Evaluation of: Burri A, Corina G, Myriam L, Timothy S, Qazi R. A multivariate twin study of female sexual dysfunction. J. Sex. Med. 9, 2671-2681 (2012). This study highlights the complicated nature of female sexual dysfunction (FSD), demonstrating both genetic and environmental factors involved in its etiology. The authors gathered the Female Sexual Function Index scores in a twin population, and examined which dimensions of FSD may be genetically determined or environmentally shared. The results indicate that approximately one-third of the covariance between FSD dimensions was genetic, with one identified loci influencing all phases of the sexual response cycle, whereas the other loci influenced only arousal and orgasm function. They also show that specific types of sexual problems may be related more to nonshared environmental factors. Overall, the results suggest FSD is multifactorial.