The article suggests a possible model where the schizophrenia is an extreme linear progression. But the inability to find a culprit genes suggests something more complex. It is possible that there are is a group of genes that all have variations that confers benefit, but when those variations are all together negative effects occur. That makes the positive variants overall beneficial, and keeps them in the gene pool. This is why it is dangerous to presume that when we correlate genetic variants with disease and then presume they should go away. In fact, nearly any inherited disease that has survived may be conferring value to other individual when in proper partnership with other genetic profiles.
replies(1):