Reassuring pregnancy outcomes in women with mild COL4A3-5-related disease (Alport syndrome) and genetic type of disease can aid personalized counseling.

Individualized pre-pregnancy counseling and antenatal care for women with chronic kidney disease (CKD) require disease-specific data. Here, we investigated pregnancy outcomes and long-term kidney function in women with COL4A3-5 related disease (Alport Syndrome, (AS)) in a large multicenter cohort. The ALPART-network (mAternaL and fetal PregnAncy outcomes of women with AlpoRT syndrome), an international collaboration of 17 centers, retrospectively investigated COL4A3-5 related disease pregnancies after the 20th week. Outcomes were stratified per inheritance pattern (X-Linked AS (XLAS)), Autosomal Dominant AS (ADAS), or Autosomal Recessive AS (ARAS)). The influence of pregnancy on estimated glomerular filtration rate (eGFR)-slope was assessed in 192 pregnancies encompassing 116 women (121 with XLAS, 47 with ADAS, and 12 with ARAS). Median eGFR pre-pregnancy was over 90ml/min/1.73m2. Neonatal outcomes were favorable: 100% live births, median gestational age 39.0 weeks and mean birth weight 3135 grams. Gestational hypertension occurred during 23% of pregnancies (reference: 'general' CKD G1-G2 pregnancies incidence is 4-20%) and preeclampsia in 20%. The mean eGFR declined after pregnancy but remained within normal range (over 90ml/min/1.73m2). Pregnancy did not significantly affect eGFR-slope (pre-pregnancy ß=-1.030, post-pregnancy ß=-1.349). ARAS-pregnancies demonstrated less favorable outcomes (early preterm birth incidence 3/11 (27%)). ARAS was a significant independent predictor for lower birth weight and shorter duration of pregnancy, next to the classic predictors (pre-pregnancy kidney function, proteinuria, and chronic hypertension) though missing proteinuria values and the small ARAS-sample hindered analysis. This is the largest study to date on AS and pregnancy with reassuring results for mild AS, though inheritance patterns could be considered in counseling next to classic risk factors. Thus, our findings support personalized reproductive care and highlight the importance of investigating kidney disease-specific pregnancy outcomes.

Cystinuria: clinical practice recommendation.

Cystinuria (OMIM 220100) is an autosomal recessive hereditary disorder in which high urinary cystine excretion leads to the formation of cystine stones because of the low solubility of cystine at normal urinary pH. We developed clinical practice recommendation for diagnosis, surgical and medical treatment, and follow-up of patients with cystinuria. Elaboration of these clinical practice recommendations spanned from June 2018 to December 2019 with a consensus conference in January 2019. Selected topic areas were chosen by the co-chairs of the conference. Working groups focusing on specific topics were formed. Group members performed systematic literature review using MEDLINE, drafted the statements, and discussed them. They included geneticists, medical biochemists, pediatric and adult nephrologists, pediatric and adult urologists experts in cystinuria, and the Metabolic Nephropathy Joint Working Group of the European Reference Network for Rare Kidney Diseases (ERKNet) and eUROGEN members. Overall 20 statements were produced to provide guidance on diagnosis, genetic analysis, imaging techniques, surgical treatment (indication and modalities), conservative treatment (hydration, dietetic, alkalinization, and cystine-binding drugs), follow-up, self-monitoring, complications (renal failure and hypertension), and impact on quality of life. Because of the rarity of the disease and the poor level of evidence in the literature, these statements could not be graded. This clinical practice recommendation provides guidance on all aspects of the management of both adults and children with cystinuria, including diagnosis, surgery, and medical treatment.

Epidemiology of Chronic Kidney Disease in Children: A Report from Lithuania.

