standards of care. CoEs and testing strategies are of significant value to those with rare diseases and their families, as there is naturally low awareness among healthcare professionals, a phenomenon that potentially delays diagnosis and treatment. In this review, we focus on the importance of performing the most appropriate testing strategies for ATTR amyloidosis and establishing a CoE for this rare disease. We highlight our experience in establishing a CoE in Sofia, Bulgaria and define the fundamental steps needed to successfully launch a programme.

Fecal calprotectin levels are elevated in transthyretin amyloidosis patients with gastrointestinal manifestations.

Transthyretin amyloid (ATTR) amyloidosis is a rare systemic disorder characterized by amyloid deposits formed by misfolded monomers of the transthyretin. Gastrointestinal (GI) manifestations are common in ATTR amyloidosis; however, their pathogenesis is not fully elucidated. In the present study, we aim to evaluate the diagnostic role of fecal calprotectin (FC) in ATTR amyloidosis patients with GI manifestations.We recruited 21 consecutive ATTR amyloidosis patients and 42 sex and age-matched healthy controls. The presentation of GI symptoms and the severity of peripheral neuropathy were evaluated. Colonoscopy and FC assessment were performed in all subjects.Mean levels of FC in ATTR amyloidosis patients (184 µg/g [30-430]) were significantly higher thаn those of controls (40 µg/g [30-70]), P < .001. Receiver operating characteristic curve analysis indicated a FC cut-off level of 71 µg/g, which differentiates ATTR amyloidosis with GI manifestations from healthy subjects with 91% sensitivity, 100% specificity, 100% positive predictive value, 95% negative predictive value and 97% overall accuracy. FC values were significantly associated with the presence of neutrophilic granulocytic infiltration in the colonic mucosa (P = .002), with the presence of amyloid deposits in rectal mucosa (P = .007) and the presence of diarrhea (P = .046).FC levels are elevated in patients with ATTR amyloidosis with GI manifestations, which suggests an inflammatory component in the pathogenesis of the disease. The presence of elevated FC concentrations could help gastroenterologists to include ATTR amyloidosis in their diagnostic work-up.

Gastrointestinal Manifestations in Hereditary Transthyretin Amyloidosis associated with Glu89Gln Mutation.

AIMS: In the current study we aimed to explore the prevalence of gastrointestinal (GI) manifestations in hereditary transthyretin amyloid (hATTR) amyloidosis associated with Glu89Gln mutation. METHODS: We recruited 78 patients with hATTR amyloidosis associated with Glu89Gln mutation. The diagnosis of hATTR was defined by a documented transthyretin mutation through DNA analysis. Symptoms were recorded as present or absent at the time of enrollment into the study. The gastrointestinal (GI) symptoms checklist included the following items: early satiety, nausea, vomiting, constipation, alternating diarrhea/ constipation, diarrhea, fecal incontinence and unintentional weight loss. RESULTS: Forty-two patients (53.8%) reported at least one GI symptom or sign. Diarrhea was the most frequently reported (30.8%), followed by unintentional weight loss (28.2%) and nausea (21.8%). Fecal incontinence (3.8%) was the least common one. No significant gender related difference in overall GI symptom prevalence was found (females 52.16%, males 55%, p = 0.834). Type of disease onset was not related to GI prevalence (earlyonset 50%, late-onset 55.6%, p=0.650). After dividing the patients into groups with a disease duration of <5 years, 5-10 years and >10 years, respectively, the prevalence of GI symptoms was found to be significantly higher in later stages (26.3% vs. 55.0% vs. 78.9%, p = 0.005; OR 2.450, 95% CI 1.084-5.538). Gastrointestinal manifestations had no impact on survival (p=0.193). CONCLUSIONS: Gastrointestinal manifestations are very common in hATTR patients with Glu89Gln mutation and increase with disease duration. They are not associated with gender and onset of the disease and have no impact on patient survival. These results highlight the importance of a thorough evaluation of the GI function in patients with ATTR amyloidosis and should stimulate further studies on the phenotypic differences related to genotype and geographic origin.