A Novel Mutation of ORNT1 Detected in a Hyperornithinemia-Hyperammonemia-Homocitrullinuria Syndrome Child by Clinical Whole-Exome Sequencing.

Hyperornithinemia-hyperammonemia-homocitrullinuria (HHH) syndrome, an inborn error of metabolism, is an inherited syndrome caused by loss-of-function mutations in the SLC25A15, resulting in ornithine translocase1 (ORNT1) deficiency. Disrupted ornithine transportation in an affected individual usually manifests with the accumulation of intermediate metabolites, leading to neurological impairment, hepatitis, and/or protein intolerance at various ages of onset. In this paper, we report a compound heterozygous mutation in SLC25A15 from a 2-year-old girl who presented with neurological alterations and hepatic failure. Before developing neurological sequelae, she had signs of globally delayed development. The accumulation of toxic metabolites may explain these neurological consequences. After biochemical confirmation of HHH, whole-exome sequencing (WES) was performed, which identified mutations at codons 21 and 179 of SLC25A15 that are predicted to result in the loss of function of ORNT1. Each of the mutations was found to be inherited from one of her parents. After therapy, her toxic metabolites decreased significantly. In conclusion, HHH syndrome frequently manifests with nonspecific symptoms and unapparent biochemical profiles, which may lead to delayed diagnosis. Correction of the accumulating metabolites is necessary to prevent irreversible neurological impairment. Furthermore, performing a WES provides a shortcut for accurate diagnosis.

Whole-exome sequencing of vulvar squamous cell carcinomas reveals an impaired prognosis in patients with TP53 mutations and concurrent CCND1 gains.

Very little information is available on the mutational landscape of vulvar squamous cell carcinoma (VSCC), a disease that mainly affects older women. Studies focusing on the mutational patterns of the currently recognized etiopathogenic types of this tumor [human papillomavirus (HPV)-associated (HPV-A), HPV-independent (HPV-I) with TP53 mutation (HPV-I/TP53mut), and HPV-I with wild-type TP53 (HPV-I/TP53wt]) are particularly rare, and there is almost no information on the prognostic implications of these abnormalities. Whole-exome DNA sequencing of 60 VSCC and matched normal tissues from each patient was performed. HPV detection, immunohistochemistry (IHC) for p16, p53, and mismatch repair proteins were also performed. Ten tumors (16.7%) were classified as HPV-A, 37 (61.7%) as HPV-I/TP53mut, and 13 (21.6%) as HPV-I/TP53wt. TP53 was the most frequently mutated gene (66.7%), followed by FAT1 (28.3%), CDKN2A (25.0%), RNF213 (23.3%), NFE2L2 (20%) and PIK3CA (20%). All the 60 tumors (100%) were DNA mismatch repair proficient. Seventeen tumors (28.3%) showed CCND1 gain. Bivariate analysis, adjusted for FIGO stage, revealed that TP53 mutation, CCND1 gain, and the combination of the two alterations were strongly associated with impaired recurrence-free survival (hazard ratio=4.4, p<0.001) and disease-specific survival (hazard ratio=6.1, p=0.002). Similar results were obtained when p53 IHC status was used instead of TP53 status and when considering only HPV-I VSCC. However, in the latter category, p53 IHC maintained its prognostic impact only in combination with CCND1 gains. All tumors carried at least one potentially actionable genomic alteration. In conclusion, VSCCs with CCND1 gain represent a prognostically adverse category among HPV-I/TP53mut tumors. All patients with VSCCs are potential candidates for targeted therapy.

Molecular analysis of 31 cases with fetal skeletal dysplasia.

