Search Results (1,201)

Background/Objectives: Glycogen storage disease type II, also known as Pompe disease (PD), is a rare autosomal recessive genetic disorder triggered by a deficiency in lysosomal acid α-glucosidase (GAA). Recently, we discovered two deleterious missense variants of the GAA gene, c.1799G>A (p.Arg600His) (a pathogenic mutation) and c.55G>A (p.Val19Met), in a domestic short-haired cat with PD. This study aimed to design genotyping assays for these two variants and ascertain their allele frequencies in Japanese cat populations. Methods: We developed fluorescent probe-based real-time polymerase chain reaction assays to genotype the c.1799G>A and c.55G>A variants. A total of 738 cats, comprising 99 purebred cats from 20 breeds and 540 mixed-breed cats, were screened using these assays. Results: Genotyping assays clearly differentiated all known genotypes of the two variants. None of the 738 cats tested carried the c.1799G>A variant. However, we identified cats with c.55G/A and c.55A/A genotypes in the purebred (A allele frequency: 0.081) and mixed-breed cats (0.473). A significant difference (p < 0.001) was observed in the A allele frequency between the two groups. Conclusions: The c.1799G>A mutation appears rare in cat populations, suggesting it may be confined to specific pedigree Japanese mixed-breed cats. The c.55G>A variant was detected in purebred and mixed-breed cats, suggesting that it may not be directly linked to feline PD. However, additional studies are required to elucidate the precise relationship between this variant and cardiac function. Genotyping assays will serve as valuable tools for diagnosing and genotyping feline PD. Full article

Nephrotic syndrome (NS) is characterized by proteinuria, hypoalbuminemia, edema, and hyperlipidemia. Apart from the traditional causes of NS, such as minimal change disease, focal segmental glomerulosclerosis, diabetes, infections, malignancies, autoimmune conditions, and nephrotoxic agents, there are also rare causes of NS, whose knowledge is of the utmost importance. The aim of this article was to highlight the less well-known causes that have a significant impact on diagnosis and treatment. Genetic syndromes such as Schimke immuno-osseous dysplasia, familial lecithin-cholesterol acyltransferase deficiency with two clinical variants (fish-eye Disease and the p.Leu364Pro mutation), lead to NS through mechanisms involving podocyte and lipid metabolism dysfunction. Congenital disorders of glycosylation and Nail–Patella Syndrome emphasize the role of deranged protein processing and transcriptional regulation in glomerular injury. The link of NS with type 1 diabetes, though rare, suggests an etiology on the basis of common HLA loci and immune dysregulation. Histopathological analysis, particularly electron microscopy, shows mainly podocyte damage, mesangial sclerosis, and alteration of the basement membrane, which aids in differentiating rare forms. Prompt recognition of these novel etiologies by genetic analysis, renal biopsy, and an interdisciplinary panel is essential to avoid delays in diagnosis and tailored treatment. Full article

Congenital cataracts (CCs) are a leading cause of preventable childhood blindness, with genetic factors playing a crucial role in their etiology. Nance–Horan syndrome (NHS) is a rare X-linked dominant disorder associated with CCs but is often underdiagnosed due to variable expressivity, particularly in female carriers. Objective: This study aimed to explore the genetic landscape of CCs in a Swiss cohort, focusing on two novel NHS and one novel GJA8 variants and their phenotypic presentation. Methods: Whole-exome sequencing (WES) was conducted on 20 unrelated Swiss families diagnosed with CCs. Variants were analyzed for pathogenicity using genetic databases, and segregation analysis was performed. Clinical data, including cataract phenotype and associated systemic anomalies, were assessed to establish genotype–phenotype correlations. Results: Potentially pathogenic DNA sequence variants were identified in 10 families, including three novel variants, one in GJA8 (c.584T>C) and two NHS variants (c.250_252insA and c.484del). Additional previously reported variants were detected in CRYBA1, CRYGC, CRYAA, MIP, EPHA2, and MAF, reflecting genetic heterogeneity in the cohort. Notably, NHS variants displayed significant phenotypic variability, suggesting dose-dependent effects and X-chromosome inactivation in female carriers. Conclusions: NHS remains underdiagnosed due to its variable expressivity and the late manifestation of systemic features, often leading to misclassification as isolated CC. This study highlights the importance of genetic testing in unexplained CC cases to improve early detection of syndromic forms. The identification of novel NHS and GJA8 variants provides new insights into the genetic complexity of CCs, emphasizing the need for further research on genotype–phenotype correlations. Full article

