Examination of Subbasal Nerve Plexus and Central Corneal Stromal Microstructure in Subjects With Congenital Aniridia, Using in Vivo Confocal Laser Scanning Microscopy.

PURPOSE: During life up to 70% of aniridia subjects develop aniridia-associated keratopathy (AAK). AAK is characterized by limbal stem cell insufficiency, impaired corneal epithelial cell differentiation and abnormal cell adhesion, which leads to centripetal spreading vascularization, conjunctivalization, and thickening of the cornea. Our aim was to examine the subbasal nerve plexus and central corneal stromal microstructure in subjects with congenital aniridia, using in vivo confocal laser scanning microscopy CLSM. METHODS: 31 eyes of 18 patients (55.6% males, mean age: 25.22 ± 16.35 years) with congenital aniridia and 46 eyes of 29 healthy subjects (41.4% males, mean age 30 ± 14.82 years) were examined using the Rostock Cornea Module of Heidelberg Retina Tomograph-III. At the subbasal nerve plexus, corneal nerve fiber density (CNFD), corneal nerve fiber length (CNFL), corneal total branch density (CTBD), and corneal nerve fiber width (CNFW) were analyzed using ACCMetrics software. Keratocyte density in the anterior, middle and posterior stroma was assessed manually. RESULTS: The CNFD (2.02 ± 4.08 vs 13.99 ± 6.34/mm2), CNFL (5.78 ± 2.68 vs 10.56 ± 2.82 mm/mm2) and CTBD (15.08 ± 15.62 vs 27.44 ± 15.05/mm2) were significantly lower in congenital aniridia subjects than in controls (p < 0.001 for all). CNFW was significantly higher in aniridia subjects than in controls (0.03 ± 0.004 vs 0.02 ± 0.003 mm/mm2) (p = 0.003). Keratocyte density was significantly lower in all stromal layers of aniridia subjects than in controls (p < 0.001 for all). Stromal alterations included confluent keratocytes, keratocytes with long extensions and hyperreflective dots between keratocytes in aniridia. CONCLUSIONS: Decrease in CNFD, CNFL, and CTBD, as well as increase in CNFW well refer to the congenital aniridia-associated neuropathy. The decreased keratocyte density and the stromal alterations may be related to an increased cell death in congenital aniridia, nevertheless, stromal changes in different stages of AAK have to be further analyzed in detail.

Throwing off the keratin chains: a potential therapy for hereditary podocytopathy.

In the current issue, Kuzmuk et al. offer a therapeutic option for patients with NPHS2 R138Q-associated nephrotic syndrome. For the first time in hereditary podocytopathies, this is offered by restoring the membrane targeting of a pathogenic protein. The idea that it is enough to liberate podocin from the trap of keratin 8, a key member of endoplasmic-reticulum-associated protein degradation complex, was brilliantly recognized based on former results obtained in cystic fibrosis.

Multicenter Long-Term Real World Data on Treatment With Lumasiran in Patients With Primary Hyperoxaluria Type 1.

Introduction: The RNA interference (RNAi) medication lumasiran reduces hepatic oxalate production in primary hyperoxaluria type 1 (PH1). Data outside clinical trials are scarce. Methods: We report on retrospectively and observationally obtained data in 33 patients with PH1 (20 with preserved kidney function, 13 on dialysis) treated with lumasiran for a median of 18 months. Results: Among those with preserved kidney function, mean urine oxalate (Uox) decreased from 1.88 (baseline) to 0.73 mmol/1.73 m2 per 24h after 3 months, to 0.72 at 12 months, and to 0.65 at 18 months, but differed according to vitamin B6 (VB6) medication. The highest response was at month 4 (0.55, -70.8%). Plasma oxalate (Pox) remained stable over time. Glomerular filtration rate increased significantly by 10.5% at month 18. Nephrolithiasis continued active in 6 patients, nephrocalcinosis ameliorated or progressed in 1 patient each. At last follow-up, Uox remained above 1.5 upper limit of normal (>0.75 mmol/1.73 m2 per 24h) in 6 patients. Urinary glycolate (Uglyc) and plasma glycolate (Pglyc) significantly increased in all, urine citrate decreased, and alkali medication needed adaptation. Among those on dialysis, mean Pox and Pglyc significantly decreased and increased, respectively after monthly dosing (Pox: 78-37.2, Pglyc: 216.4-337.4 µmol/l). At quarterly dosing, neither Pox nor Pglyc were significantly different from baseline levels. An acid state was buffered by an increased dialysis regimen. Systemic oxalosis remained unchanged. Conclusion: Lumasiran treatment is safe and efficient. Dosage (interval) adjustment necessities need clarification. In dialysis, lack of Pox reduction may relate to dissolving systemic oxalate deposits. Pglyc increment may be a considerable acid load requiring careful consideration, which definitively needs further investigation.

