Nejvíce citovaný článek - PubMed ID 38096951
Autosomal dominant ApoA4 mutations present as tubulointerstitial kidney disease with medullary amyloidosis
BACKGROUND: ADTKD-MUC1 is caused by frameshift mutations in MUC1 gene that produce a frameshifted protein (MUC1fs) toxic to kidney cells. The gene's variable number of tandem repeats (VNTR), with high GC content, makes it largely inaccessible to standard sequencing. As a result, both the reference sequence and natural variation in this region remain poorly defined, complicating mutation detection and data interpretation. Standard methods also fail to pinpoint the exact VNTR unit affected, limiting insight into mutation mechanisms and genotype-phenotype correlations. METHODS: We employed Single Molecule, Real-Time (SMRT) sequencing and characterized the genomic sequence of MUC1 in 300 individuals including 279 individuals from 143 families suspected of having ADTKD-MUC1. We compared these results to those obtained using the CLIA-approved mass spectrometry-based probe extension (PE) assay, which specifically detect the most prevalent 59dupC mutation. We correlated the structural features of the MUC1 VNTR with the rate of kidney function decline in affected individuals. RESULTS: We identified MUC1 consensus sequences for 205 unique VNTR alleles, with 9 distinct types of frameshift mutations present on 52 distinct mutated VNTR alleles. MUC1 frameshift mutations were identified in 71 of 143 families (50%) with suspected ADTKD, comprising 135 genetically affected individuals (48%). The SMRT assay exhibited complete concordance and revealed that the PE assay is capable of detecting frameshift mutations in approximately 85% of affected families. The constellation of VNTR structures supports a genotype-progression model, in which fast progressors exhibit a significantly lower number of repeat units on the wild-type allele and a higher number of repeats on the mutation-bearing allele, including an increased number of frameshifted repeat units. CONCLUSIONS: SMRT sequencing outperforms current diagnostic methods for ADTKD-MUC1 and reveals the prognostic value of VNTR structures. Although their contribution to disease progression is modest (~6% variance explained), it remains biologically and clinically meaningful.
Background: Genetic causes of chronic diseases, once considered rare in adult-onset disease, now account for between 10 and 20% of cases of chronic kidney disease (CKD). Confirming a genetic diagnosis can influence disease management; however, the utility of genetic testing in older adults remains poorly understood, partly due to age-based restrictions on testing access. To better evaluate the diagnostic yield and clinical utility of genetic testing in this population, we analyzed data from adults aged ≥50 years with CKD who were assessed in a specialized kidney genetics clinic. Methods: We studied a cohort of 125 adults with CKD aged ≥50 years at the time of genetic testing. Genetic testing included gene panels targeting disease-related genes based on clinical phenotype, and/or exome sequencing for additional monogenic causes if the initial panel testing was inconclusive. Results: Pathogenic variants in disease-related genes were identified in 38% of patients. The highest diagnostic yield (48%) was in patients aged 50-54 years. The most common diagnosis post-testing was glomerulopathies (32%). Clinical utility, shown through the case series, included modifications to treatment and clinical management, as well as a reduction in the diagnostic odyssey. Conclusions: Our findings from a dedicated Kidney Genetics Clinic show that genetic testing in adults ≥50 years with CKD has significant diagnostic and clinical utility. These results support guideline recommendations that there should be no upper age limit for genetic testing. Future research in unselected CKD populations is needed to establish the broader applicability and feasibility of genetic testing in older adults.
- Klíčová slova
- chronic kidney disease, exome sequencing, genetic kidney disease, genetic testing, older adults,
- MeSH
- chronická renální insuficience * genetika diagnóza MeSH
- genetická predispozice k nemoci MeSH
- genetické testování * metody MeSH
- lidé středního věku MeSH
- lidé MeSH
- sekvenování exomu MeSH
- senioři nad 80 let MeSH
- senioři MeSH
- Check Tag
- lidé středního věku MeSH
- lidé MeSH
- mužské pohlaví MeSH
- senioři nad 80 let MeSH
- senioři MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