Background and Clinical Significance: Multiple Endocrine Neoplasia type 1 (MEN1) is a rare autosomal dominant disorder caused by mutations in the MEN1 gene. Although primarily characterized by endocrine tumors, renal manifestations remain underreported. Case Presentation: We report a three-generation family carrying a pathogenic MEN1 mutation (c.1351-3_1359del) with a co-occurring Claudin 16 (CLDN16) variant (c.324+13C>G). Genetic testing included MLPA and whole-exome sequencing (WES), with bioinformatics analysis validating variant pathogenicity. All three patients exhibited primary hyperparathyroidism, hypercalcemia, hypercalciuria, early nephrocalcinosis, and renal hypomagnesemia. The CLDN16 variant, previously considered benign, co-segregated with hypomagnesemia and renal involvement, suggesting a potential modifying role. Conclusions: These findings support the need for comprehensive genetic screening in MEN1 patients with atypical renal presentations. Concomitant genetic variations can alter the principal phenotype. Full article

Primary ciliary dyskinesia (PCD) is a rare, genetically heterogeneous disorder that impairs mucociliary clearance and leads to progressive lung disease. This study aimed to characterize lung function decline in a genetically homogeneous cohort of Puerto Rican patients with RSPH4A-associated PCD and to develop a clinical tool to predict lung function decline and support transplant referral decisions. We conducted a retrospective chart review of patients (n = 25) with a confirmed RSPH4A [c.921+3_6delAAGT] genetic variant, collecting longitudinal spirometry data and applying linear regressions to calculate each patient’s individual FEV₁ decline. The median FEV₁ at diagnosis was 55%, with a median annual decline of −0.75% predicted. Adults exhibited significantly lower lung function compared to pediatric patients, while no difference was seen between males and females. Based on this observed decline, we developed the Predicted Capacity Decline Index (PCDx), an index that estimates the age and time until a patient reaches the 30% FEV₁ threshold, the point at which lung transplant referral is typically considered. Our findings underscore the need for early intervention and suggest that genotype-specific tools like the PCDx may enhance clinical decision-making in managing progressive lung disease in PCD. Full article

Nephrogenic diabetes insipidus (NDI) is a rare hereditary disorder characterized by renal resistance to arginine vasopressin (AVP), resulting in the kidneys’ inability to concentrate urine. Approximately 90% of NDI cases follow an X-linked inheritance pattern and are associated with pathogenic variants in the AVPR2 gene, which encodes the vasopressin receptor type 2. The remaining 10% are attributed to mutations in the AQP2 gene, which encodes aquaporin-2, and may follow either autosomal dominant or recessive inheritance patterns. We present the case of a male infant, younger than nine months of age, who was clinically diagnosed with NDI at six months. The patient presented recurrent episodes of polydipsia, polyuria, dehydration, hypernatremia, and persistently low urine osmolality. Despite adjustments in pharmacologic treatment and strict monitoring of urinary output, the clinical response remained suboptimal. Given the lack of improvement and the radiological finding of an absent posterior pituitary (neurohypophysis), the possibility of coexistent central diabetes insipidus (CDI) was raised, prompting a therapeutic trial with desmopressin. Nevertheless, in the absence of clinical improvement, desmopressin was discontinued. The patient’s management was continued with hydrochlorothiazide, ibuprofen, and a high-calorie diet restricted in sodium and protein, resulting in progressive clinical stabilization. Whole-exome sequencing identified a novel homozygous missense variant in the AQP2 gene (c.398T > A; p.Val133Glu), classified as likely pathogenic according to the American College of Medical Genetics and Genomics (ACMG) criteria: PM2 (absent from population databases), PP2 (missense variant in a gene with a low rate of benign missense variation), and PP3 (multiple lines of computational evidence supporting a deleterious effect)]. NDI is typically diagnosed during early infancy due to the early onset of symptoms and the potential for severe complications if left untreated. In this case, although initial clinical suspicion included concomitant CDI, the timely initiation of supportive management and the subsequent incorporation of molecular diagnostics facilitated a definitive diagnosis. The identification of a previously unreported homozygous variant in AQP2 contributed to diagnostic confirmation and therapeutic decision-making. The diagnosis and comprehensive management of NDI within the context of polyuria-polydipsia syndrome necessitates a multidisciplinary approach, integrating clinical evaluation with advanced molecular diagnostics. The novel AQP2 c.398T > A (p.Val133Glu) variant described herein was associated with early and severe clinical manifestations, underscoring the importance of genetic testing in atypical or treatment-refractory presentations of diabetes insipidus. Full article

