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Kidney & Blood Pressure Research Jun 2024A hereditary condition primarily affecting the kidneys and heart has newly been identified: the RRAGD-associated Autosomal Dominant Kidney Hypomagnesemia with... (Review)
Review
BACKGROUND
A hereditary condition primarily affecting the kidneys and heart has newly been identified: the RRAGD-associated Autosomal Dominant Kidney Hypomagnesemia with Cardiomyopathy (ADKH-RRAGD). This disorder is characterized by renal loss of magnesium and potassium, coupled with varying degrees of cardiac dysfunction. These range from arrhythmias to severe dilated cardiomyopathy, which may require heart transplantation. Mutations associated with RRAGD significantly disrupt the non-canonical branch of the mTORC1 pathway. This disruption hinders the the nuclear translocation and transcriptional activity of the transcription factor EB (TFEB) a crucial regulator of lysosomal and autophagic function.
SUMMARY
All identified RRAGD variants compromise kidney function, leading to hypomagnesemia and hypokalemia of various severity. The renal phenotype for most of the variants (i.e. S76L, I221K, P119R, P119L), typically manifests in the second decade of life occasionally preceded by childhood symptoms of dilated cardiomyopathy. In contrast, the P88L variant is associated to dilated cardiomyopathy manifesting in adulthood. To date, the T97P variant has not been linked to cardiac involvement. The most severe manifestations of ADKH-RRAGD, particularly concerning electrolyte imbalance and heart dysfunction requiring transplantation in childhood appear to be associated with the S76L, I221K, P119R variants.
KEY MESSAGES
This review aims to provide an overview of the clinical presentation for ADKH-RRAGD, aiming to enhance o awareness, promote early diagnosis and facilitate proper treatment. It also reports on the limited experience in patient management with diuretics, magnesium and potassium supplements, metformin, or calcineurin- and SGLT2-inhibitors.
PubMed: 38901414
DOI: 10.1159/000539889 -
Epigenetics Dec 2024Machado-Joseph disease (MJD) is an autosomal dominant spinocerebellar ataxia (SCA) caused by a polyglutamine expansion in the ataxin-3 protein, which initiates a cascade...
Machado-Joseph disease (MJD) is an autosomal dominant spinocerebellar ataxia (SCA) caused by a polyglutamine expansion in the ataxin-3 protein, which initiates a cascade of pathogenic events, including transcriptional dysregulation. Genotype-phenotype correlations in MJD are incomplete, suggesting an influence of additional factors, such as epigenetic modifications, underlying the MJD pathogenesis. DNA methylation is known to impact the pathophysiology of neurodegenerative disorders through gene expression regulation and increased methylation has been reported for other SCAs. In this work we aimed to analyse global methylation in MJD carriers. Global 5-mC levels were quantified in blood samples of 33 MJD mutation carriers (patients and preclinical subjects) and 33 healthy controls, matched by age, sex, and smoking status. For a subset of 16 MJD subjects, a pilot follow-up analysis with two time points was also conducted. No differences were found in median global 5-mC levels between MJD mutation carriers and controls and no correlations between methylation levels and clinical or genetic variables were detected. Also, no alterations in global 5-mC levels were observed over time. Our findings do not support an increase in global blood methylation levels associated with MJD.
Topics: Humans; Machado-Joseph Disease; DNA Methylation; Male; Female; Adult; Middle Aged; Mutation; Heterozygote; Case-Control Studies; Ataxin-3; 5-Methylcytosine; Aged; Epigenesis, Genetic
PubMed: 38900099
DOI: 10.1080/15592294.2024.2368995 -
Investigative Ophthalmology & Visual... Jun 2024To analyze the natural history of EFEMP1-associated autosomal dominant drusen (ADD). (Observational Study)
Observational Study
PURPOSE
To analyze the natural history of EFEMP1-associated autosomal dominant drusen (ADD).
METHODS
In this retrospective observational study of molecularly confirmed patients with ADD, data and retinal imaging were extracted from an in-house database. The main outcome measurements were best-corrected visual acuity (BCVA), refraction, and retinal imaging, including quantitative analyses of the outer nuclear layer (ONL) thickness and pigmented epithelium detachment area, as well as qualitative analyses.
