NHLBI TOPMed: Walk-PHaSST Sickle Cell Disease


The description below was taken directly from the NCBI database of Genotypes and Phenotypes (dbGaP):

This study is part of the NHLBI Trans-Omics for Precision Medicine (TOPMed) Whole Genome Sequencing Program. TOPMed is part of a broader Precision Medicine Initiative, which aims to provide disease treatments that are tailored to an individual's unique genes and environment. TOPMed will contribute to this initiative through the integration of whole-genome sequencing (WGS) and other -omics (e.g., metabolic profiles, protein and RNA expression patterns) data with molecular, behavioral, imaging, environmental, and clinical data. In doing so, this program aims to uncover factors that increase or decrease the risk of disease, to identify subtypes of disease, and to develop more targeted and personalized treatments. Two genotype call sets derived from WGS are now available, Freeze 5b (GRCh38) and Freeze 8 (GRCh38), with largely overlapping sample sets. Information about how to identify other TOPMed WGS accessions for cross-study analysis, as well as descriptions of TOPMed methods of data acquisition, data processing and quality control, are provided in the accompanying documents, "TOPMed Whole Genome Sequencing Project - Freeze 5b, Phases 1 and 2" and "TOPMed Whole Genome Sequencing Project - Freeze 8, Phases 1-4". Please check the study list at the top of each of these methods documents to determine whether it applies to this study accession.

Walk-PHaSST study is a multi-center clinical trial to evaluate the effects of sildenafil on Sickle Cell Disease (SCD) population with low exercise capacity associated with an increased Doppler-estimated pulmonary artery systolic pressure (as assessed by the tricuspid regurgitant velocity (TRV)). It is a double-blind, placebo-controlled trial to assess the safety, tolerability, and efficacy of sildenafil in patients with SCD who had both an elevated TRV and decreased exercise capacity. The screening phase of the study enrolled 720 subjects and 74 of them were randomized for the clinical trial. For the screening cohort, we have collected general demographics and race/ethnicity, hemoglobin genotype, physical examination, laboratory screening, transthoracic Doppler echocardiography, and 6 minute walk test in 9 US and 1 UK site. The walk-PHaSST biorepository have banked samples from 610 of the screening subjects. A total of 592 subjects from the screening phase are included in the TOPMed program for WGS.

General information

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