OBJECTIVES: The aim of this study was to describe the prenatal ultrasound findings of fetuses with skeletal dysplasia and to evaluate the genetic variations by molecular genetic analysis. METHODS: Between August 1, 2018 and March 1, 2023, we conducted a retrospective case series at a tertiary referral center involving patients with fetal skeletal abnormalities. For cases referred for a possible diagnosis of fetal skeletal dysplasia, an ultrasound database and prenatal genetic counseling records were first searched. Terminated cases diagnosed with skeletal dysplasia by pathologic and radiologic findings and cases with skeletal dysplasia proven by postnatal clinical findings were included in the study. RESULTS: Between 2018 and 2023, a total of 64 cases were diagnosed as skeletal dysplasia based on radiologic findings, pathologic findings, and clinical features. The median week of the first ultrasound performed on patients is 19 0/7 weeks, while the median week of the ultrasound in which skeletal dysplasia is suspected is 21 3/7 weeks. Although micromelia was evaluated as a common feature in all cases, the most common concomitant anomaly was thoracic hypoplasia. Exome sequencing analysis was achieved in 31 (48 %) of cases. In 31 cases, in total of 35 pathogenic single gene mutations and 5 VUS (variants of uncertain significance) variants composing of 23 autosomal dominant, 10 autosomal recessive and 2 X linked recessive mutations were determined. CONCLUSIONS: Prenatal ultrasound findings can lead us to specific diagnoses, and with the appropriate molecular analysis method, a definitive diagnosis can be made without wasting time and money.

Many Faces of Diencephalic-Mesencephalic Junction Dysplasia Syndrome with GSX2 and PCDH12 Variants.

Introduction: Diencephalic-mesencephalic junction dysplasia syndrome is a rare neurogenetic disorder reported to be caused by variants in several genes. Phenotypic presentation is characterized by clinical findings including developmental delay, hypotonia, spasticity, and dyskinetic movements in combination with distinctive imaging features on brain magnetic resonance imaging (MRI). Methods: Whole exome sequencing was conducted to unveil the molecular etiology of patients presenting with neurological manifestations from two unrelated families. Results: To the best of our knowledge, here we report the third family affected with diencephalic-mesencephalic junction dysplasia caused by a novel variant in GSX2 and two siblings with a PCDH12 variant exhibiting a less severe phenotype. The siblings with a PCDH12 variant were positioned at the milder end of the phenotypic spectrum. Although both exhibited a clinical phenotype resembling cerebral palsy, one showed partial fusion of the hypothalamus and mesencephalon, whereas MRI was unremarkable in the other. Biallelic GSX2 variants have been implicated in basal ganglia agenesis, and similarly, our patients had basal ganglia hypoplasia along with hypothalamic-mesencephalic fusion. Conclusion: Identifying variants associated with the syndrome in different genes will contribute to genotype-phenotype correlation.

Compound heterozygous CFTR variants (Q1352H and 5T; TG13) in a Chinese patient with cystic fibrosis.

Cystic fibrosis (CF) is an autosomal recessive inherited disease caused by variants of cystic fibrosis transmembrane conductance regulation (CFTR) gene. This report presents a case of a Chinese boy diagnosed with CF, attributed to the presence of two specific CFTR gene variations: 4056G > C (NM_000492.4) (p.Gln1352His, legacy: Q1352H) and c.1210-34TG[13]T[5] (NM_000492.4)(legacy: 5T; TG13). A ten-year-old boy was admitted to the hospital due to recurrent pneumonia, cough, and intermittent fever for seven years. Lung auscultation revealed rales, and a lung CT scan indicated parenchymal transformation with infection in both lungs. Whole Exome Sequencing (WES) identified two CFTR gene variants, Q1352H and 5T; TG13, which were significantly associated with clinical phenotype. Following a two-year course of azithromycin combined with inhalation therapy with budesonide, the patient experienced no further episodes of respiratory infections. Moreover, significant improvements were observed in pulmonary function, pulmonary infection, and bronchiectasis. The occurrence of combined variations, Q1352H and 5T; TG13, in the CFTR gene is rare and specific to Chinese populations. WES proves to be a valuable diagnostic tool for detecting CFTR gene variants.