Background and Objectives: The data on the prevalence of chronic kidney disease (CKD) in the pediatric population are limited. The prevalence of CKD ranges from 56 to 74.7 cases per million of the age-related population (pmarp). The most common cause of CKD among children is congenital anomalies of the kidney and urinary tract (CAKUT). With progressing CKD, various complications occur, and end-stage renal disease (ESRD) can develop. The aim of the study was to determine the causes, stage, prevalence, and clinical signs of CKD and demand for RRT (renal replacement therapy) among Lithuanian children in 2017 and to compare the epidemiological data of CKD with the data of 1997 and 2006. Materials and Methods: The data of 172 Lithuanian children who had a diagnosis of CKD (stage 2-5) in 1997 (n = 41), in 2006 (n = 65), and in 2017 (n = 66) were retrospectively analyzed. Physical development and clinical signs of children who had CKD (stage 2-5) in 2017 were assessed. Results: The prevalence of CKD stages 2-5 was 48.0 pmarp in 1997; 88.7 in 2006; and 132.1 in 2017 (p < 0.01). Congenital and hereditary diseases of the kidney in 1997 accounted for 66% of all CKD causes; in 2006, for 70%; and in 2017, for 79%. In 2017, children with CKD stages 4 or 5 (except transplanted children) had hypertension (87.5%) and anemia (50%) (p < 0.01). Children under ≤2 years with CKD were at a 3-fold greater risk of having elevated blood pressure (OR = 3.375, 95% CI: 1.186-9.904). Conclusions: There was no change in the number of children with CKD in Lithuania; however, the prevalence of CKD increased due to reduced pediatric population. CAKUT remains the main cause of CKD at all time periods. Among children with CKD stages 4 or 5, there were more children with hypertension and anemia. In children who were diagnosed with CKD at an early age hypertension developed at a younger age.

Is the coronary artery calcium score the first-line tool for investigating patients with severe hypercholesterolemia?

BACKGROUND: Coronary artery calcium (CAC) is known as a reliable tool for estimating risk of myocardial infarction, coronary death, all-cause mortality and is even used to evaluate suitable asymptomatic patients. We therefore aimed to evaluate whether CAC scoring can be applied in the algorithm for clinical examination of patients with severe hypercholesterolemia (SH). METHODS: During the period of 2016-2017 a total of 213 asymptomatic adults, underwent computed tomography angiography to evaluate their CAC scoring. The sample consisted of 110 patients with SH and 103 age and sex matched controls without dyslipidemia and established cardiovascular disease. RESULTS: In total there were 79 (37.2%) subjects with elevated (≥25th) CAC percentiles. Out of them 47 (59.5%) had SH and 32 (40.5%) did not. CAC score did not differ between groups (SH (+) 140.30 ± 185.72 vs SH (-) 87.84 ± 140.65, p = 0.146), however there was a comparable difference in how the participants of these groups distributed among different percentile groups (p = 0.044). Gender, blood pressure, tabaco use, physical activity, family history of coronary artery disease and diabetes mellitus were not associated with CAC score (p > 0.05). There were no significant correlations between biochemical parameters and CAC percentiles except for increase in lipoprotein(a) (p = 0.038). Achilles tendon pathology, visceral obesity, body mass index and increased waist-hip ratio were not associated with CAC percentiles either (p > 0.05). CONCLUSIONS: CAC score is not associated with presence of SH. CAC score is not an appropriate diagnostic tool in the algorithm for clinical examination of patients with SH. Further larger studies are needed to support our findings.

Genotype⁻Phenotype Correlation in a New Fabry-Disease-Causing Mutation.

Background: Fabry disease (FD) is a rare X-linked inherited lysosomal storage disorder caused by α-galactosidase A deficiency leading to intracellular glycosphingolipid accumulation. FD manifestation is multisystem, and can differ depending on disease-related genetic variants. Currently, more than 700 different FD-causing mutations have been identified in the human GLA gene. We identified a novel mutation in a Lithuanian family with classical manifestations of Fabry disease, revealing severe effects to the cardiovascular systems of heterozygous women. Case presentation: A 49-year-old woman underwent echocardiography due to progressive dyspnea that lasted seven years, reduced physical activity, and periodic cardiac arrhythmia. Echocardiography revealed left ventricular hypertrophy with normal diastolic function. The patient had experienced acroparesthesia in her upper limbs and abdominal pain since childhood, and in the last decade had experienced mild proteinuria without renal failure. Her renal biopsy was typical for Fabry disease. The patient's brain magnetic resonance imaging (MRI) (T2 flair) showed white matter hyperintensities lesions. DNA sequencing of the proband, her mother and one of her sons showed a novel GLA gene exon 2 mutation, c.270C>G (p.Cys90Trp). All three patients had decreased α-galactosidase A activity and specific FD manifestations. Conclusion: A novel GLA mutation, c.270C>G (p.Cys90Trp), was found in a Lithuanian family with a classical form of Fabry disease in heterozygous women with predominant cardiac involvement. However, the exact manifestation of this mutation is still unclear as it is newly reported and further research must be done.