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.

The dominant findings of a recessive man: from Mendel's kid pea to kidney.

The research of Mendel, born two centuries ago, still has many direct implications for our everyday clinical work. He introduced the terms "dominant" and "recessive" characters and determined their 3:1 ratio in the offspring of heterozygous "hybrid" plants. This distribution allowed calculation of the number of the phenotype-determining "elements," i.e., the alleles, and has been used ever since to prove the monogenic origin of a disorder. The Mendelian inheritance of monogenic kidney disorders is still of great help in distinguishing them from those with multifactorial origin in clinical practice. Inheritance of most monogenic kidney disorders fits to Mendel's observations: the equal contribution of the two parents and the complete penetrance or the direct correlation between the frequency of the recessive character and the degree of inbreeding. Nevertheless, beyond the truth of these basic concepts, several observations have expanded their genetic characteristics. The extreme genetic heterogeneity, the pleiotropy of the causal genes and the role of modifiers in ciliopathies, the digenic inheritance and parental imprinting in some tubulopathies, and the incomplete penetrance and eventual interallelic interactions in podocytopathies, reflect this expansion. For all these reasons, the transmission pattern in a natural setting may depend not only on the "character" but also on the causal gene and the variant. Mendel's passion for research combined with his modest personality and meticulous approach can still serve as an example in the work required to understand the non-Mendelian universe of genetics.

[Congenital aniridia patients' experience on their visual impairment in Hungary.] / Veleszületett aniridiás betegek látáskárosodással kapcsolatos tapasztalatai Magyarországon.

INTRODUCTION: Aniridia is a rare congenital panocular disease associated with varying degrees of visual acuity impairment. OBJECTIVE: To assess the experiences of congenital aniridia patients in Hungary, with visual impairment using a questionnaire developed by the ANIRIDIA-NET. PATIENTS AND METHOD: Patients completed the Hungarian version of the 20-item ANIRIDIA-NET questionnaire with our assistance. The questionnaire covered demographic data, the most common complaints caused by the disease, the difficulties caused by low vision in different life situations and the frequency of low vision aids used in daily life. RESULTS: 33 subjects (17 female [51.51%] and 16 male [48.48%]), 16 (48.5%) children and 17 (51.5%) adults completed the questionnaire, with an age of 25.69 ± 17.49 years (5-59 years). Daily photosensitivity was reported by 27 (81.8%), dry eyes by 5 (15.2%), tearing by 4 (12.1%), fluctuating vision by 3 (9.1%), and eye pain by 2 (6.1%) subjects. The majority of respondents said that personal communication with schoolmates (16 [48.5%]) or colleagues at work (11 [33.3%]) never caused difficulties because of their visual impairment. 29 people (87.9%) never needed help with daily routines at home, 24 (72.7%) with getting to school/work and 17 (51.5%) with various activities. 29 people (87.8%) never used low vision aids for communication, 23 (69.7%) for travelling, 20 (60.6%) for participating in social activities, 18 (54.5%) for studying/work. CONCLUSION: Although aniridia is associated with reduced visual acuity, the majority of people with congenital aniridia, especially in childhood, manage to cope with personal communication and various life situations without difficulty, despite their eye complaints. Low vision aids can be an important aid for them as they grow into adulthood and as they age. Orv Hetil. 2023; 164(34): 1342-1349.