Case report: Genetic diagnoses in a pediatric patient with retinoblastoma and comorbid global developmental delay: three distinct entities diagnosed by whole exome sequencing in a single patient.

Background: The objective of this study was to explore the genetic etiology and propose a genetic diagnosis and counseling strategy for children with retinoblastoma (RB) and global developmental delay (GDD). Case presentation: We report on a 2 years and 4 months old boy with binocular retinoblastoma and global developmental delay (included intellectual disability, language development delay, motor development delay, etc.). Genomic DNA was extracted from peripheral blood mononuclear cells isolated from the proband and his parents. Whole exome sequencing (WES) was carried out for the proband and his parents to identify genetic etiology, which was subsequently verified by quantitative polymerase chain reaction (qPCR).The WES revealed a gross heterozygous deletion in the RB transcriptional corepressor 1 (RB1, OMIM:614041) gene, including exon 7-8, in the affected proband but not in his parents. Additionally, two pathogenic copy number variations (CNVs) were identified: a duplication at 7q11.23 and a microdeletion at 16p11.2-p12.2, respectively. Furthermore, the genomic qPCR analysis demonstrated a 50% reduction in the copy numbers of exon 7 and exon 8 in the RB1 gene of the proband, as compared to those detected in his parents. Simultaneous variants in the RB1 gene and two pathogenic CNVs can precisely explain the genetic etiology of the proband. Conclusion: The present study firstly reports a novel gross deletion variant of the RB1 gene coexisting with two pathogenic CNVs in a pediatric patient with retinoblastoma and comorbid global developmental delay in China. Additionally, our findings strongly support the use of WES in pediatric patients with RB comorbid GDD, and WES is recommended as the first-tier test.

Whole-exome sequencing and copy number alterations analysis in a case of expansive florid cemento-osseous dysplasia.

Whole-exome sequencing (WES) analysis of an expansive case florid cemento-osseus dysplasia were reported for the first time. Also, the new potential candidate genes were reported to expand our knowledge about their molecular pathogenesis. Abstract: We report a case of expansive florid cemento-osseus dysplasia in a 32-year-old female patient who presented an expansive tumoral lesion in the anterior mandible. As florid cemento-osseus dysplasia have only been molecularly investigated using targeted-sequencing, fragments of the lesion were collected and subjected to molecular investigation using WES to assess somatic mutations as well as copy number alterations. No gains and losses of chromosomal arms or segments longer than 1 Mb were detected. Our findings revealed a pathogenic stopgain variant at the KIF5C gene, a stoploss variant at MAPK10, and missense SNV at COL6A2 at DCDC1, suggesting potential candidate genes associated with florid cemento-osseus dysplasia.

Comprehensive molecular characterization of collecting duct carcinoma for therapeutic vulnerability.

Collecting duct carcinoma (CDC) is an aggressive rare subtype of kidney cancer with unmet clinical needs. Little is known about its underlying molecular alterations and etiology, primarily due to its rarity, and lack of preclinical models. This study aims to comprehensively characterize molecular alterations in CDC and identify its therapeutic vulnerabilities. Through whole-exome and transcriptome sequencing, we identified KRAS hotspot mutations (G12A/D/V) in 3/13 (23%) of the patients, in addition to known TP53, NF2 mutations. 3/13 (23%) patients carried a mutational signature (SBS22) caused by aristolochic acid (AA) exposures, known to be more prevalent in Asia, highlighting a geologically specific disease etiology. We further discovered that cell cycle-related pathways were the most predominantly dysregulated pathways. Our drug screening with our newly established CDC preclinical models identified a CDK9 inhibitor LDC000067 that specifically inhibited CDC tumor growth and prolonged survival. Our study not only improved our understanding of oncogenic molecular alterations of Asian CDC, but also identified cell-cycle machinery as a therapeutic vulnerability, laying the foundation for clinical trials to treat patients with such aggressive cancer.