Neutral pH and low-glucose degradation product dialysis fluids induce major early alterations of the peritoneal membrane in children on peritoneal dialysis.

The effect of peritoneal dialysates with low-glucose degradation products on peritoneal membrane morphology is largely unknown, with functional relevancy predominantly derived from experimental studies. To investigate this, we performed automated quantitative histomorphometry and molecular analyses on 256 standardized peritoneal and 172 omental specimens from 56 children with normal renal function, 90 children with end-stage kidney disease at time of catheter insertion, and 82 children undergoing peritoneal dialysis using dialysates with low-glucose degradation products. Follow-up biopsies were obtained from 24 children after a median peritoneal dialysis of 13 months. Prior to dialysis, mild parietal peritoneal inflammation, epithelial-mesenchymal transition and vasculopathy were present. After up to six and 12 months of peritoneal dialysis, blood microvessel density was 110 and 93% higher, endothelial surface area per peritoneal volume 137 and 95% greater, and submesothelial thickness 23 and 58% greater, respectively. Subsequent peritoneal changes were less pronounced. Mesothelial cell coverage was lower and vasculopathy advanced, whereas lymphatic vessel density was unchanged. Morphological changes were accompanied by early fibroblast activation, leukocyte and macrophage infiltration, diffuse podoplanin presence, epithelial mesenchymal transdifferentiation, and by increased proangiogenic and profibrotic cytokine abundance. These transformative changes were confirmed by intraindividual comparisons. Peritoneal microvascular density correlated with peritoneal small-molecular transport function by uni- and multivariate analysis. Thus, in children on peritoneal dialysis neutral pH dialysates containing low-glucose degradation products induce early peritoneal inflammation, fibroblast activation, epithelial-mesenchymal transition and marked angiogenesis, which determines the PD membrane transport function.

Renal Replacement Therapy in Children in Lithuania: Challenges, Trends, and Outcomes.

Background and Objectives: Pediatric renal replacement therapy (RRT) in Lithuania resumed in 1994 after a 12-year pause in renal transplantation. Management of end stage renal disease (ESRD) has changed, and outcomes have improved over decades. Our aim was to evaluate the dynamics of RRT in Lithuania in the period 1994⁻2015, describe its distinctive features, and compare our results with other countries. Materials and Methods: Data between 1994 and 2015 were collected from patients under the age of 18 years with ESRD receiving RRT. The data included: Hemodialysis (HD), peritoneal dialysis (PD), transplantation incidence and prevalence, transplant waiting time, dialysis modalities before transplantation, causes of ESRD and gender distribution in transplanted patients, and patient and graft survival. Results: RRT incidence and prevalence maintained an increase up until 2009. Sixty-four transplantations were performed. Juvenile nephronophthisis (25.9%) was the primary cause of ESRD in transplanted children. The transplant waiting time median was 8.0 months. The male to female ratio post-transplantation was 1.02. Patient survival after transplantation at 10 years was 90.0%, while graft survival for living (related) was 77.0% and 51.1% for deceased. Twelve patients died while on RRT. Conclusions: RRT numbers are increasing in Lithuania. HD is the primary treatment of choice before transplantation, with continued low numbers of preemptive transplantation. Patient survival post-transplantation is favorable, though graft survival is less satisfactory.

Factors Determining Parents' Decisions to Bring Their Children to the Pediatric Emergency Department for a Minor Illness.

