ABNORMAL BEHAVIOR
SCHIZOPHRENIA
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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6%
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9%
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13%
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17%
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Detailed explanation-1: -The pair-wise concordance rates in schizophrenia are 30–40% in MZ and 5–10% in DZ, with somewhat higher rates for proband concordance.
Detailed explanation-2: -[2] Analyzing classic studies of the genetics of schizophrenia done as early as in 1930s, Fischer concludes that a concordance rate for psychosis of about 50% in monozygotic twins seems to be a realistic estimate, which is significantly higher than that in dizygotic twins of about 10–19%.
Detailed explanation-3: -All twin studies found a higher concordance rate for schizophrenia in monozygotic (MZ) than dizygotic (DZ) twins. In Gottesman and Shield’s own study the rate was 58% for identical twins, and 12% for non-identical twins.
Detailed explanation-4: -The concordance rates of 48% for MZ twins and 4% for DZ twins indicate a genetic transmission of DSM-III-R schizophrenia.