Genomic landscape of hepatocellular carcinoma in Egyptian patients by whole exome sequencing.

BACKGROUND: Hepatocellular carcinoma (HCC) is the most common primary liver cancer. Chronic hepatitis and liver cirrhosis lead to accumulation of genetic alterations driving HCC pathogenesis. This study is designed to explore genomic landscape of HCC in Egyptian patients by whole exome sequencing. METHODS: Whole exome sequencing using Ion Torrent was done on 13 HCC patients, who underwent surgical intervention (7 patients underwent living donor liver transplantation (LDLT) and 6 patients had surgical resection}. RESULTS: Mutational signature was mostly S1, S5, S6, and S12 in HCC. Analysis of highly mutated genes in both HCC and Non-HCC revealed the presence of highly mutated genes in HCC (AHNAK2, MUC6, MUC16, TTN, ZNF17, FLG, MUC12, OBSCN, PDE4DIP, MUC5b, and HYDIN). Among the 26 significantly mutated HCC genes-identified across 10 genome sequencing studies-in addition to TCGA, APOB and RP1L1 showed the highest number of mutations in both HCC and Non-HCC tissues. Tier 1, Tier 2 variants in TCGA SMGs in HCC and Non-HCC (TP53, PIK3CA, CDKN2A, and BAP1). Cancer Genome Landscape analysis revealed Tier 1 and Tier 2 variants in HCC (MSH2) and in Non-HCC (KMT2D and ATM). For KEGG analysis, the significantly annotated clusters in HCC were Notch signaling, Wnt signaling, PI3K-AKT pathway, Hippo signaling, Apelin signaling, Hedgehog (Hh) signaling, and MAPK signaling, in addition to ECM-receptor interaction, focal adhesion, and calcium signaling. Tier 1 and Tier 2 variants KIT, KMT2D, NOTCH1, KMT2C, PIK3CA, KIT, SMARCA4, ATM, PTEN, MSH2, and PTCH1 were low frequency variants in both HCC and Non-HCC. CONCLUSION: Our results are in accordance with previous studies in HCC regarding highly mutated genes, TCGA and specifically enriched pathways in HCC. Analysis for clinical interpretation of variants revealed the presence of Tier 1 and Tier 2 variants that represent potential clinically actionable targets. The use of sequencing techniques to detect structural variants and novel techniques as single cell sequencing together with multiomics transcriptomics, metagenomics will integrate the molecular pathogenesis of HCC in Egyptian patients.

Genotype is associated with left ventricular reverse remodelling and early events in recent-onset dilated cardiomyopathy.

AIMS: Recent-onset dilated cardiomyopathy (RODCM) is characterized by heterogeneous aetiology and diverse clinical outcomes, with scarce data on genotype-phenotype correlates. Our aim was to correlate individual RODCM genotypes with left ventricular reverse remodelling (LVRR) and clinical outcomes. METHODS AND RESULTS: In this prospective study, a total of 386 Czech RODCM patients with symptom duration ≤6 months underwent genetic counselling and whole-exome sequencing (WES). The presence of pathogenic (class 5) or likely pathogenic (class 4) variants in a set of 72 cardiomyopathy-related genes was correlated with the occurrence of all-cause death, heart transplantation, or implantation of a ventricular assist device (primary outcome) and/or ventricular arrhythmia event (secondary outcome). LVRR was defined as an improvement of left ventricular ejection fraction to >50% or ≥10% absolute increase, with a left ventricular end-diastolic diameter ≤33 mm/m2 or ≥10% relative decrease. Median follow-up was 41 months. RODCM was familial in 98 (25%) individuals. Class 4-5 variants of interest (VOIs) were identified in 125 (32%) cases, with 69 (18%) having a single titin-truncating variant (TTNtv) and 56 (14%) having non-titin (non-TTN) VOIs. The presence of class 4-5 non-TTN VOIs, but not of TTNtv, heralded a lower probability of 12-month LVRR and proved to be an independent baseline predictor both of the primary and the secondary outcome. The negative result of genetic testing was a strong protective baseline variable against occurrence of life-threatening ventricular arrhythmias. Detection of class 4-5 VOIs in genes coding nuclear envelope proteins was another independent predictor of both study outcomes at baseline and also of life-threatening ventricular arrhythmias after 12 months. Class 4-5 VOIs of genes coding cytoskeleton were associated with an increased risk of life-threatening ventricular arrhythmias after baseline assessment. A positive family history of dilated cardiomyopathy alone only related to a lower probability of LVRR at 12 months and at the final follow-up. CONCLUSIONS: RODCM patients harbouring class 4-5 non-TTN VOIs are at higher risk of progressive heart failure and life-threatening ventricular arrhythmias. Genotyping may improve their early risk stratification at baseline assessment.