BACKGROUND The number of children visiting Emergency Departments (EDs) is increasing in Lithuania; therefore, the aim of this study was to determine the factors influencing the parental decision to bring their child to the ED for a minor illness that could be managed in a primary healthcare setting, and to compare parents' and medical professionals' attitudes toward a child's health status and need for urgent care. MATERIAL AND METHODS A prospective observational study was performed at the tertiary-level teaching Children's Hospital in Vilnius. A total of 381 patients' parents were interviewed using an original questionnaire based on Andersen's behavioral model of healthcare utilization; in addition, the medical records of patients were reviewed to identify factors that might have an impact on parental decisions to bring their child to the ED for a minor health problem. The study participants were enrolled from October 1, 2013 to August 31, 2014. The urgency of medical care needed to be provided to the patients was evaluated by a tertiary-level triage system. RESULTS Based on the assessment of the triage nurses, the need for emergency care to patients was distributed as follows: 298 patients (78.2%) needed non-urgent care and 83 patients (21.8%) needed urgent care. More than one-third (38.8%) of the parents reported that they came to the ED due to their child's urgent care need and worsened child's health; however, the opinion of ED professionals indicated only a fifth of patients required urgent care. Parents who brought their children to the ED without physician referral were five times more likely to visit the ED during evening hours and on weekends (OR=5.416; 95% CI, 3.259-8.99; p<0.001). The decision to come to the ED without visiting a primary care physician was made more often by parents with a higher income (OR=2.153; 95% CI, 1.167-3.97) and those who came due to children having rash (OR=4.303; 95% CI, 1.089-16.995) or fever (OR=3.463; 95% CI, 1.01-11.876). Older parents were 2.07 (95% CI, 1.1224-3.506) times more likely to evaluate their child's health unfavorably than younger parents. CONCLUSIONS We identified predisposing, enabling, and need factors that influenced the parents' decision to bring their child to the ED for minor health problems that could be managed by a primary care physician. Parents assessed their child's condition more critically and thought that their child required urgent medical aid more frequently than healthcare professionals.

The impact of IgM deposits on the outcome of Nephrotic syndrome in children.

BACKGROUND: The significance of IgM deposits in glomerular mesangium has been controversial since they were first described due to the variations in the both the definitions used and described impact on clinical outcome. The aim of our study was to evaluate the significance of the IgM deposits in the glomerular mesangium for outcomes of nephrotic syndrome (NS) in children. METHODS: Forty-five children with NS who underwent renal biopsy at tertiary pediatric hospital from January 1st, 2000 to December 31st, 2015 and the pathology diagnosis of minimal change disease, focal segmental glomerulosclerosis and mesangial hypercellularity (MH) were retrospectively analyzed. IgM positivity was defined as ≥1+ imunofluorescence with predominantly mesangial distribution. The patients were stratified into IgM-positive (n = 18) and IgM-negative (n = 27). RESULTS: At the end of the median follow-up 4.5 years (range 0.17-13.14), the IgM-positive group was represented by 11 patients (61.1%) in remission, 3 patients (16.7%) with active disease and normal kidney function, 2 (11.1%) patients with active disease and impaired kidney function, 2 (11.1%) patients on renal replacement therapy. Accordingly, the IgM-negative group included 13 patients (48.1%) in remission, 12 (44.4%) with active disease and normal kidney function, 1 (3.7%) with active disease and impaired kidney function, 1 (3.7%) on renal replacement therapy, with no statistical significance between groups (p = 0.186). CONCLUSIONS: This study did not reveal significant differences of the disease outcomes between IgM-positive and IgM-negative groups.

Unscheduled return visits to a pediatric emergency department.