[Staging of aniridia-associated keratopathy]. / Az aniridiához társult keratopathia stádiumbeosztása.

INTRODUCTION: Congenital aniridia is a rare panocular disease that affects almost all eye structures leading in most patients to reduced visual acuity. Ophthalmological signs include aniridia-associated keratopathy, secondary glaucoma, cataract, macular and optic nerve head hypoplasia, nystagmus. Although the term aniridia-associated keratopathy has long been used in the literature, various staging proposals have been described. OBJECTIVE: To analyze aniridia-associated keratopathy stages, using available literature classifications, in patients with aniridia in Hungary. PATIENTS AND METHODS: We examined 65 eyes of 33 patients with congenital aniridia (age: 25.69 ± 17.49 [5-59] years, 17 females [51.51%]). We recorded the corneal status by slit-lamp examination and classified the corneal abnormalities according to the Mackman, Mayer, López-García and Lagali staging. RESULTS: According to Mackman's classification, 8 eyes (12.3%) were in stage 0, 0 eye in stage 1A, 38 eyes (58.46%) in stage 1B and 19 eyes (29.23%) in stage 2. According to Mayer, stage I included 8 eyes (12.3%), stage II 38 eyes (58.46%), stage III 5 eyes (7.7%), stage IV 7 eyes (10.77%) and stage V 7 eyes (10.77%). In López-García's classification, 8 eyes (12.3%) could not be grouped, 20 eyes (30.77%) were in stage 1, 18 eyes (27.7%) in stage 2 and 19 eyes (29.3%) in stage 3. Lagali's classification included 8 eyes (12.3%) in stage 0, 20 eyes (30.77%) in stage 1, 18 eyes (27.7%) in stage 2, 5 eyes (7.7%) in stage 3 and 14 eyes (21.54%) in stage 4. CONCLUSION: We recommend using Lagali's staging scheme for aniridia-associated keratoptahy due to its ease of use, detailed progression assessment, and treatment planning. In stage 1 according to Lagali, blood vessels cross the limbus by up to 1 mm, in stage 2 the central 2-3 mm of the corneal area is spared of blood vessels. When the blood vessels reach the center of the cornea, it is stage 3, followed by opaque, uneven corneal pannus in stage 4. Orv Hetil. 2023; 164(27): 1063-1069.

The genetic landscape and clinical spectrum of nephronophthisis and related ciliopathies.

Nephronophthisis (NPH) is an autosomal-recessive ciliopathy representing one of the most frequent causes of kidney failure in childhood characterized by a broad clinical and genetic heterogeneity. Applied to one of the worldwide largest cohorts of patients with NPH, genetic analysis encompassing targeted and whole exome sequencing identified disease-causing variants in 600 patients from 496 families with a detection rate of 71%. Of 788 pathogenic variants, 40 known ciliopathy genes were identified. However, the majority of patients (53%) bore biallelic pathogenic variants in NPHP1. NPH-causing gene alterations affected all ciliary modules defined by structural and/or functional subdomains. Seventy six percent of these patients had progressed to kidney failure, of which 18% had an infantile form (under five years) and harbored variants affecting the Inversin compartment or intraflagellar transport complex A. Forty eight percent of patients showed a juvenile (5-15 years) and 34% a late-onset disease (over 15 years), the latter mostly carrying variants belonging to the Transition Zone module. Furthermore, while more than 85% of patients with an infantile form presented with extra-kidney manifestations, it only concerned half of juvenile and late onset cases. Eye involvement represented a predominant feature, followed by cerebellar hypoplasia and other brain abnormalities, liver and skeletal defects. The phenotypic variability was in a large part associated with mutation types, genes and corresponding ciliary modules with hypomorphic variants in ciliary genes playing a role in early steps of ciliogenesis associated with juvenile-to-late onset NPH forms. Thus, our data confirm a considerable proportion of late-onset NPH suggesting an underdiagnosis in adult chronic kidney disease.

