Characteristic, clinical features, typical for Wolf-Hirschhorn syndrome (WHS) were presented in the article. It is caused by partial deletion of the short arm of chromosome 4. The authors paid special attention to cytogenetic and molecular diagnostics of WHS. We mentioned some information concerning the search for the genes responsible for WHS features. Starting from making a connection between the syndrome phenotype and cytogenetic abnormalities, through gradual shortening of the length of the critical region WHSCR (finally up to 165 kb), and sequencing it, at least 2 genes (WHSC1 and WHSC2) were identified.