Familial dysbetalipoproteinemia (FD) is a prevalent and highly atherogenic hyperlipoproteinemia associated with the ε2/ε2 APOE genotype or rare APOE variants. The contributions of additional genetic and clinical factors to the FD phenotype remain unclear. We investigated these factors in both autosomal recessive and autosomal dominant forms of FD. Targeted (n = 4666) and exome (n = 194) sequencing were used to identify the ε2/ε2 APOE genotype or rare FD-causative APOE variants. Twenty-four lipid-related genes and forty variants included in a polygenic risk score for hypertriglyceridemia (HTG) were analyzed. FD was defined by the presence of FD variants and triglycerides (TG) ≥ 1.5 mmol/L (main study group). The comparison group consisted of patients with FD variants but TG < 1.5 mmol/L. Univariable and multivariable regression analyses were performed. A total of 71 unrelated subjects were identified (45.1% male, median age 50 years). FD was diagnosed in 52 patients, while 19 had FD variants only. Age (p = 0.019), elevated polygenic risk for HTG (p = 0.001), and the presence of metabolic syndrome components (p = 0.014) were independently associated with the FD phenotype. TG levels were significantly associated with polygenic burden (0.05 mmol/L per percentile), the presence of additional rare lipid-related variants (7.0 mmol/L), and glucose metabolism disorders (3.62 mmol/L), together explaining 30% of TG variance in cross-validated model. These results highlight the interplay of genetic and metabolic factors in FD development and support the integration of HTG genetic risk scores and metabolic control into personalized FD management. Full article

Inherited epidermolysis bullosa (EB) is a heterogeneous clinical entity that includes over 30 phenotypically and/or genotypically distinct inherited disorders, characterized by mechanical skin fragility and bullae formation. Junctional EB (JEB) is an autosomal recessive disease characterized by an intermediated cleavage level within the skin layers, commonly at the “lamina lucida”. Laryngo-onycho-cutaneous syndrome (LOC) is an extremely rare variant of JEB, characterized by granulation tissue formation in specific body sites (skin, larynx, and nails). Although most cases of JEB are caused by pathogenic variants occurring in the genes encoding for classical components of the lamina lucida, such as laminin 332 (LAMA3, LAMB3, LAMC2), integrin α6β4 (ITGA6, ITGB4), and collagen XVII (COL17A1), other variants have also been described. We report the case of a 4-month-old male infant who presented with recurrent bullous and erosive lesions from the first month of life. At the first dermatological evaluation, the patient was agitated and exhibited hoarse breathing, a clinical sign suggestive of laryngeal involvement. Multiple polygonal skin erosions were observed on the cheeks, along with similar isolated, roundish lesions on the scalp and legs. Notably, nail dystrophy and near-complete anonychia were evident on the left first and fifth toes. Due to the coexistence of skin erosions and nail dystrophy in such a young infant, a congenital bullous disorder was suspected, prompting molecular analysis of all potentially involved genes. In the patient’s DNA, clinical exome sequencing (CES) identified a pathogenic variant, apparently in homozygosity, in the exon 1 of the LAMA3 gene (18q11.2; NM_000227.6): c.47G > A;p.Trp16*. The presence of this variant was confirmed, in heterozygosity, in the genomic DNA of the patient’s mother, while it was absent in the father’s DNA. Subsequently, trio-based SNP array analysis was performed, revealing a paternally derived pathogenic microdeletion encompassing the LAMA3 locus (18q11.2). To our knowledge, this is the first reported case of JEB with a LOC-like phenotype caused by a maternally inherited monoallelic nonsense mutation in LAMA3, unmasked by an almost complete deletion of the paternal allele. The combined use of exome sequencing and SNP array is proving essential for elucidating autosomal recessive diseases with a discordant segregation. This is pivotal for providing accurate genetic counseling to parents regarding future pregnancies. Full article