The importance of pseudouridylation: human disorders related to the fifth nucleoside.

Pseudouridylation is one of the most abundant RNA modifications in eukaryotes, making pseudouridine known as the "fifth nucleoside." This highly conserved alteration affects all non-coding and coding RNA types. Its role and importance have been increasingly widely researched, especially considering that its absence or damage leads to serious hereditary diseases. Here, we summarize the human genetic disorders described to date that are related to the participants of the pseudouridylation process.

[Congenital aniridia - Hungarian data of a spectrum disease]. / Congenitalis aniridia ­ egy spektrumbetegség magyarországi adatai.

INTRODUCTION: Congenital aniridia is a rare disease, characterised by the complete or partial absence of the iris, but lesions may be present in all structures of the eye. OBJECTIVE: To determine the prevalence of ocular diseases in congenital aniridia by analyzing patients from a Hungarian centre. PATIENTS AND METHODS: Patients at the Department of Ophthalmology of Semmelweis University, examined between October 2005 and May 2022, have been included. After taking the patients' medical history, a detailed ophthalmological examination has been performed. RESULTS: Of the 82 patients in the database, 33 (age 25.69 ± 17.49 [5-59] years, 17 females [51.51%]) presented for examination and 65 eyes were examined. Nystagmus was found in 45 eyes of 23 patients (69.23%), and the patients' uncorrected distance visual acuity was 0.14 ± 0.128 (0.9 logMAR; 0.63-0.005). The aniridia-associated keratopathy was Grade 0 in 8 eyes (12.3%), Grade 1 in 10 eyes (15.38%), Grade 2 in 16 eyes (24.62%), Grade 3 in 4 eyes (6.15%) and Grade 4 in 25 eyes (38.46%). 30 eyes (46.15%) of 15 patients had secondary glaucoma, 6 eyes (9.2%) of 3 patients were glaucoma suspect. 8 eyes (12.3%) had a clear lens, 44 eyes (67.69%) had cataract, of which 22 (33.84%) were anterior cortical polar cataracts. 13 eyes (20%) were pseudophakic (PCL) and 7 eyes (10.77%) had lens dislocation or zonular insufficiency. Macular hypoplasia was found in 6 eyes of 3 patients (4.6%) and optic nerve head malformation in 2 eyes of 1 patient (3.03%). CONCLUSION: The ocular signs of congenital aniridia are aniridia-associated keratopathy, secondary glaucoma, cataract, macular and optic nerve head hypoplasia. Systematic collaboration of different ophthalmological specialties is required for the management and care of all these ocular abnormalities. Orv Hetil. 2023; 164(4): 148-155.

The pathogenic c.1171A>G (p.Arg391Gly) and c.2359G>A (p.Val787Ile) ABCC6 variants display incomplete penetrance causing pseudoxanthoma elasticum in a subset of individuals.

ABCC6 promotes ATP efflux from hepatocytes to bloodstream. ATP is metabolized to pyrophosphate, an inhibitor of ectopic calcification. Pathogenic variants of ABCC6 cause pseudoxanthoma elasticum, a highly variable recessive ectopic calcification disorder. Incomplete penetrance may initiate disease heterogeneity, hence symptoms may not, or differently manifest in carriers. Here, we investigated whether incomplete penetrance is a source of heterogeneity in pseudoxanthoma elasticum. By integrating clinical and genetic data of 589 patients, we created the largest European cohort. Based on allele frequency alterations, we identified two incomplete penetrant pathogenic variants, c.2359G>A (p.Val787Ile) and c.1171A>G (p.Arg391Gly), with 6.5% and 2% penetrance, respectively. However, when penetrant, the c.1171A>G (p.Arg391Gly) manifested a clinically unaltered severity. After applying in silico and in vitro characterization, we suggest that incomplete penetrant variants are only deleterious if a yet unknown interacting partner of ABCC6 is mutated simultaneously. The low penetrance of these variants should be contemplated in genetic counseling.

