Phenome- and laboratory-wide meta-analyses of sickle cell trait reveal multi-system disease associations

Sickle cell trait (SCT) is increasingly recognized as a risk factor for adverse health outcomes. We utilized three large US electronic health record-based biobanks (Vanderbilt University Medical Center's BioVU, Penn Medicine Biobank, and All of Us) to conduct phenome-wide association (PheWAS) and clinical laboratory-wide association (LabWAS) meta-analyses of 4,813 individuals with SCT among 58,830 African genetic ancestry participants (∼60% female). Significant associations were replicated using a published PheWAS of SCT from the Million Veteran Program. Our PheWAS meta-analysis confirmed the association of SCT with increased risks of kidney disease, pulmonary embolism, and anemia, while also identifying associations with increased risk of splenomegaly, gout, acute pyelonephritis, and anemia of pregnancy. LabWAS confirmed prior associations of SCT with blood cell counts, red cell indices, kidney function, and urinary concentrating ability. We also identified associations with higher serum electrolytes, bilirubin, and reticulocyte count and lower blood urea nitrogen and platelet count. In sex-stratified analyses, the association of SCT with kidney-related disorders and kidney dysfunction was stronger in females, while the association with platelet and lymphocyte phenotypes was greater in males with SCT. Our results provide insights into the multi-system complications of SCT and have potential clinical implications both for general awareness of susceptibility and appropriate reference ranges for various clinical laboratory parameters in individuals with SCT.