RESULTS
The study included 44 patients (34 females and 10 males). The mean ± SD age of symptom onset was 40.1 ± 6.59 years of age (range, 25-52). Fourteen patients were asymptomatic during their entire follow-up. The most common symptoms at presentation were reduced vision (70%) and distortion in central vision (53%). Most subjects were emmetropic. The mean BCVA (logMAR) at baseline was 0.27 ± 0.41 (range, -0.1 to 2.1) in right eyes and was 0.19 ± 0.32 (range, -0.2 to 1.3) in left eyes. After a mean follow-up of 7.9 years, BCVA was reduced to 0.59 ± 0.66 (range, -0.1 to 2.1) in right eyes and 0.5 ± 0.72 (range, -0.1 to 2.4) in left eyes, values that were significantly different than baseline (P < 0.0001 and P < 0.0014, respectively). Fifteen eyes showed active or inactive choroidal neovascularization (CNV). BCVA differed significantly (P = 0.0004) between eyes with and without CNV at a comparable mean age. The ONL had a slow rate of thinning longitudinally, which significantly correlated with BCVA.
CONCLUSIONS
Despite the late onset and relatively good prognosis of ADD, CNVs are more frequent than previously reported and are associated with a worse prognosis. Further research is necessary to elucidate gender associations.
Topics: Humans; Male; Female; Retrospective Studies; Adult; Middle Aged; Visual Acuity; Follow-Up Studies; Retinal Drusen; Extracellular Matrix Proteins; Tomography, Optical Coherence; Refraction, Ocular
PubMed: 38899960
DOI: 10.1167/iovs.65.6.31 -
Cureus May 2024Spastic paraplegia and psychomotor retardation with or without seizures (SPPRS) is a rare neurodevelopmental disorder associated with autosomal recessive mutations in...
Spastic paraplegia and psychomotor retardation with or without seizures (SPPRS) is a rare neurodevelopmental disorder associated with autosomal recessive mutations in the HACE1 gene. This case report presents the clinical features and genetic analysis of an 11-month-old girl and her sister with SPPRS, making it the third reported case in the Middle East and the second in Saudi Arabia. The patient exhibited hypotonia, global developmental delay, speech delay, swallowing difficulties, and recurrent respiratory infections. A homozygous pathogenic variant in the HACE1 gene (p.R664*) was identified through genetic analysis, confirming the diagnosis of SPPRS. This case report emphasizes the importance of considering variations in clinical presentation, especially in rare disorders where only a few cases are reported. Further research and case studies are needed to better understand the complete phenotypic spectrum of SPPRS and its complications.
PubMed: 38899231
DOI: 10.7759/cureus.60642 -
Kidney International Reports Jun 2024Townes-Brocks syndrome (TBS), a rare autosomal dominant genetic condition associated with (Spalt like Transcription Factor 1), is reported to be present in 1:238,000...
INTRODUCTION
Townes-Brocks syndrome (TBS), a rare autosomal dominant genetic condition associated with (Spalt like Transcription Factor 1), is reported to be present in 1:238,000 individuals in the general population. TBS is characterized by the triad of anorectal malformations, dysplastic ears, with or without hearing impairment, and hand or thumb anomalies. Although kidney involvement is less common in TBS, the disease can progress to kidney failure. Here, we sought to characterize the incidence of variants in individuals undergoing broad-based genetic testing with a kidney gene panel and to quantify the presence of (extra)renal features.
METHODS
A retrospective analysis of the genetic data from a 385-gene panel identified cases with a pathogenic (P) or likely pathogenic (LP) variant in . Data including age, features, and disease progression were collected.
RESULTS
Of 35,044 samples, P or LP variants in were identified in 22, yielding a prevalence of 1:1592 among patients tested for monogenic kidney disease, and 1:342 among cases identified with a monogenic kidney disease. Among this cohort, the median patient age was 23 years (range: 3 months-62 years) with chronic kidney disease (CKD) reported in 91% (20/22) of cases. Reported kidney features included renal agenesis/hypoplasia (7/22; 32%), focal segmental glomerulosclerosis (4/22; 18%), and kidney cysts (3/22; 14%). Confirmed extrarenal features included hearing loss and/or ear features (7/22; 32%), anorectal malformations (6/22; 27%) and hand or thumb abnormalities (4/22; 18%). Three patients (3/22; 14%) had both TBS diagnoses and the traditional "triad."
CONCLUSION
Traditionally, a molecular diagnosis was ascertained primarily in individuals presenting with cardinal features of TBS; therefore, individuals with mild or atypical presentations were often overlooked clinically. Our findings reveal that P/LP variants could be a consequential contributor to monogenic kidney disease.
