A comprehensive twin study on genetic and nongenetic traits related to the etiologies of schizophrenia.

1.在研究期间发现了一个新的精神分裂症双胞胎样本，包括22个单卵（Mz）和14个双卵（Dz）双胞胎。其中32对出生在长崎县。流行病学调查表明：（1）DSM-III-R精神分裂症（Sz）的双生子符合率为50.0%，与英国和挪威的双生子符合率非常接近;（2）第二胎Mz双生子比第一胎Mz双生子更易患Sz，功能障碍更严重;（3）与Sz（conc-Mz）一致的Mz双胞胎的皮纹不对称性的波动揭示了发育缓冲能力的降低而产前环境损伤导致Mz双胞胎拇指嵴数增加与Sz（disse Mz）不一致.磁共振成像（MRI）的脑形态学研究显示，脑室扩大conc-Mz，而较小的尺寸，左侧海马在受影响的成员的disc-Mz比未受影响。这些结果表明遗传和非遗传因素如产前或围产期损伤参与了Sz性状的发展.双生子样本，特别是盘状Mz，可以作为一个分析系统来测试是否只有基因组DNA可以引起疾病。候选基因突变，如D2 DR错义突变和三重重复扩增以及整个对基因组之间的受影响和非受影响的成员之间的disc-Mz对应用新的分子遗传学技术进行比较。

1. A new schizophrenic twin sample, found during the term of research, consists of 22 monozygotic (Mz) and 14 dizygotic (Dz) twins. Thirty two pairs of them were born in Nagasaki prefecture.2. Epidemiological investigation demonstrated (1) a new twin concordance for DSM-III-R schizophrenia(Sz), 50.0% by probandwise method very close to those from U.K.and Norway, (2) second-born Mz twins were more vulnerable to Sz and dysfunctioned than the first-borns, and (3) a decreased developmental buffer capacity revealed by hjgh fluctuating dermatoglyphic asymmetry in Mz twins concordant for Sz (conc-Mz) while plausible environmental insults in prenatal period resulting in an increase of thumbs' ridge counts in Mz twins discordant for Sz (dise Mz).3. Brain morphological study by magnetic resonance imaging (MRI) revealed ventricular enlargement in conc-Mz while smaller size the left hippocampus in affected member of disc-Mz than the non-affected. These results suggested the involvement of genetic and non-genetic factors such as pre-or perinatal damage in the development of Sz traits.4. Twin sample, especially disc-Mz, can serve as an assay system to test whether only geneomic DNA can cause or disease. Candidate gene mutations such as D2DR missense mutation and triplet repeats expansion as well as entire pair genomes are going to be compared between affected and non-affected members in disc-Mz pairs applying new molecular genetic techniques.