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- Fresard, Laure, et al.
(författare)
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Identification of rare-disease genes using blood transcriptome sequencing and large control cohorts
- 2019
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Ingår i: Nature Medicine. - : NATURE PUBLISHING GROUP. - 1078-8956 .- 1546-170X. ; 25:6, s. 911-919
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Tidskriftsartikel (refereegranskat)abstract
- It is estimated that 350 million individuals worldwide suffer from rare diseases, which are predominantly caused by mutation in a single gene(1). The current molecular diagnostic rate is estimated at 50%, with whole-exome sequencing (WES) among the most successful approaches(2-5). For patients in whom WES is uninformative, RNA sequencing (RNA-seq) has shown diagnostic utility in specific tissues and diseases(6-8). This includes muscle biopsies from patients with undiagnosed rare muscle disorders(6,9), and cultured fibroblasts from patients with mitochondrial disorders(7). However, for many individuals, biopsies are not performed for clinical care, and tissues are difficult to access. We sought to assess the utility of RNA-seq from blood as a diagnostic tool for rare diseases of different pathophysiologies. We generated whole-blood RNA-seq from 94 individuals with undiagnosed rare diseases spanning 16 diverse disease categories. We developed a robust approach to compare data from these individuals with large sets of RNA-seq data for controls (n = 1,594 unrelated controls and n = 49 family members) and demonstrated the impacts of expression, splicing, gene and variant filtering strategies on disease gene identification. Across our cohort, we observed that RNA-seq yields a 7.5% diagnostic rate, and an additional 16.7% with improved candidate gene resolution.
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| 2. |
- Gkourogianni, Alexandra, et al.
(författare)
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Clinical characterization of patients with autosomal dominant short stature due to aggrecan mutations
- 2017
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Ingår i: Journal of Clinical Endocrinology and Metabolism. - Cary, USA : Oxford University Press. - 0021-972X .- 1945-7197. ; 102:2, s. 460-469
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Tidskriftsartikel (refereegranskat)abstract
- Context: Heterozygous mutations in the Aggrecan gene (ACAN) cause autosomal dominant short stature with bone age (BA) acceleration, premature growth cessation and minor skeletal abnormalities.Objective: Characterize the phenotypic spectrum, associated conditions and response to growth-promoting therapies.Design: Retrospective international cohort study.Patients: Information from 103 individuals (57 female, 46 male) from 20 families with confirmed heterozygous ACAN mutations were included.Methods: Families with autosomal dominant short stature and heterozygous ACAN mutations were identified and confirmed using whole-exome sequencing, targeted next generation sequencing, and/or Sanger sequencing. Clinical information was collected from medical records.Results: Identified ACAN variants showed perfect co-segregation with phenotype. Adult individuals had mildly disproportionate short stature (median height: -2.8 SDS, range: -5.9 to -0.9) and histories of early growth cessation. The condition was frequently associated with early-onset osteoarthritis (12 families) and intervertebral disc disease (9 families). There was no apparent genotype-phenotype correlation between type of ACAN mutation and presence of joint complaints. During childhood, height was less affected (median height: -2.0 SDS, range: -4.2 to -0.6). In contrast to most children with short stature, the majority of children had advanced BA (BA - CA, median: +1.3y; range +0.0 to +3.7y) reflecting a reduction in remaining growth potential. Nineteen individuals had received GH with some evidence of increased growth velocity.Conclusions Heterozygous ACAN mutations result in a phenotypic spectrum ranging from mild and proportionate short stature to a mild skeletal dysplasia with disproportionate short stature and brachydactyly. In several of the families, affected individuals developed early-onset osteoarthritis and degenerative disc disease requiring intervention, suggesting dysfunction of articular cartilage and intervertebral disc cartilage. Additional studies are needed to determine the optimal treatment strategy for these patients.
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