PubMed: 38899216
DOI: 10.1016/j.ekir.2024.03.030 -
Kidney International Reports Jun 2024The Mayo imaging classification model (MICM) requires a prestep qualitative assessment to determine whether a patient is in class 1 (typical) or class 2 (atypical),...
INTRODUCTION
The Mayo imaging classification model (MICM) requires a prestep qualitative assessment to determine whether a patient is in class 1 (typical) or class 2 (atypical), where patients assigned to class 2 are excluded from the MICM application.
METHODS
We developed a deep learning-based method to automatically classify class 1 and 2 from magnetic resonance (MR) images and provide classification confidence utilizing abdominal -weighted MR images from 486 subjects, where transfer learning was applied. In addition, the explainable artificial intelligence (XAI) method was illustrated to enhance the explainability of the automated classification results. For performance evaluations, confusion matrices were generated, and receiver operating characteristic curves were drawn to measure the area under the curve.
RESULTS
The proposed method showed excellent performance for the classification of class 1 (97.7%) and 2 (100%), where the combined test accuracy was 98.01%. The precision and recall for predicting class 1 were 1.00 and 0.98, respectively, with -score of 0.99; whereas those for predicting class 2 were 0.87 and 1.00, respectively, with -score of 0.93. The weighted averages of precision and recall were 0.98 and 0.98, respectively, showing the classification confidence scores whereas the XAI method well-highlighted contributing regions for the classification.
CONCLUSION
The proposed automated method can classify class 1 and 2 cases as accurately as the level of a human expert. This method may be a useful tool to facilitate clinical trials investigating different types of kidney morphology and for clinical management of patients with autosomal dominant polycystic kidney disease (ADPKD).
PubMed: 38899202
DOI: 10.1016/j.ekir.2024.04.002 -
World Journal of Clinical Cases Jun 2024Primary ciliary dyskinesia (PCD) is an inherited autosomal-recessive disorder of impaired mucociliary clearance characterized by chronic respiratory diseases,...
BACKGROUND
Primary ciliary dyskinesia (PCD) is an inherited autosomal-recessive disorder of impaired mucociliary clearance characterized by chronic respiratory diseases, otolaryngological diseases, central nervous system abnormalities, reproductive system abnormalities, and cardiac function abnormalities. General anesthesia in these patients is associated with a higher incidence of respiratory complications than in patients without the disease.
CASE SUMMARY
A 16-year-old male patient was referred to the emergency room complaining of right ankle pain due to distal tibiofibular fracture. Three years prior, he had been diagnosed with PCD. At that time, he had experienced several episodes of pneumonia, sinusitis, and chronic middle ear infections, for which he underwent surgical interventions. At the current admission, he presented with cough and sputum but no other respiratory symptoms. A chest computed tomography scan revealed centrilobular ground-glass opacities in both lower lobes and a calcified nodule in the left lower lobe. For the surgical procedure and postoperative pain management, combined spinal-epidural anesthesia was employed. The patient's postoperative pain score was measured by the numerical rating scale (NRS). On the day of surgery, his NRS was 5 points. By the second postoperative day, the NRS score had decreased to 2-3 points. The epidural catheter was removed on the fourth day following the operation. The patient was subsequently discharged no respiratory complications.
CONCLUSION
We performed combined spinal-epidural anesthesia in a patient with PCD. The patient experienced no additional respiratory complications and was discharged with a low NRS score for pain.
PubMed: 38898834
DOI: 10.12998/wjcc.v12.i17.3183 -
Neurological Research and Practice Jun 2024Retinal vasculopathy with cerebral leukoencephalopathy and systemic manifestations (RVCL-S) is an ultra-rare, autosomal-dominant small vessel disease caused by...
BACKGROUND
Retinal vasculopathy with cerebral leukoencephalopathy and systemic manifestations (RVCL-S) is an ultra-rare, autosomal-dominant small vessel disease caused by loss-of-function variants in the gene TREX1. Recently, elevated serum levels of von Willebrand Factor Antigen (vWF-Ag) pointed to an underlying endotheliopathy, and microvascular ischemia was suggested to contribute to the neurodegeneration in RVCL-S. Aim of this study was to further elucidate the endotheliopathy in RVCL-S.
METHODS
vWF-Ag and ADAMTS-13 activity were repeatedly measured in two patients with genetically confirmed RVCL-S. Renal biopsy of both RVCL-S patients and autoptic brain, renal, hepatic, and pulmonary specimen of one patient with RVCL-S were examined immunohistochemically in comparison to matched controls. In addition, cerebral methylome analysis was performed in the autoptic brain specimen calculating differentially methylated positions compared to controls.
