Scientists said studying such abnormalities may help them find new medications by shedding light on what causes the disease. And if enough rare aberrations can be found eventually, they may be combined into a test to help in diagnosis, said Kari Stefansson, chief executive officer of deCode Genetics of Reykjavik, Iceland, and an author of one of the studies. Schizophrenia is currently diagnosed by its symptoms. The human DNA can be thought of as a very long string of letters — about 3 billion of them — that sometimes form words (genes). Each newly identified deletion removes a section of about half a million to 2 million letters. In the past, scientists have found specific genes and deletions linked to schizophrenia risk. But the new work is notable because two large studies independently identified the same two DNA deletions, and those aberrations have such a big impact on disease risk. Stefansson's paper also reports evidence for a third deletion. *** Read more at: http://news.yahoo.com/s/ap/20080730/ap_on_he_me/med_schizophrenia_genetics