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Genetic heterogeneity of schizophrenia
14A
BIOL PSYCHlATRY 1989;25:14A-18A
NEUROBIOLOGY
Neurobiology of Schizophrenia
OF SCHIZOPHRENIA
Thursday, May 4, 1%) to 4:00 Continental Ballroom 9
29
GENETIC HETEROGENEITY OF SCHIZOPHRENIA Harald Aschauer, Gabriele Aschauer-Treiber, C. Robert Cloninger, David L. Garver, Keith E. Isenberg St. Louis, MO
Linkage of chromosome 5 loci and schizophrenia has been described in several Icelandic and British pedigrees (Sherrington et al., Nature 336:164, 1988). But linkage of illness and chromosome 5 loci has not been found in an extensively studied Scandinavian pedigree (Kennedy et al., Nature 336: 167, 1988). These results are compatible with genetic heterogeneity underlying schizophrenia. We report preliminary analysis concerning a possible association of a locus on chromosomes 2 and DSM-III schizophrenia in seven pedigrees. The analysis was performed using Liped under conditions of gene frequency of 0.0006, homozygous and heterozygous affected penetrance of 0.7, and homozygous unaffected penetrance of 0.0001. Total lod score for linkage of schizophrenia and the chromosome 2 probe was - 1.79 at 0.0 recombination. Under the assumption of genetic heterogeneity, four pedigrees evidenced an association of the chromosome 2 locus and schizophrenia (lod 2.34). Three pedigrees failed to demonstrate such linkage (lod score - 4.12). These pedigrees are concurrently being examined for linkage of schizophrenia and loci on chromosome 5. Resolution of genetic heterogeneity requires consideration of genetic and clinical parameters.
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PERINATAL COMPLICATIONS AND SUPERIOR POSTERIOR VERMIAN HYPOPLASIA IN SCHIZOPHRENIA ON MRI SCANS Henry A. Nasrallah, Steven B. Schwarzkopf, Jeffrey A. Coffman, Steven C. Olson Columbus, OH Although cerebellar “atrophy” has been reported in some schizophrenics, the frequency has been inconsistent and the meaning of the finding remains obscure. Recently, Courchesne et al. (1988) reported that a developmentally specific cerebellar vermian region (Lobules VI and VII) in autism was hypoplastic. We therefore hypothesized that schizophrenics with a history of developmental brain insult (i.e. perinatal complications) are more likely to have hypoplasia of the superior posterior vermis (Lobules VI and VII) compared to other schizophrenics. Thirty schizophrenic males were studied. A structured perinatal questionnaire was administered to their mothers. MRI scans were obtained (1.5 Tesla, Ti-weighted) and the areas of the three vermian regions were traced and measured. The mean area of Lobules VI and VII in the perinatally “damaged” group was significantly smaller than in the “undamaged” group (2.75 ? .59 vs 3.33 + 1.15, p = .041, one tailed t-test). Lobules I-V and VIII to X were not different between the groups. These findings confirm the hypothesis that a specific regional hypoplasia of the cerebellum vermis may be associated with perinatal complications in schizophrenia. The findings may shed light on the pathogenesis of vermian hypoplasia in schizophrenia.
BIOL PSYCHlATRY 1989;25:14A-18A
NEUROBIOLOGY
Neurobiology of Schizophrenia
OF SCHIZOPHRENIA
Thursday, May 4, 1%) to 4:00 Continental Ballroom 9
29
GENETIC HETEROGENEITY OF SCHIZOPHRENIA Harald Aschauer, Gabriele Aschauer-Treiber, C. Robert Cloninger, David L. Garver, Keith E. Isenberg St. Louis, MO
Linkage of chromosome 5 loci and schizophrenia has been described in several Icelandic and British pedigrees (Sherrington et al., Nature 336:164, 1988). But linkage of illness and chromosome 5 loci has not been found in an extensively studied Scandinavian pedigree (Kennedy et al., Nature 336: 167, 1988). These results are compatible with genetic heterogeneity underlying schizophrenia. We report preliminary analysis concerning a possible association of a locus on chromosomes 2 and DSM-III schizophrenia in seven pedigrees. The analysis was performed using Liped under conditions of gene frequency of 0.0006, homozygous and heterozygous affected penetrance of 0.7, and homozygous unaffected penetrance of 0.0001. Total lod score for linkage of schizophrenia and the chromosome 2 probe was - 1.79 at 0.0 recombination. Under the assumption of genetic heterogeneity, four pedigrees evidenced an association of the chromosome 2 locus and schizophrenia (lod 2.34). Three pedigrees failed to demonstrate such linkage (lod score - 4.12). These pedigrees are concurrently being examined for linkage of schizophrenia and loci on chromosome 5. Resolution of genetic heterogeneity requires consideration of genetic and clinical parameters.
30
PERINATAL COMPLICATIONS AND SUPERIOR POSTERIOR VERMIAN HYPOPLASIA IN SCHIZOPHRENIA ON MRI SCANS Henry A. Nasrallah, Steven B. Schwarzkopf, Jeffrey A. Coffman, Steven C. Olson Columbus, OH Although cerebellar “atrophy” has been reported in some schizophrenics, the frequency has been inconsistent and the meaning of the finding remains obscure. Recently, Courchesne et al. (1988) reported that a developmentally specific cerebellar vermian region (Lobules VI and VII) in autism was hypoplastic. We therefore hypothesized that schizophrenics with a history of developmental brain insult (i.e. perinatal complications) are more likely to have hypoplasia of the superior posterior vermis (Lobules VI and VII) compared to other schizophrenics. Thirty schizophrenic males were studied. A structured perinatal questionnaire was administered to their mothers. MRI scans were obtained (1.5 Tesla, Ti-weighted) and the areas of the three vermian regions were traced and measured. The mean area of Lobules VI and VII in the perinatally “damaged” group was significantly smaller than in the “undamaged” group (2.75 ? .59 vs 3.33 + 1.15, p = .041, one tailed t-test). Lobules I-V and VIII to X were not different between the groups. These findings confirm the hypothesis that a specific regional hypoplasia of the cerebellum vermis may be associated with perinatal complications in schizophrenia. The findings may shed light on the pathogenesis of vermian hypoplasia in schizophrenia.