<s docid="LA101690-0121" num="10"> Researchers, for example, know that genetic factors are linked to autism and some learning disabilities; that head injury or exposure to toxic substances puts some children at risk for behavior disorders; that psychological trauma, such as physical or sexual abuse, increases the risk of such mental illnesses as multiple-personality disorder.</s>

<s docid="LA101690-0121" num="14"> * Biological risk factors, including genetic defects; very low birth weight; chronic physical conditions, such as deafness or blindness; illness, such as diabetes or asthma; physical trauma, or exposure to toxic chemicals or drugs.</s>

<s docid="LA060589-0049" num="33"> The long-term debate over the cause of Alzheimer's disease continues, with scientists suggesting genetic, viral and environmental origins, or a combination.</s>

<s docid="LA100889-0040" num="181"> But now we have one last, new twist: in the '80s it has been decisively shown that some individuals are genetically predisposed to the development of alcoholism.</s>

<s docid="FT921-11140" num="40"> Genetic testing may reveal an unusual susceptibility to alcoholism or schizophrenia, heart attack or lung cancer, but predictions may be uncertain.</s>

<s docid="LA062590-0042" num="52"> Carson also pointed out that even genetic researchers concede that nearly 90% of schizophrenic patients have no close relatives with the disorder.</s>

<s docid="LA062590-0042" num="53"> Most researchers believe that some genetically vulnerable individuals react badly to stress, which means that both biology and environment contribute to the appearance of schizophrenia.</s>

<s docid="LA112090-0153" num="29"> For example, the recent cystic fibrosis discovery pinpointed the gene in a key protein that malfunctions in patients with the disease.</s>

<s docid="LA112090-0153" num="42"> Kunkel. In 1987, Kunkel's research team discovered the gene that causes Duchenne muscular dystrophy, a disorder that causes muscle weakness and eventually cripples.</s>

<s docid="LA093089-0065" num="69"> Researchers had already determined that manic depression seemed to be a genetically inherited characteristic, passed along in families from one generation to the next.</s>

<s docid="FT934-1290" num="10"> During 1993, the world's researchers have found the precise genetic cause of scores of inherited diseases, including Huntington's chorea, a type of dementia, and several forms of cancer.</s>

<s docid="FT922-715" num="56"> In the case of Alzheimer's, a fault in a gene coding for amyloid precursor protein (APP) seems to be responsible.</s>

<s docid="FT932-7262" num="20"> But inherited genetic defects probably account for only 10 to 15 per cent of Alzheimer's cases.</s>

<s docid="FT932-7262" num="23"> There is more evidence linking severe head injury to the development of Alzheimer's.</s>

<s docid="LA100790-0251" num="41"> Particularly strong was the correspondence between twins for the personality trait that corresponds closely to sensation seeking.</s>

<s docid="LA100790-0251" num="103"> Adds John Payne, a professor of business administration at Duke University, who studies how businesses handle risk, "I think there's more to be understood by looking at the environment in which people are working," rather than at personality differences.</s>

<s docid="LA070590-0178" num="33"> Among people with early hearing loss, Chatterton said about 25% involve a genetic disorder such as Corkhill's.</s>

<s docid="FT922-7420" num="21"> Genetic mapping shows that, for some families, the gene responsible is on chromosome 21.</s>

<s docid="LA111689-0162" num="11"> Researchers from the National Institute of Mental Health and UC San Diego report in today's Nature that they were unable to confirm previous data linking manic-depressive illness -- which causes as many as 2 million Americans to experience radical mood swings between elation and depression -- to a faulty gene.</s>

<s docid="LA111689-0162" num="42"> In fact, researchers have always argued that mental illnesses, with their great variability, are probably caused by more than one gene.</s>

<s docid="LA111689-0162" num="47"> They reported that the suspected schizophrenia gene seemed to lie between two well-known genes on chromosome 5.</s>

<s docid="FR940817-2-00228" num="46"> Alzheimer-type syndromes have been reported in individuals occupationally exposed to organic solvents or metal vapors (Freed and Kandel, 1988).</s>

<s docid="LA101290-0115" num="12"> It indicates that the broad outlines of personality and behavior are put in place in the brief instant when the mother's and father's genes mix during conception, establishing the basic route that the child will take during the rest of its life.</s>

<s docid="LA101290-0115" num="13"> Nurture -- the family environment -- plays a much smaller role, according to the study, published today in the journal Science.</s>

<s docid="LA101290-0115" num="27"> The researchers found that 70% of the intelligence quotient -- IQ -- is accounted for by genes, the strongest correlation found for any characteristic.</s>

<s docid="LA101290-0115" num="28"> Genetics also accounts for about 50% of personality differences, including traits such as extroversion; 50% of religiosity, including how often someone attends religious events, and about 40% for job interest variations.</s>

<s docid="LA032290-0148" num="11"> Studying pairs of twins in which only one had the mental disorder, researchers from the National Institute of Mental Health report today in the New England Journal of Medicine that the afflicted twin in virtually all cases had a slightly smaller brain in certain key areas, suggesting a non-genetic abnormality in growth of the brain during development.</s>

