english: Approximately 8% of patients diagnosed  with chronic insomnia are actually suffering from a less common genetic problem called delayed sleep phase disorder, or DSPD.
non_english: Približno 8 % pacientov z diagnozo kronične nespečnosti dejansko trpi za manj pogostim genetskim problemom, ki se imenuje motnja faze spanja  ali (z angleško kratico) DSPD.