In this study, we aimed to estimate pubertal milestones in 37 PWS patients (18 females) with median age 11.1 (95% CI: 6.4 – 18.8) years on the background of recent normative data, to correlate bone age (BA) and gonadarche onset and evaluate the link between variant pubarche and gonadarche and the MKRN3 gene sequence or expression level in individual genetic subtypes of PWS. The gene discussed is MKRN3; the disease is Prader-Willi syndrome.