Arthrogryposis­renal dysfunction­cholestasis syndrome / Arthrogryposis-renalis diszfunkció-cholestasis szindróma.

Összefoglaló. Az arthrogryposis-renalis diszfunkció-cholestasis (ARC) szindróma igen rossz prognózisú autoszomális recesszív kórkép. A három vezeto tünethez társulhat központi idegrendszeri érintettség, siketség, cardiovascularis anomália (pitvari és kamrai sövényhiány), thrombocytafunkció-zavar, rekurrens szepszisek, ichthyosis, valamint súlyfejlodésben való elmaradás. A háromnapos újszülöttet neuromuscularis betegség gyanúja miatt vettük át a szülészeti intézménybol. Fizikális vizsgálat során pes equinovarust és hypotrophiás küllemet tapasztaltunk. Kéthetes korában súlyos tubulopathia, valamint cholestasis igazolódott normális gamma-glutamil-transzferáz-szint mellett. A perifériás vérkenet vizsgálata során abnormális morfológiájú thrombocyták ábrázolódtak. Súlygyarapodást komplex felépített enteralis és parenteralis táplálás segítségével sem sikerült elérni. Három hónapos korára a gyermek súlya 15%-kal a születési súlya alatt volt. A kórkép szövodményeként ismétlodo bakteriális véráramfertozés súlyosbította az állapotát. Az újszülött klinikai képe az ARC-szindrómának felelt meg. A kóroki gének szekvenálása során a VPS33B-génben homozigóta c.498+1G>T variáns igazolódott, mely igazolja a betegség fennállását. Orv Hetil. 2022; 163(2): 74-78. Summary. Arthrogryposis-renal dysfunction-cholestasis (ARC) syndrome is an autosomal recessive multisystem disorder that typically presents with arthrogryposis, renal tubular leak and neonatal cholestatic jaundice. It can be accompanied by nervous system abnormalities, deafness, structural cardiac defects, abnormal platelet morphology, recurrent sepsis, ichthyosis and failure to thrive. The three-day-old neonate was admitted for a suspected neuromuscular disorder. On examination, clubfoot, jaundice and hypotonia were found. Laboratory evaluation revealed tubulopathy and cholestasis with normal gamma-glutamyl transferase level. Peripheral blood smear evaluation revealed abnormally giant platelets. Despite the combined enteral and parenteral nutrition, the infant experienced severe failure to thrive. The phenotype of the presented neonate is consistent with ARC syndrome. Sequencing of the causal genes revealed a homozygous consensus splice site VPS33B mutation (c.498+1G>T), confirming the clinical diagnosis. Orv Hetil. 2022; 163(2): 74-78.

Identification of incompletely penetrant variants and interallelic interactions in autosomal recessive disorders by a population-genetic approach.

We aimed to identify incompletely penetrant (IP) variants and interallelic interactions in autosomal recessive disorders by a population-genetic approach. Genotype and clinical data were collected from 9038 patients of European origin with ASL, ATP7B, CAPN3, CFTR, CTNS, DHCR7, GAA, GALNS, GALT, IDUA, MUT, NPHS1, NPHS2, PAH, PKHD1, PMM2, or SLC26A4-related disorders. We calculated the relative allele frequency of each pathogenic variant (n = 1936) to the loss-of-function (LOF) variants of the corresponding gene in the patient ( ACptV/ACptLOF ) and the general population ( ACgnomADV/ACgnomADLOF ) and estimated the penetrance of each variant by calculating their ratio: (ACptV/ACptLOF)(ACgnomADV/ACgnomADLOF) (V/LOF ratio). We classified all variants as null or hypomorphic based on the associated clinical phenotype. We found 25 variants, 29% of the frequent 85 variants, to be underrepresented in the patient population (V/LOF ratio <30% with p < 7.22 × 10-5 ), including 22 novel ones in the ASL, CAPN3, CFTR, GAA, GALNS, PAH, and PKHD1 genes. In contrast to the completely penetrant variants (CP), the majority of the IP variants were hypomorphic (IP: 16/18, 88%; CP: 177/933, 19.0%; p = 5.12 × 10-10 ). Among them, only the NPHS2 R229Q variant was subject to interallelic interactions. The proposed algorithm identifies frequent IP variants and estimates their penetrance and interallelic interactions in large patient cohorts.