Background: Autism spectrum disorder (ASD) is a heterogeneous group of neurodevelopmental disorders characterized by a complex, multifactorial etiology with a strong genetic contribution. Our study aimed to evaluate the link between the burden of rare genetic variants within a specific panel of ASD and intellectual disability-associated genes and phenotypic variability in a cohort of children with autism in Slovakia. Methods: Gene burden scores were calculated based on pathogenic, likely pathogenic, and uncertain significance rare DNA variants identified by whole-exome sequencing. We then assessed the effect of three different scoring methods on the variance across 15 psycho-behavioral parameters describing the phenotypic profiles of 117 ASD probands. Results: The burden score showed a significant multivariate effect on the combination of psycho-behavioral parameters. This score was associated with the social affect of ADOS-2, as well as with the socialization domain, and total adaptive behavior scores from the Vineland Adaptive Behavior Scales-3 (VABS). While a score based solely on count of pathogenic and likely pathogenic variants did not show a multivariate effect, incorporating variants of uncertain significance revealed a multivariate effect on two adaptive behavior parameters: daily living skills and total adaptive behavior score (VABS). Conclusions: Our findings partially explain the variability in phenotypic manifestation in our ASD patient cohort, highlighting the importance of considering the cumulative effect of rare genetic variants, including those of uncertain significance, in shaping the diverse clinical presentation of ASD. Full article

Background: Perceptual analysis has highlighted that the voice characteristics of patients with rare congenital genetic syndromes differ from those of normophonic subjects. In this paper, we describe the voice phenotype, also called the phonotype, of patients with Crisponi/cold-induced sweating syndrome type 1 (CS/CISS1). Methods: We conducted an observational study at the Department of Life Sciences and Public Health, Rome. Thirteen patients were included in this study (five males; mean age: 16 years; SD: 10.63 years; median age: 12 years; age range: 6–44 years), and five were adults (38%). We prospectively recorded and analyzed acoustical features of three corner vowels [a], [i], and [u]. For perceptual analysis, the GIRBAS (grade, instability, roughness, breathiness, asthenia, and strain) scale was utilized. Acoustic analysis was performed through BioVoice software. Results: We found that CS/CISS1 patients share a common phonotype characterized by articulation disorders and hyper-rhinophonia. Conclusions: This study contributes to delineating the voice of CS/CISS1 syndrome. The phonotype can represent one of the earliest indicators for detecting rare congenital conditions, enabling specialists to reduce diagnosis time and better define a spectrum of rare and ultra-rare diseases. Full article