Successful intracytoplasmic sperm injection in a macrozoospermia case with novel compound heterozygous aurora kinase C (AURKC) mutations.

PURPOSE: To explore the application possibility of macrocephalic sperm from a patient with 100% macrocephalic sperm and AURKC gene variations. METHODS: We diagnosed a case of macrozoospermia with 100% macrocephalic sperm and 39.5% multi-tailed spermatozoa by morphological analysis. Whole-exome sequencing (WES) was used for the patient and his wife. Sanger sequencing technique was used to verify the AURKC mutations in the patient's parents and his offspring. Sperm's ploidy was tested by flow cytometry. The couple asked for intra-couple ART therapy. RESULTS: The patient presented novel compound heterozygous AURKC mutations (c.434C > T, c.497A > T) by WES. Sanger sequencing validation showed that variant of c.434C > T was observed in his father and c.497A > T was observed in his mother. Flow cytometry revealed that there existed a certain proportion of haploid sperm. Macrocephalic spermatozoa whose heads were smaller than the diameter of injection needle were selected for microinjection. A singleton pregnancy was achieved after embryo transfer. Prenatal diagnosis revealed that the fetus had normal chromosomal karyotype. Sanger sequencing technique showed that the fetus carried a c.434C > T mutation in one AURKC allele. A 3730 g healthy male fetus was delivered at term. CONCLUSION: Our study reported a successful live birth from a patient with definite AURKC gene variants and may provide insights for such patients to choose donor sperm or their own sperm.

Prognostic mutations identified by whole-exome sequencing and validation of the Molecular International Prognostic Scoring System in myelodysplastic syndromes after allogeneic haematopoietic stem cell transplantation.

In this study, we used the whole-exome sequencing (WES) approach to obtain genomic profiles from 92 marrow samples of myelodysplastic syndrome (MDS) patients before haematopoietic stem cell transplantation. We identified 129 mutations in 45 driver genes. Fifty-five patients (59.8%) carried at least 1 driver mutation. The splicing factor U2AF1 was the most frequently mutated in the cohort (21 cases, 23%), followed by BCOR (9 cases, 10%), ASXL1 (8 cases, 9%), TET2 (6 cases, 7%), NPM1 (5 cases, 5%), RUNX1 (5 cases, 5%), and SETBP1 (5 cases, 5%). WES also identified 49 possible oncogenic variants in six genes (PIEZO1, LOXHD1, MYH13, DNAH5, DPH1, and USH2A) that were associated with overall survival (OS) or relapse-free survival (RFS) in MDS after transplantation. Multivariate analysis showed mutations in DNAH5 and USH2A to be independent risk factors for OS. Mutations in DNAH5 and LOXHD1 were risk factors for worse RFS. The Molecular International Prognostic Scoring System retained its independent prognostic significance for RFS after multivariate analysis.

Whole paternal uniparental disomy of chromosome 4 with a novel homozygous IDUA splicing variant, c.159-9T>A, in a Chinese patient with mucopolysaccharidosis type I.

