The top variant associated with comorbid GERD and COPD in the combined NHW participants was 4:116174264 [OR = 1.59, 95% CI = 1.45–1.74, P = 3.24E-07, S4 Table], which is intergenic to NDST4 and MIR1973. This evidence concerns the gene NDST4 and gastroesophageal reflux disease.