Background: Congenital insensitivity to pain with anhidrosis (CIPA) is a rare genetic disorder, often leading to injuries and serious infections. In 2018, we established a multidisciplinary clinic (MDC) to provide structured, proactive care. We assessed the MDC’s impact on hospitalizations, surgeries, and infection rates. Methods: A retrospective study of genetically confirmed CIPA patients, treated from 2014 to 2024. Data from electronic medical records were compared between the pre-MDC (2014–2017) and post-MDC (2018–2024) periods. The core MDC team includes an infectious disease specialist, orthopedic surgeon, and nurses. The patients are stratified according to their carriage of resistant organisms and are managed using strict infection control measures. Follow-ups are scheduled routinely or as needed. Treatment is guided by clinical findings and culture results. Results: A total of 59 patients were included in the study. The baseline age did not differ significantly between the two periods. Hospitalization rates declined by 30.7% (from 57.7 to 40.0 per 1000 days), and clinic visits decreased by 42.9% (25.5 to 14.6). Overall surgical rates remained stable (2.8 to 2.7), with a 61.9% decrease in eye surgeries and a 130.5% increase in elective tooth extractions. Infection rates increased by 52% (from 6.6 to 10.1 per 1000 days). Conclusions: The implementation of the MDC bundle led to reduced hospitalizations, clinic visits, and eye surgeries, alongside the increased use of elective tooth extractions and culture testing. Closer monitoring and early infection management contributed to fewer severe complications. These findings support the value of structured, proactive multidisciplinary care in improving outcomes for children with CIPA. Full article

Alveolar capillary dysplasia with misalignment of pulmonary veins (ACDMPV) is a rare, often fatal congenital disorder characterized by severe neonatal respiratory distress and associated with complex multisystem malformations. In approximately 90% of cases, the condition is linked to deletions or mutations affecting the FOXF1 gene or its upstream enhancer region on chromosome 16q24.1. This review analyzes reported prenatal cases with 16q24.1 deletion involving FOXF1, aiming to identify recurrent sonographic features and elucidate the underlying genomic and epigenetic mechanisms. We reviewed prenatal cases reported in the literature involving deletions of the 16q24.1 region, including the FOXF1 gene. Here, we expand the case series by reporting a fetus with increased nuchal translucency measuring 8 mm and a de novo 16q24.1 deletion. We identified nine prenatal cases with a 16q24.1 deletion, all involving the FOXF1 gene or its enhancer region. The main ultrasound findings included increased nuchal translucency and cystic hygroma during the first trimester, and cardiac, renal, and intestinal malformations from 20 weeks of gestation onward. Prenatal diagnosis of ACDMPV based solely on ultrasound findings is challenging. In most reported cases, the pregnancy was carried to term, with the diagnosis being confirmed by post-mortem histopathological examination. In the only case in which the pregnancy was terminated at 14 weeks’ gestation, histological examination of the fetal lungs, despite them being in the early stages of development, revealed misaligned pulmonary veins in close proximity to the pulmonary arteries and bronchioles. Evidence highlights the significance of non-coding regulatory regions in the regulation of FOXF1 expression. Differential methylation patterns, and possible contributions of parental imprinting, highlight the complexity of FOXF1 regulation. Early detection through array comparative genomic hybridization (array CGH) or next-generation sequencing to identify point mutations in the FOXF1 gene, combined with increased awareness of ultrasound markers suggestive of the condition, could improve the accuracy of prenatal diagnosis and genetic counseling. Further research into the epigenetic regulation of FOXF1 is crucial for refining recurrence risk estimates and improving genetic counseling practices. Full article