BACKGROUND: Mucopolysaccharidosis type I (MPS-I) is a rare autosomal recessive genetic lysosomal storage disorder that is caused by pathogenic variants of the α-L-iduronidase (IDUA) gene. This study aimed to identify the genetic causes of MPS-I in a Chinese patient and construct a minigene of IDUA to analyze its variants upon splicing. METHODS: Whole-exome sequencing (WES) and Sanger sequencing were used to confirm the potential causative variants. Single-nucleotide polymorphism (SNP) array was subsequently performed to confirm uniparental disomy (UPD). Minigene assay was performed to analyze the effect on splicing of mRNA. We meanwhile explored the conservative analysis and protein homology simulation. RESULTS: A novel homozygous splicing mutation of IDUA, c.159-9T>A, was identified in an individual presenting with overlapping features of MPS-I. Interestingly, only the father and sisters, but not the mother, carried the variant in a heterozygous state. WES and SNP array analyses validated paternal UPD on chromosome 4. Minigene splicing revealed two aberrant splicing events: exon 2 skipping and intron 1 retention. Moreover, the specific structure of the mutant protein obviously changed according to the results of the homologous model. CONCLUSIONS: This study describes a rare autosomal recessive disorder with paternal UPD of chromosome 4 leading to the homozygosity of the IDUA splicing variant in patients with MPS-I for the first time. This study expands the variant spectrum of IDUA and provides insights into the splicing system, facilitating its enhanced diagnosis and treatment.

Somatic mutational landscape across Indian breast cancer cases by whole exome sequencing.

Breast cancer (BC) has emerged as the most common malignancy among females. The genomic profile of BC is diverse in nature and complex due to heterogeneity among various geographically different ethnic groups. The primary objective of this study was to carry out a comprehensive mutational analysis of Indian BC cases by performing whole exome sequencing. The cohort included patients with a median age of 48 years. TTN, TP53, MUC16, SYNE1, and OBSCN were the frequently altered genes found in our cohort. The PIK3CA and KLC3 genes are driver genes implicated in various cellular functions and cargo transportation through microtubules, respectively. Except for CCDC168 and PIK3CA, several gene pairings were found to be significantly linked with co-occurrence. Irrespective of their hormonal receptor status, RTK/RAS was observed with frequently altered signaling pathways. Further analysis of the mutational signature revealed that SBS13, SBS6, and SBS29 were mainly observed in our cohort. This study supplements the discovery of diagnostic biomarkers and provides new therapeutic options for the improved management of BC.

Gene-based association analysis of a large patient cohort provides insights into genetics of atypical femur fractures.

BACKGROUND: Several small genetic association studies have been conducted for atypical femur fracture (AFF) without replication of results. We assessed previously implicated and novel genes associated with AFFs in a larger set of unrelated AFF cases using whole exome sequencing (WES). METHODS: We performed gene-based association analysis on 139 European AFF cases and 196 controls matched for bisphosphonate use. We tested all rare, protein-altering variants using both candidate gene and hypothesis-free approaches. In the latter, genes suggestively associated with AFFs (uncorrected P-values <0.01) were investigated in a Swedish whole-genome sequencing replication study and assessed in 46 non-European cases. RESULTS: In the candidate gene analysis, PLOD2 showed a suggestive signal. The hypothesis-free approach revealed 10 tentative associations, with XRN2, SORD, and PLOD2 being the most likely candidates for AFF. XRN2 and PLOD2 showed consistent direction of effect estimates in the replication analysis, albeit not statistically significant. Three SNPs associated with SORD expression according to the GTEx portal, were in linkage disequilibrium (R2 ≥ 0.2) with a SNP previously reported in a genome-wide association study of AFF. The prevalence of carriers of variants for both PLOD2 and SORD was higher in Asian versus European cases. CONCLUSIONS: While we did not identify genes enriched for damaging variants, we found suggestive evidence of a role for XRN2, PLOD2 and SORD, which requires further investigation. Our findings indicate that genetic factors responsible for AFFs are not widely shared among AFF cases. The study provides a stepping-stone for future larger genetic studies of AFF.