Diagnosis and treatment of paediatric multisystem inflammatory syndrome / A gyermekkori koronavírus-fertozést követo sokszervi gyulladás diagnosztikája és kezelése.

Összefoglaló. A SARS-CoV-2-fertozés ritka gyermekkori szövodménye a sokszervi gyulladás, angol terminológiával paediatric inflammatory multisystem syndrome (PIMS). Két vagy több szerv érintettségével járó, súlyos tünetekkel induló betegségrol van szó, amelynek tünetei átfedést mutatnak a Kawasaki-betegséggel, a toxikus sokk szindrómával és a makrofágaktivációs szindrómával. A PIMS-betegek intenzív terápiás osztályon vagy intenzív terápiás háttérrel rendelkezo intézményben kezelendok, ahol biztosítottak a kardiológiai ellátás feltételei is. A szükséges immunterápia a klinikai prezentációtól függ. A jelen közleményben a szerzok a releváns nemzetközi irodalom áttekintését követoen ajánlást tesznek a PIMS diagnosztikai és terápiás algoritmusára. Orv Hetil. 2021; 162(17): 652-667. Summary. Pediatric inflammatory multisystem syndrome (PIMS) is a rare complication of SARS-CoV-2 infection in children. PIMS is a severe condition, involving two or more organ systems. The symptoms overlap with Kawasaki disease, toxic shock syndrome and macrophage activation syndrome. PIMS patients should be treated in an intensive care unit or in an institution with an intensive care background, where cardiological care is also provided. The required specific immunotherapy depends on the clinical presentation. In this paper, after reviewing the relevant international literature, the authors make a recommendation for the diagnostic and therapeutic algorithm for PIMS. Orv Hetil. 2021; 162(17): 652-667.

Clinical and genetic findings in Hungarian pediatric patients carrying chromosome 16p copy number variants and a review of the literature.

The short arm of chromosome 16 (16p) is enriched for segmental duplications, making it susceptible to recurrent, reciprocal rearrangements implicated in the etiology of several phenotypes, including intellectual disability, speech disorders, developmental coordination disorder, autism spectrum disorders, attention deficit hyperactivity disorders, obesity and congenital skeletal disorders. In our clinical study 73 patients were analyzed by chromosomal microarray, and results were confirmed by fluorescence in situ hybridization or polymerase chain reaction. All patients underwent detailed clinical evaluation, with special emphasis on behavioral symptoms. 16p rearrangements were identified in 10 individuals. We found six pathogenic deletions and duplications of the recurrent regions within 16p11.2: one patient had a deletion of the distal 16p11.2 region associated with obesity, while four individuals had duplications, and one patient a deletion of the proximal 16p11.2 region. The other four patients carried 16p variations as second-site genomic alterations, acting as possible modifying genetic factors. We present the phenotypic and genotypic results of our patients and discuss our findings in relation to the available literature.

An international cohort study of autosomal dominant tubulointerstitial kidney disease due to REN mutations identifies distinct clinical subtypes.

