Mapping breakpoints in patients with de novo balanced chromosomal translocation (BCTs) offers a unique possibility for identification of new genes causing human monogenic disorders, even when only single patients are studied. Historically, solving the exact structure of BCTs was laborious, but with the emergence of next generation sequencing (NGS) it became possible to rapidly map the breakpoints with a resolution up to 1bp. Using shallow mate pair genomic sequencing we report the structure of BCTs in 9 probands with special emphasis on patients with disrupted genes that so far have not been linked to human disorders (EFNA5, BAHD1 and PPP2R5E). (By Prof. dr hab. Rafal Ploski, https://jmg.bmj.com/content/early/2018/10/23/jmedgenet-2018-105527 )