We investigated the genetic factors contributing to atypical femur fractures (AFF), which are rare and unusual fractures in the thigh bone These fractures are related to the use of bisphosphonates, which are prescribed to prevent fractures caused by osteoporosis. Previous studies suggested potential genetic links, but their findings were not confirmed in larger groups. To address this, we analyzed genetic data from 139 European individuals with AFF and 196 individuals without AFF, all of whom used bisphosphonates, using a genetic technique called whole exome sequencing (WES). Our results suggested three genes­XRN2, SORD, and PLOD2­might be linked to AFF, although the evidence was not conclusive. Importantly, our findings suggest that AFF may be caused by different genes in different individuals. A much larger sample size is now needed to fully understand the genetic architecture of AFF. These findings may guide future research into the genetic causes of AFF.

Novel mutation patterns in children with steroid-resistant nephrotic syndrome.

Background: Idiopathic nephrotic syndrome (NS) in children poses treatment challenges, with a subset developing steroid-resistant nephrotic syndrome (SRNS). Genetic factors play a role, yet data on paediatric SRNS genetics in India are scarce. We conducted a prospective study using whole-exome sequencing to explore genetic variants and their clinical correlations. Methods: A single-centre prospective study (October 2018-April 2023) enrolled children with SRNS, undergoing renal biopsy and genetic testing per institutional protocol. Clinical, histological, and genetic data were recorded. DNA isolation and next-generation sequencing were conducted for genetic analysis. Data collection included demographics, clinical parameters, and kidney biopsy findings. Syndromic features were evaluated, with second-line immunosuppressive therapy administered. Patient and renal outcomes are presented for patients with and without genetic variants. Results: A total of 680 paediatric NS patients were analysed, with 121 (17.8%) having SRNS and 96 consent to genetic analysis. 69 (71.9%) had early SRNS, 27 (28.1%) late. Among participants, 62 (64.58%) had reportable genetic variants. The most common were in COL4A genes, with 20 (31.7%) positive. Renal biopsy showed focal segmental glomerulosclerosis in 31/42 (74%) with variants, 16/28 (57.1%) without variants. Second-line immunosuppressions varied, with CNIs the most common. Outcomes varied, with partial or complete remission achieved in some while others progressed to ESRD. Conclusion: The study underscores the importance of genetic analysis in paediatric SRNS, revealing variants in 65.7% of cases. COL4A variants were predominant. Variants correlated with varied renal outcomes, highlighting potential prognostic implications. These findings emphasize the value of personalized approaches and further research in managing paediatric SRNS.

[Kidney involvement in rare hereditary diseases].

Various rare inherited disorders can be associated with kidney involvement, including glomerulopathies, tubulopathies, multiple cysts, congenital anomalies of the kidneys and urinary tract, urolithiasis, malignant and benign tumors. Genetic nephropathy should be always considered in children, adolescents and young patients with the kidneys or urinary tract disorders and/or patients with positive family anamnesis. Extrarenal manifestations can be a valuable clue for diagnosis of certain hereditary diseases, e.g. neurosensory deafness in Alport syndrome or photofobia in nephropathic cystinosis. Diagnosis of monogenic inherited diseases should be verified by genetic testing. Specific drugs are available for treatment of certain hereditary diseases involving kidney, e.g. Fabry disease, cystinosis, primary hyperoxaluria I type and atypical hemolytic uremic syndrome.

Whole exome sequencing reveals a dual diagnosis of BCAP31-related syndrome and glutaric aciduria III.

