Nowadays, there is an emerging need for the development of computationally efficient virtual population generators for large-scale clinical trials. In this work, we utilize Gaussian Mixture Models (GMM) with variational Bayesian inference (BGMM) using robust estimations of Dirichlet concentration priors for the generation of virtual populations. The estimations were based on an exponential transformation of the number of Gaussian components. The proposed method was compared against state-of-the-art virtual data generators, such as, the Bayesian networks, the supervised tree ensembles (STE), the unsupervised tree ensembles (UTE), and the artificial neural networks (ANN) towards the generation of 20000 virtual patients in hypertrophic cardiomyopathy (HCM) clinical trials. Our results suggest that the proposed BGMM can yield virtual distributions with small inter-and intra-correlation difference (0.013 and 0.012), in less execution time (0.432 sec) than the STE which achieved the second-best performance.