BACKGROUND AND OBJECTIVE: Return visits (RVs) to a pediatric emergency department (ED) within a short period after discharge have an influence on overcrowding of the ED and reveal some weaknesses of the health care system. The aim of this study was to determine the rate of RVs and factors related to RVs to the pediatric ED in Lithuania. MATERIALS AND METHODS: A retrospective study in an urban, tertiary-level teaching hospital was carried out. Electronic medical records of all patients (n=44097) visiting the ED of this hospital between 1 January and 31 December 2013 were analyzed. Demographic and clinical characteristics of patients who return to the ED within 72h and those who had not visited the ED were compared. Factors associated with RVs were determined by multivariable logistic regression. RESULTS: Of the overall ED population, 33889 patients were discharged home after the initial assessment. A total of 1015 patients returned to the ED within 72h, giving a RV rate of 3.0%. Being a 0-7-year old, visiting the ED during weekdays, having a GP referral, receiving of laboratory tests and ultrasound on the initial visit were associated with greater likelihoods of returning to the ED. Patients who arrived to the ED from 8:01a.m. to 4:00p.m. and underwent radiological test were less likely to return to the ED within 72h. Diseases such as gastrointestinal disorders or respiratory tract/earth-nose-throat (ENT) diseases and symptoms such as fever or pain were significantly associated with returning to the ED. The initial diagnosis corresponded to the diagnosis made on the second visit for only 44.1% of the patients, and the highest rate of the congruity in diagnosis was for injuries/poisoning, surgical pathologies (77.2%) and respiratory tract diseases (76.9%). CONCLUSIONS: RVs accounted for only a small proportion of visits to the ED. RVs were more prevalent among younger patients and patients with a GP referral as well as performed more often after discharging from the ED in the evening and at night.

Population-Based Screening for Selective Immunoglobulin A (IgA) Deficiency in Lithuanian Children Using a Rapid Antibody-Based Fingertip Test.

BACKGROUND Selective immunoglobulin A (IgA) deficiency is the most common inherited immunodeficiency disorder worldwide. An early diagnosis is advocated because of the increased risk of infections, autoimmune diseases, and allergic reactions. We investigated the usefulness of a rapid point-of-care test in detecting for IgA deficiency in a population with a previously unknown prevalence. MATERIAL AND METHODS Altogether, 1000 children aged 11-13 years from randomly selected Lithuanian schools were enrolled. A point-of-care test with a fingertip sample was used to screen for the presence of IgA deficiency in children whose parents gave consent. Those with suspected IgA deficiency were referred to hospital for further clinical examination and confirmation of the diagnosis. In addition, their medical histories were compared with those of 30 age- and sex-matched healthy controls. RESULTS IgA deficiency was suspected in one girl and in three boys on the basis of the rapid test, and the diagnosis was confirmed for all four cases (prevalence 0.4%, 95% confidence interval 0.16-1.02%). There was no difference in disease history or complications between IgA-deficient children and healthy controls. CONCLUSIONS The rapid antibody test is a practical and accurate method to diagnose selective IgA deficiency in children. The prevalence of IgA deficiency among Lithuanian schoolchildren is 1:250.

Pleuro-peritoneal or pericardio-peritoneal leak in children on chronic peritoneal dialysis-A survey from the European Paediatric Dialysis Working Group.

BACKGROUND: Pleural or pericardial effusions secondary to pleuro-peritoneal fistula (PPF) and pericardio-peritoneal fistula (PcPF) are rare but serious complications of peritoneal dialysis (PD). METHODS: We conducted a 10-year survey across all participating centres in the European Paediatric Dialysis Working Group to review the incidence, diagnostic techniques, therapeutic options and outcome of children on chronic PD with PPF and/or PcPF. RESULTS: Of 1506 children on PD there were ten cases (8 of PPF, 1 each of PcPF and PPF + PcPF), with a prevalence of 0.66%. The median age at presentation was 1.5 [inter-quartile range (IQR) 0.4-2.4] years, and nine children were <3 years. The time on PD before onset of symptoms was 4.3 (IQR 1.3-19.8) months. Eight children had herniae and seven had abdominal surgery in the preceding 4 weeks. Symptoms at presentation were respiratory distress, reduced ultrafiltration and tachycardia. PD was stopped in all children; three were managed conservatively and thoracocentesis was performed in seven (with pleurodesis in 3). PD was restarted in only three children, in two of them with success. CONCLUSION: In conclusion, PPF and PcPF are rare in children on chronic PD, but are associated with significant morbidity, requiring a change of dialysis modality in all cases. Risk factors for PPF development include age of <3 years, herniae and recent abdominal surgery.