RESULTS
While vWF-Ag and activity was strongly elevated, ADAMTS-13 activity was low in RVCL-S and further decreased over the course of the disease. Autoptic brain specimen showed signs of thromboinflammation in cerebral small vessels, and vWF-Ag staining was strongly positive in cerebral and renal small vessels in RVCL-S, while only a light to moderate vWF-Ag staining was found in controls. Cerebral methylome analysis yielded 115 differentially methylated CpGs (p < 0.05) in the deceased RVCL-S patient compared to the eight controls without brain pathology. One of the hypomethylated genes coded for ADAMTS-13 (p = 0.00056).
CONCLUSIONS
These findings point to an imbalance of the vWF - ADAMTS-13 axis in patients with RVCL-S, that may finally lead to an accumulation of vWF-Ag in renal and cerebral small vessels. Elevated vWF-Ag levels may serve as an early serum marker reflecting disease activity. If confirmed, therapeutic approaches might aim at an inhibition of vWF-Ag or increase of ADAMTS-13 activity in the future.
PubMed: 38898536
DOI: 10.1186/s42466-024-00327-2 -
The Journal of Biological Chemistry Jun 2024Aberrant regulation of signal transduction pathways can adversely derail biological processes for tissue development. One such process is the embryonic eyelid closure...
Aberrant regulation of signal transduction pathways can adversely derail biological processes for tissue development. One such process is the embryonic eyelid closure that is dependent on the Mitogen-Activated Protein Kinase Kinase Kinase 1 (MAP3K1). Map3k1 knockout in mice results in defective eyelid closure and an autosomal recessive eye-open at birth phenotype. We have shown that in utero exposure to dioxin, a persistent environmental toxicant, induces the same eye defect in Map3k1 heterozygous but not wild type pups. Here we explore the mechanisms of the Map3k1 (gene) and dioxin (environment) interactions (GxE) underlying defective eyelid closure. We show that, acting through the Aryl Hydrocarbon Receptor (AHR), dioxin activates Epidermal Growth Factor Receptor (EGFR) signaling, which in turn depresses MAP3K1-dependent Jun N-terminal Kinase (JNK) activity. The dioxin mediated JNK repression is moderate but is exacerbated by Map3k1 heterozygosity. Therefore, dioxin exposed Map3k1 embryonic eyelids have a marked reduction of JNK activity, accelerated differentiation and impeded polarization in the epithelial cells. Knocking out Ahr or Egfr in eyelid epithelium attenuates the open-eye defects in dioxin-treated Map3k1 pups, whereas knockout of Jnk1 and S1pr that encodes the Sphigosin-1-phosphate (S1P) receptors upstream of the MAP3K1-JNK pathway potentiates the dioxin toxicity. Our novel findings show that the crosstalk of AHR, EGFR and S1P-MAP3K1-JNK pathways determines the outcome of dioxin exposure. Thus, gene mutations targeting these pathways are potential risk factors for the toxicity of environmental chemicals.
PubMed: 38897570
DOI: 10.1016/j.jbc.2024.107486 -
European Journal of Medical Genetics Jun 2024Retinoblastoma is the most common eye cancer in children. It is caused by pathogenic alterations of both alleles of the tumor suppressor gene RB1. In heritable...
Retinoblastoma is the most common eye cancer in children. It is caused by pathogenic alterations of both alleles of the tumor suppressor gene RB1. In heritable retinoblastoma, a constitutional RB1 variant predisposes the cells to tumor formation, and loss of the other allele is a prerequisite for the development of retinoblastoma. Heritable retinoblastoma is inherited in an autosomal dominant manner; however, the majority of cases are the result of a de novo pathogenic RB1 variant. Penetrance is usually high (>90%), but with marked inter-familial variability. In some families, penetrance is incomplete and family members who develop tumors tend to remain unilaterally affected. Moreover, some families with low penetrance also show a parent-of-origin effect. We describe a patient with unilateral retinoblastoma caused by a previously unreported likely pathogenic RB1 variant (c.1199T>C) that disrupts a highly conserved amino acid residue within the A-box functional domain. Segregation analysis showed that the variant had unusually low penetrance as nine non-affected family members carried the same variant. We emphasize the use of genetic analysis on tumor DNA for classifying the RB1 variant, and underline the challenges in clinical management and counseling of families carrying the specific RB1 variant.
PubMed: 38897371
DOI: 10.1016/j.ejmg.2024.104956