Background: Osteodysplastic syndromes comprise a very diverse group of clinically and genetically heterogeneous disorders characterized by defects in bone and connective tissue development, as well as in bone density. Here, we report the case of a 48-year-old female with a complex medical history characterized by bone dysplasia, hyperostosis, and partial tooth agenesis. Methods: Genetic testing was performed using WES analysis and Sanger sequencing. Molecular modeling analysis and dynamics simulation explored the impact of detected pathogenic variants. Results: The genetic analysis detected multiple pathogenic variants in genes CREB3L1, SLCO2A1, SFRP4, LRP5, and LRP6, each of which has been associated with rare osteodysplastic syndromes. The patient was homozygous for the same rare alleles associated with three of the identified autosomal recessive disorders osteogenesis imperfecta type XVI, primary hypertrophic osteoarthropathy, and metaphyseal dysplasia Pyle type. She also had a variant linked to autosomal dominant endosteal hyperostosis and a variant previously associated with increased risk of osteoporosis and bone fractures. Two of the detected variants are predicted to cause abnormal splicing, while molecular modeling and dynamics simulations analysis suggest that the other three variants probably confer altered local secondary structure and flexibility that may have functionally devastating consequences. Conclusions: Our case highlights the rare coexistence of multiple osteodysplastic syndromes in a single patient that may complicate differential diagnosis. Furthermore, this case emphasizes the necessity for early genetic investigation of such complex cases with overlying phenotypic traits, followed by genetic counseling, facilitating orchestration of clinical interventions and allowing prevention and/or prompt management of manifestations. Full article

Background: Fanconi Anemia (FA) is a rare disorder, characterized by chromosomal instability, congenital abnormalities, progressive bone marrow failure, and predisposition to cancer. FA is caused by pathogenic variants in any of the 23 (FANCA-FANCY) linked genes. Procedure: Retrospective analysis of 13 FA patients with a causative variant was performed. Patients (6 boys and 7 girls) aged from 9 to 26 years old, (mean age of 7.3 years), at diagnosis. Results: Phenotype evaluation demonstrated in 11/13 patients’ congenital anomalies, with pigmentary changes and short stature, present in 90% of cases. Hematological abnormalities were present in 10/11 patients, with thrombocytopenia being the prominent finding. Genetic analysis for the most common complementation group FA-A revealed that 12/13 patients belonged to this group and only one patient was found to be FA-E. Exon deletions, single nucleotide variations, and duplications were identified. Familial patterns, due to consanguinity, were evident in one case. Twelve patients underwent hematopoietic stem cell transplantation (HSCT), with variable pre-HSCT supportive treatments. Post-HSCT data showed that 9 out of 10 patients for whom follow up data was available, survived for a median time of 5.4 years. Complications like acute graft-versus-host disease were noted. Conclusions: Our study highlights the importance of genotype towards tailored monitoring for children and families with FA. Full article

Background and Clinical Significance: Inherited thrombocytopenia (IT) is a heterogeneous group of disorders caused by mutations in over 45 genes. Among these, ANKRD26-related thrombocytopenia (ANKRD26-RT) accounts for a notable subset and is associated with variable bleeding tendencies and an increased risk of myeloid malignancies. However, the extent of this oncogenic risk appears to vary between specific gene variants. Understanding the genotype–phenotype relationship is essential for patient counseling and management. This report presents a multigenerational family carrying the rare c.−118C > G variant in the 5′ untranslated region of ANKRD26, contributing to the discussion on variant-specific cancer predisposition. Case Presentation: Two sisters aged 57 and 60 presented with lifelong bleeding diathesis and moderate thrombocytopenia. Their symptoms included easy bruising, menorrhagia, and excessive postoperative bleeding. Genetic testing confirmed heterozygosity for the ANKRD26 c.−118C > G variant. Bone marrow analysis revealed abnormal megakaryopoiesis without evidence of dysplasia or somatic mutations. One sister underwent major surgery without complications when managed with prophylactic hemostatic therapy. Their family history included multiple female relatives with similar symptoms, although formal testing was limited. Notably, none of the affected individuals developed hematologic malignancy, and only one developed esophageal cancer, with no current evidence linking this variant to solid tumors. Conclusions: This case underscores the importance of distinguishing between ANKRD26 variants when assessing malignancy risk. While ANKRD26-RT is associated with myeloid neoplasms, the c.−118C > G variant may confer a lower oncogenic potential. Variant-specific risk stratification and genetic counseling are crucial for optimizing surveillance and avoiding unnecessary interventions in low-risk individuals. Full article