Genetics and the mystery of Schizophrenia: What lies ahead….Author: Mustafa AbbasGenomics, Bioinformatics and medicine(Biochem 118Q)Spring 2002Professor Douglas BrutlagThe Family IllnessI had so many reasons not to think about schizophrenia, about the terror it caused me as achild. When I was six, I watched my brilliant brother change from an engaging 16-year-old to a zombie who stared into space for hours. Two years later, I saw my older sisterturn cruel and loud, screaming for what seemed like hours. I was too young to knowanything about schizophrenia, but I knew something was terribly wrong. Like many withthis disease, neither my brother or sister could find satisfactory treatment, resulting in mybrother's leaping off a cliff to his death and in the regular recurrence of my sister'spsychotic rages.Schizophrenia isn't the multiple personality of movie stereotype, but it is a horriblemental illness, causing aural hallucinations and provoking paranoid delusions that canmake peculiar behavior seem normal to the sufferer. It often can be treated, but it isn't yetcurable. And although public awareness of mental illness has come a long way in mylifetime, it's difficult not to feel cursed by the shadows it casts.For much of my life, I have tried to believe that the madness was behind me. After all,my brother committed suicide 15 years ago, while I was still in college, and I've been outof touch with my sister for close to 20 years. They no longer inhabit my present life, buttheir illnesses haunt me like ghosts.At this point in my life, that ghost has taken on a terrifying new shape. It haunts me nowwith the question: Would I have a child with schizophrenia? Talking with geneticists didnot dispel my fears; in fact I soon learned that any children of mine would indeed havean increased risk of developing the illness that destroyed my siblings' lives. Although myfiancé has no relatives with schizophrenia, our kids would be as much as eight timesmore likely than the average person to have schizophrenia. But even for my children,schizophrenia is not a huge risk - their chances range from 3 to 8 percent. In the generalpopulation, schizophrenia occurs in one out of every hundred people. Several scientiststold me that other considerations - such as the fact that both my siblings hadschizophrenia - may increase the odds. Another factor could be the severity of mysibling's cases: Both became wildly, uncontrollably ill.These odds are all the scientists can offer me. Unlike some other hereditary diseases, thegenes for schizophrenia have not yet been isolated; there is no test. All we can provideare our family histories; all we can get in return are percentages.If only the science were further along. Still, we try desperately to read our futures in thelittle information we have. The genetics of mental illness will be much better understoodin 20 years, scientist say, but there isn't much chance of current research having practicalapplications within the next five years - when it would be useful to me. In the end, I haveto face the fact that no one can tell me whether a child of mine would be healthy or ill.And so the dilemma remains, particularly for people like me who carry the memories ofour siblings at the same time that we feel the pressure of encroaching age. We cannotwait for research to provide the answers. We must make our peace - and our decisions -with the knowledge at hand.______________________Clea Simon is an editor at the Boston Globe. This piece is adapted from her recentlyreleased book, Mad House: Growing Up in the Shadow of Mentally Ill Siblings(Doubleday), portions of which appeared in The Washington Post.Schizophrenia (SZ) is perhaps the most debilitating and tragic mental illness known. Itleads to a complete breakdown of personality, and for many of its sufferers, is a lifesentence without hope of parole. It effects at least 1% of the population worldwideregardless of race, gender and economic condition. Symptoms usually develop duringyoung adulthood and continue to haunt its sufferers for their lifetime. Positive symptomsinclude delusions, hallucinations and disordered thought, while the negative symptomsare social withdrawal and emotional flattening. Complete recovery from the psychoticand emotional symptoms is very rare. Unfortunately, the illness is also perhaps the mostelusive and mysterious among the mental afflictions in terms of its molecular,environmental and genetic etiology. Moreover, the symptoms manifest themselves insuch varying degrees of qualitative and quantitative intensity, that it very hard to define aspecific set of symptoms and behaviors associated with SZ. Some researchers evensuggest a mental health continuum from depression to bipolar depression toschizophrenia and varying intensity within its symptoms, rather than looking at the illnessas a discretely defined entity. There is presently no biological test that can confirm thepresence of the illness.Schizophrenia is a complex multifactor disorder, and like other multifactordisorders such as cancer, does not follow classical mendelian inheritance patterns. Thegenetics of Schizophrenia, lika almost every mental disorder, are indeed very complex.Twin and family studies have revealed, however, that there is indeed a geneticcomponent to the development of predisposition and finally to the manifestation ofpositive and negative symptoms of SZ. Therefore, families with one ill member have agreater chance of developing this illness later on. It has been hypothesized by manyresearchers that 60% of the factors that give rise to Schizophrenia may be related togenetic susceptibility. However, researchers have not yet been able to identify a singlepredominant “SZ gene” . This is complicated by studies that show that there is infact nosingle gene but a combination of genes acting with small effect to lead to thedevelopment of predisposition and pathology; and the more genes necessary for thedisorder, the harder it is to detect any one of them. Furthermore, there is evidence thatenvironmental factors interact with genetic predisposition in subtle ways for this inheritedsusceptibility to actually develop into a full-blown Schizophrenic psychosis. The natureof these non-genetic effects is yet another mystery that futher complicates the search fordistinct causal factors.There is great hope, however, that by locating genes that are centralto the development of familial predisposition to SZ, we will get clues
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