Physical Activity and Sedentary Screen Time in Obese and Overweight Children Living in Different Environments.

AIM: To assess the relationship of children's physical activity and sedentary screen time with overweight and obesity in children living in different environments (town and city) in Lithuania. METHODS: An analysis of anthropometric data from 532 children living in town and city areas was performed. A youth physical activity questionnaire (YPAQ) was conducted to evaluate physical activity and sedentary screen time. RESULTS: The prevalence of overweight and obesity among the children was 25.5% in the town and 18.6% in the city. Children living in the town on average engaged 9.3 min/day less in moderate to vigorous physical activity (p=0.050) and had 33.2 MET-min/day lower energy expenditure than children living in the city. Sedentary screen time was extremely high on weekends in both town and city children. CONCLUSIONS: A higher prevalence of overweight and obesity and a lower amount of moderate-to-vigorous physical activity was found in children living in the town compared to children living in the city.

Long-term follow-up of children with typical hemolytic uremic syndrome.

OBJECTIVE: The aim of the study was to determine the associations of the acute period course with late-emerging sequelae in children with typical hemolytic uremic syndrome (HUS). MATERIALS AND METHODS: The data of 62 children with typical HUS during the acute phase were retrospectively analyzed by age, sex, duration of anuria/oliguria, method and duration of renal replacement therapy, proteinuria, hypertension, and renal function. The data of 33 children at 10-year follow-up after the onset of the disease were evaluated for changes in hypertension, proteinuria, and renal function. RESULTS: In the acute phase of the disease (n=62), hypertension was documented in 75.8% of the children; proteinuria, in 85.5%; and renal dysfunction, in 100%. At 10 years after the onset of the disease (n=33), hypertension was documented in 12.1%, 6.1%, and 24.2% at 1-, 5-, and ≥10-year follow-ups, respectively, and more often in children aged <1 year at the onset of the disease. Proteinuria was found in 15.2%, 9.1%, and 33.3% of the patients, respectively. After ≥10 years, hypertension developed for the first time in 6.1% of the patients. Renal injury of varying degrees was seen in 15.2% of the children at the 1-year follow-up, and after ≥10 years the proportion increased to 33.3%. CONCLUSIONS: At 10 years after the acute phase of typical HUS in children, the prevalence of hypertension and proteinuria at 1- and 5-year follow-ups decreased, but after 10 years it started to increase. As much as 6.1% of the children developed hypertension or proteinuria for the first time at 10 years. Hypertension was documented more frequently in children who were younger than <1 year at the onset of the disease. Renal dysfunction after 5 and 10 years remained in more than one-third of cases, and it was observed more often if hypertension was documented at the acute period.

Clinical practice recommendations for primary hyperoxaluria: an expert consensus statement from ERKNet and OxalEurope.

Primary hyperoxaluria (PH) is an inherited disorder that results from the overproduction of endogenous oxalate, leading to recurrent kidney stones, nephrocalcinosis and eventually kidney failure; the subsequent storage of oxalate can cause life-threatening systemic disease. Diagnosis of PH is often delayed or missed owing to its rarity, variable clinical expression and other diagnostic challenges. Management of patients with PH and kidney failure is also extremely challenging. However, in the past few years, several new developments, including new outcome data from patients with infantile oxalosis, from transplanted patients with type 1 PH (PH1) and from patients with the rarer PH types 2 and 3, have emerged. In addition, two promising therapies based on RNA interference have been introduced. These developments warrant an update of existing guidelines on PH, based on new evidence and on a broad consensus. In response to this need, a consensus development core group, comprising (paediatric) nephrologists, (paediatric) urologists, biochemists and geneticists from OxalEurope and the European Rare Kidney Disease Reference Network (ERKNet), formulated and graded statements relating to the management of PH on the basis of existing evidence. Consensus was reached following review of the recommendations by representatives of OxalEurope, ESPN, ERKNet and ERA, resulting in 48 practical statements relating to the diagnosis and management of PH, including consideration of conventional therapy (conservative therapy, dialysis and transplantation), new therapies and recommendations for patient follow-up.