Background: Biochemical testing is a common first-tier approach in the setting of genetic evaluation of patients with unexplained developmental delay. However, results can be unclear, and a plan for second-tier analysis must be determined based on the patient's biochemical results and clinical presentation - in many cases, triggering a diagnostic odyssey. Case presentation: A male patient from the United States presenting with unexplained developmental delay, microcephaly, hypotonia, and feeding difficulties was referred for clinical genetic evaluation at age 8 months. Biochemical testing revealed an isolated marked elevation of glutaric acid on urine organic acid profile, without elevations of related metabolites. Further testing included GCDH sequencing, a neurometabolic gene panel, chromosomal microarray, Prader Willi/Angelman testing, and lysosomal disease enzyme panel, all of which were non-diagnostic. The patient had persistent developmental delay and hypotonia, dystonia, sensorineural hearing loss, and abnormal brain myelination on magnetic resonance imaging. Whole exome sequencing (WES) was performed and revealed a dual diagnosis of glutaric aciduria III (GA III) and BCAP31-related disorder, an X-linked intellectual disability syndrome, caused by a novel pathogenic variant. Conclusions: GA III has historically been considered clinically benign, with few reported cases. This patient's presenting symptoms were similar to those commonly seen in GA I and GA II, however the biochemical abnormalities were not consistent with these disorders, prompting additional molecular and biochemical testing. Ultimately, WES confirmed a diagnosis of BCAP31-related syndrome, a rare neurological disorder, which explained the patient's presenting symptoms. WES also identified a secondary diagnosis of GA III. We present a patient with two rare genetic conditions, highlighting the importance of deep phenotyping and the utility of WES in the setting of a patient with dual genetic diagnoses.

Whole-exome and whole-genome sequencing of 1064 individuals with type 1 diabetes reveals novel genes for diabetic kidney disease.

AIMS/HYPOTHESIS: Diabetic kidney disease (DKD) is a severe diabetic complication that affects one third of individuals with type 1 diabetes. Although several genes and common variants have been shown to be associated with DKD, much of the predicted inheritance remains unexplained. Here, we performed next-generation sequencing to assess whether low-frequency variants, extending to a minor allele frequency (MAF) ≤10% (single or aggregated) contribute to the missing heritability in DKD. METHODS: We performed whole-exome sequencing (WES) of 498 individuals and whole-genome sequencing (WGS) of 599 individuals with type 1 diabetes. After quality control, next-generation sequencing data were available for a total of 1064 individuals, of whom 541 had developed either severe albuminuria or end-stage kidney disease, and 523 had retained normal albumin excretion despite a long duration of type 1 diabetes. Single-variant and gene-aggregate tests for protein-altering variants (PAV) and protein-truncating variants (PTV) were performed separately for WES and WGS data and combined in a meta-analysis. We also performed genome-wide aggregate analyses on genomic windows (sliding window), promoters and enhancers using the WGS dataset. RESULTS: In the single-variant meta-analysis, no variant reached genome-wide significance, but a suggestively associated common THAP7 rs369250 variant (p=1.50 × 10-5, MAF=49%) was replicated in the FinnGen general population genome-wide association study (GWAS) data for chronic kidney disease and DKD phenotypes. The gene-aggregate meta-analysis provided suggestive evidence (p<4.0 × 10-4) at four genes for DKD, of which NAT16 (MAFPAV≤10%) and LTA (also known as TNFß, MAFPAV≤5%) are replicated in the FinnGen general population GWAS data. The LTA rs2229092 C allele was associated with significantly lower TNFR1, TNFR2 and TNFR3 serum levels in a subset of FinnDiane participants. Of the intergenic regions suggestively associated with DKD, the enhancer on chromosome 18q12.3 (p=3.94 × 10-5, MAFvariants≤5%) showed interaction with the METTL4 gene; the lead variant was replicated, and predicted to alter binding of the MafB transcription factor. CONCLUSIONS/INTERPRETATION: Our sequencing-based meta-analysis revealed multiple genes, variants and regulatory regions that were suggestively associated with DKD. However, as no variant or gene reached genome-wide significance, further studies are needed to validate the findings.