AbstractMotivationQuantitative trait locus (QTL) analysis of multiomic molecular traits, such as gene transcription (eQTL), DNA methylation (mQTL) and histone modification (haQTL), has been widely used to infer the effects of genomic variation on multiple levels of molecular activities. However, the power of xQTL (various types of QTLs) detection is largely limited by missing association statistics due to missing genotypes and limited effective sample size. Existing hidden Markov model (HMM)-based imputation approaches require individual-level genotypes and molecular traits, which are rarely available. No available implementation exists for the imputation of xQTL summary statistics when individual-level data are missed.ResultsWe present xQTLImp, a C++ software package specifically designed for efficient imputation of xQTL summary statistics based on multivariate Gaussian approximation. Experiments on a single-cell eQTL dataset demonstrates that a considerable amount of novel significant eQTL associations can be rediscovered by xQTLImp.AvailabilitySoftware is available at https://github.com/hitbc/xQTLimp.Contactydwang@hit.edu.cn or jiajiepeng@nwpu.edu.cnSupplementary informationSupplementary data are available at Bioinformatics online.