Clinical chemistry最新文献

Background: Tandem repeats (TRs) are abundant in the human genome and associated with repeat expansion disorders. Our study aimed to develop a tandem repeat panel utilizing targeted long-read sequencing to evaluate known TRs associated with these disorders and assess its clinical utility.

Methods: We developed a targeted long-read sequencing panel for 70 TR loci, termed dynamic mutation third-generation sequencing (dmTGS), using the PacBio Sequel II platform. We tested 108 samples with suspected repeat expansion disorders and compared the results with conventional molecular methods.

Results: For 108 samples, dmTGS achieved an average of 8000 high-fidelity reads per sample, with a mean read length of 4.7 kb and read quality of 99.9%. dmTGS outperformed repeat-primed-PCR and fluorescence amplicon length analysis-PCR in distinguishing expanded from normal alleles and accurately quantifying repeat counts. The method demonstrated high concordance with confirmatory methods (rlinear = 0.991, P < 0.01), and detected mosaicism with sensitivities of 1% for FMR1 CGG premutation and 5% for full mutations. dmTGS successfully identified interruptive motifs in genes that conventional methods had missed. For variable number TRs in the PLIN4 gene, dmTGS identified precise repeat counts and sequence motifs. Screening 57 patients with suspected genetic muscular diseases, dmTGS confirmed repeat expansions in genes such as GIPC1, NOTCH2NLC, NUTM2B-AS1/LOC642361, and DMPK. Additionally, dmTGS detected CCG interruptions in CTG repeats in 8 myotonic dystrophy type 1 patients with detailed characterization.

Conclusions: dmTGS accurately detects repeat sizes and interruption motifs associated with repeat expansion disorders and demonstrates superior performance compared to conventional molecular methods.

Background: Small remnants may penetrate the arterial intima more efficiently compared to large triglyceride-rich lipoproteins (TGRL). We tested the hypothesis that the importance of remnant cholesterol for the risk of atherosclerotic cardiovascular disease (ASCVD) may depend on the size of the remnants and TGRL carrying cholesterol.

Methods: The cholesterol content of small remnants and large TGRL were measured in 25 572 individuals from the Copenhagen General Population Study (2003-2015) and in 222 721 individuals from the UK Biobank (2006-2010) using nuclear magnetic resonance spectroscopy. In the Copenhagen cohort during up to 15 years of follow-up and in the UK Biobank cohort during up to 16 years of follow-up, the numbers of individuals diagnosed with ASCVD (=myocardial infarction, ischemic stroke, and peripheral artery disease) in national health registries were 3869 and 11 424, respectively.

Results: Compared to individuals with low cholesterol content in both small remnants and large TGRL (cutpoints were median cholesterol content), multivariable-adjusted hazard ratios for risk of ASCVD were 1.21 (95% confidence interval: 1.07-1.37) for individuals with high cholesterol content in small remnants only and 0.94 (0.83-1.07) for individuals with high cholesterol content in large TGRL only; the multivariable-adjusted hazard ratio for risk of ASCVD per 10 percentile-units higher cholesterol content in small remnants vs that in large TGRL was 1.04 (1.01-1.07). In the UK Biobank cohort, corresponding hazard ratios were 1.11 (1.03-1.20), 1.01 (0.93-1.09), and 1.05 (1.04-1.07), respectively.

Conclusion: The importance of remnant cholesterol for the risk of ASCVD may depend on the size of the TGRL and remnants carrying cholesterol.