Identification of 27 Novel Variants in Genes COL4A3, COL4A4, and COL4A5 in Lithuanian Families With Alport Syndrome.

Introduction: Alport syndrome (AS) is an inherited disorder characterized by hematuria, proteinuria, and kidney function impairment, and frequently associated with extrarenal manifestations. Pathogenic variants in COL4A5 usually cause X-linked Alport syndrome (XLAS), whereas those in the COL4A3 or COL4A4 genes are associated with autosomal dominant (AD) or recessive (AR) inheritance. To date, more than 3000 different disease-causing variants in COL4A5, COL4A3, and COL4A4 have been identified. The aim of this study was to evaluate the clinical and genetic spectrum of individuals with novel, pathogenic or likely pathogenic variants in the COL4A3-A5 genes in a previously unstudied cohort. Methods: In this study molecular analysis by next generation sequencing (NGS) was performed on individuals from a Lithuanian cohort, with suspected AS. The presence of AS was assessed by reviewing clinical evidence of hematuria, proteinuria, chronic kidney disease (CKD), kidney failure (KF), a family history of AS or persistent hematuria, and specific histological lesions in the kidney biopsy such as thinning or lamellation of the glomerular basement membrane (GBM). Clinical, genetic, laboratory, and pathology data were reviewed. The novelty of the COL4A3-A5 variants was confirmed in the genetic variant databases (Centogene, Franklin, ClinVar, Varsome, InterVar). Only undescribed variants were included in this study. Results: Molecular testing of 171 suspected individuals led to the detection of 99 individuals with 44 disease causing variants including 27, previously undescribed changes, with the frequency of 9/27 (33,3%) in genes COL4A5, COL4A3 and COL4A4 equally. Three individuals were determined as having digenic AS causing variants: one in COL4A3 and COL4A4, two in COL4A4 and COL4A5. The most prevalent alterations in genes COL4A3-5 were missense variants (n = 19), while splice site, frameshift, unknown variant and stop codon changes were detected more in genes COL4A4 and COL4A5 and accounted for 3, 3, 1 and 1 of all novel variants, respectively. Conclusion: Genotype-phenotype correlation analysis suggested that some variants demonstrated intra-familial phenotypic variability. These novel variants represented more than half of all the variants found in a cohort of 171 individuals from 109 unrelated families who underwent testing. Our study expands the knowledge of the genetic and phenotypic spectrum for AS.

The landscape of Mucopolysaccharidosis in Southern and Eastern European countries: a survey from 19 specialistic centers.

BACKGROUND: Mucopolysaccharidoses (MPS) are a group of lysosomal storage disorders caused by defects in genes coding for different lysosomal enzymes which degrade glycosaminoglycans. Impaired lysosomal degradation causes cell dysfunction leading to progressive multiorgan involvement, disabling consequences and poor life expectancy. Enzyme replacement therapy (ERT) is now available for most MPS types, offering beneficial effects on disease progression and improving quality of life of patients. The landscape of MPS in Europe is not completely described and studies on availability of treatment show that ERT is not adequately implemented, particularly in Southern and Eastern Europe. In this study we performed a survey analysis in main specialist centers in Southern and Eastern European countries, to outline the picture of disease management in the region and understand ERT implementation. Since the considerable number of MPS IVA patients in the region, particularly adults, the study mainly focused on MPS IVA management and treatment. RESULTS: 19 experts from 14 Southern and Eastern European countries in total responded to the survey. Results outlined a picture of MPS management in the region, with a high number of MPS patients managed in the centers and a high level of care. MPS II was the most prevalent followed by MPS IVA, with a particular high number of adult patients. The study particularly focused on management and treatment of MPS IVA patients. Adherence to current European Guidelines for follow-up of MPS IVA patients is generally adequate, although some important assessments are reported as difficult due to the lack of MPS skilled specialists. Availability of ERT in Southern and Eastern European countries is generally in line with other European regions, even though regulatory, organizational and reimbursement constrains are demanding. CONCLUSIONS: The landscape of MPS in Southern and Eastern European countries is generally comparable to that of other European regions, regarding epidemiology, treatment accessibility and follow up difficulties. However, issues limiting ERT availability and reimbursement should be simplified, to start treatment as early as possible and make it available for more patients. Besides, educational programs dedicated to specialists should be implemented, particularly for pediatricians, clinical geneticists, surgeons, anesthesiologists and neurologists.