There have been few clinical or scientific reports of autosomal dominant tubulointerstitial kidney disease due to REN mutations (ADTKD-REN), limiting characterization. To further study this, we formed an international cohort characterizing 111 individuals from 30 families with both clinical and laboratory findings. Sixty-nine individuals had a REN mutation in the signal peptide region (signal group), 27 in the prosegment (prosegment group), and 15 in the mature renin peptide (mature group). Signal group patients were most severely affected, presenting at a mean age of 19.7 years, with the prosegment group presenting at 22.4 years, and the mature group at 37 years. Anemia was present in childhood in 91% in the signal group, 69% prosegment, and none of the mature group. REN signal peptide mutations reduced hydrophobicity of the signal peptide, which is necessary for recognition and translocation across the endoplasmic reticulum, leading to aberrant delivery of preprorenin into the cytoplasm. REN mutations in the prosegment led to deposition of prorenin and renin in the endoplasmic reticulum-Golgi intermediate compartment and decreased prorenin secretion. Mutations in mature renin led to deposition of the mutant prorenin in the endoplasmic reticulum, similar to patients with ADTKD-UMOD, with a rate of progression to end stage kidney disease (63.6 years) that was significantly slower vs. the signal (53.1 years) and prosegment groups (50.8 years) (significant hazard ratio 0.367). Thus, clinical and laboratory studies revealed subtypes of ADTKD-REN that are pathophysiologically, diagnostically, and clinically distinct.

A molecular mechanism explaining albuminuria in kidney disease.

Mammalian kidneys constantly filter large amounts of liquid, with almost complete retention of albumin and other macromolecules in the plasma. Breakdown of the three-layered renal filtration barrier results in loss of albumin into urine (albuminuria) across the wall of small renal capillaries, and is a leading cause of chronic kidney disease. However, exactly how the renal filter works and why its permeability is altered in kidney diseases is poorly understood. Here we show that the permeability of the renal filter is modulated through compression of the capillary wall. We collect morphometric data prior to and after onset of albuminuria in a mouse model equivalent to a human genetic disease affecting the renal filtration barrier. Combining quantitative analyses with mathematical modelling, we demonstrate that morphological alterations of the glomerular filtration barrier lead to reduced compressive forces that counteract filtration pressure, thereby resulting in capillary dilatation, and ultimately albuminuria. Our results reveal distinct functions of the different layers of the filtration barrier and expand the molecular understanding of defective renal filtration in chronic kidney disease.

EPG5 c.1007A > G mutation in a sibling pair with rapidly progressing Vici syndrome.

We report on a sibling pair with the EPG5 c.1007A > G mutation who developed a severe form of Vici syndrome and died in infancy. The c.1007A > G (p.Gln336Arg) mutation, affecting the penultimate nucleotide and the splicing of exon 2 is the most common mutation of EPG5 and is typically associated with a less devastating prognosis: cardiomyopathy and cataract are less frequent consequences and the median survival time is 78 months compared to an overall median survival of 42 months. The less severe course related to c.1007A > G was formerly explained by the preserved canonical splicing in 25% of the transcripts. In contrast, we found the messenger RNA encoded by the c.1007A > G allele to be absent, explaining the severe course of the disease. This family provides another example of phenotypic variability related to a differential splicing.

[Trisomy 9p and clinical heterogeneity: case report of an unusual presentation]. / 9p triszómia és a klinikai sokszínuség: egy váratlan megjelenésu eset ismertetése.

Whole or partial trisomy of the short arm of chromosome 9 (9p) is considered to be one of the more frequent chromosome abnormalities compatible with life. The duplication may affect various organs, however the most common symptoms are certain specific facial dysmorphisms and abnormalities of the fingers, toes and nails. A one month old boy presented with failure to thrive, jaundice, ventricular septal defect (VSD) and dysmorphic face. He displayed symptoms of heart failure. The cardiologic examination revealed a significant VSD, hypoplasia of the aortic arch, pulmonary hypertension, decompensated circulatory failure and moderate left ventricle dysfunction. Routine cytogenetic analysis revealed a supernumerary marker chromosome. Fluorescence in situ hybridization (FISH) identified this as the short arm of chromosome 9. The child's karyotype was determined as 47,XY,+der(9)dup(9)(p10p24)dn. Due to his worsening condition and the high risk of the operation, it was decided to forego the procedure. After a short palliative care the child passed away. The child's clinical presentation and the uncharacteristic severity of his condition show that chromosome abnormalities involving duplicated genetic material are extremely heterogeneous. Thus treatment of each child should be individualized and may also involve difficult ethical considerations. Orv Hetil. 2018; 159(47): 1994-2000.