An integrated multiomic approach as an excellent tool for the diagnosis of metabolic diseases: our first 3720 patients.

To present our experience using a multiomic approach, which integrates genetic and biochemical testing as a first-line diagnostic tool for patients with inherited metabolic disorders (IMDs). A cohort of 3720 patients from 62 countries was tested using a panel including 206 genes with single nucleotide and copy number variant (SNV/CNV) detection, followed by semi-automatic variant filtering and reflex biochemical testing (25 assays). In 1389 patients (37%), a genetic diagnosis was achieved. Within this cohort, the highest diagnostic yield was obtained for patients from Asia (57.5%, mainly from Pakistan). Overall, 701 pathogenic/likely pathogenic unique SNVs and 40 CNVs were identified. In 620 patients, the result of the biochemical tests guided variant classification and reporting. Top five diagnosed diseases were: Gaucher disease, Niemann-Pick disease type A/B, phenylketonuria, mucopolysaccharidosis type I, and Wilson disease. We show that integrated genetic and biochemical testing facilitated the decision on clinical relevance of the variants and led to a high diagnostic yield (37%), which is comparable to exome/genome sequencing. More importantly, up to 43% of these patients (n = 610) could benefit from medical treatments (e.g., enzyme replacement therapy). This multiomic approach constitutes a unique and highly effective tool for the genetic diagnosis of IMDs.

Guidelines for Genetic Testing and Management of Alport Syndrome.

Genetic testing for pathogenic COL4A3-5 variants is usually undertaken to investigate the cause of persistent hematuria, especially with a family history of hematuria or kidney function impairment. Alport syndrome experts now advocate genetic testing for persistent hematuria, even when a heterozygous pathogenic COL4A3 or COL4A4 is suspected, and cascade testing of their first-degree family members because of their risk of impaired kidney function. The experts recommend too that COL4A3 or COL4A4 heterozygotes do not act as kidney donors. Testing for variants in the COL4A3-COL4A5 genes should also be performed for persistent proteinuria and steroid-resistant nephrotic syndrome due to suspected inherited FSGS and for familial IgA glomerulonephritis and kidney failure of unknown cause.

Consensus statement on standards and guidelines for the molecular diagnostics of Alport syndrome: refining the ACMG criteria.

The recent Chandos House meeting of the Alport Variant Collaborative extended the indications for screening for pathogenic variants in the COL4A5, COL4A3 and COL4A4 genes beyond the classical Alport phenotype (haematuria, renal failure; family history of haematuria or renal failure) to include persistent proteinuria, steroid-resistant nephrotic syndrome, focal and segmental glomerulosclerosis (FSGS), familial IgA glomerulonephritis and end-stage kidney failure without an obvious cause. The meeting refined the ACMG criteria for variant assessment for the Alport genes (COL4A3-5). It identified 'mutational hotspots' (PM1) in the collagen IV α5, α3 and α4 chains including position 1 Glycine residues in the Gly-X-Y repeats in the intermediate collagenous domains; and Cysteine residues in the carboxy non-collagenous domain (PP3). It considered that 'well-established' functional assays (PS3, BS3) were still mainly research tools but sequencing and minigene assays were commonly used to confirm splicing variants. It was not possible to define the Minor Allele Frequency (MAF) threshold above which variants were considered Benign (BA1, BS1), because of the different modes of inheritances of Alport syndrome, and the occurrence of hypomorphic variants (often Glycine adjacent to a non-collagenous interruption) and local founder effects. Heterozygous COL4A3 and COL4A4 variants were common 'incidental' findings also present in normal reference databases. The recognition and interpretation of hypomorphic variants in the COL4A3-COL4A5 genes remains a challenge.