宁强试验区精神发育迟滞的遗传方式初探

A Preliminary study of genetic model in mental retardation in Ningqiang experimental station

目的为探明秦巴山区宁强试验区精神发育迟滞的致病原因,初步探讨该地区克汀病与亚克汀病和非特异性精神发育迟滞两种类型家系的遗传方式。方法通过分离分析及多基因阈值理论计算克汀病与亚克汀病和非特异性精神发育迟滞各种婚配类型的校正分离比及遗传率。结果克汀病与亚克汀病的U×U,U×A婚配类型的校正分离比分别为21.37%和45.63%,遗传率为79.00±7.51%,而非特异性精神发育迟滞的各种婚配类型的校正分离比偏低,为18.21%和31.55%,遗传率为76.27±7.21%。结论前者在碘缺乏环境中呈现出具有主效基因的多基因遗传方式,而后者表现为多基因遗传方式。提示两者的发病都有明显的遗传基础,也说明了试验区的精神发育迟滞具有不同的病因并存在遗传异质性。

Aim To explore the mental retardation （MR） pathogeny in Ningqiang experimental station in Qinba mountain areas, the genetic model was used to study the two types was used to study the mental retardation （MR） pedigree, endemic cretinism or endemic sub-clinical cretinism and non-specific mental retardation （NSMR）. Methods The genetic model analysis was done by segregation analysis and polygenic threshold model. Results The correctional segregation ratio of endemic cretinism or endemic sub-clinical cretinism＇s U x U, U x A mating types are 21.37% and 45.63%,the heritability is 79.00±7.51%. And NSMR＇s correctional segregation ratio of two mating types are very low, 18.21% and 31.55 %. its heritability is 76.27±7.21%. Conclusion The former shows the polygenic inheritance with major gene in iodine deficiency circumstance, and the latter merely shows the polygenic inheritance. The result suggests genetic effect visibly work on both of them, and also shows there are different pathogeny and genetic model in experimental station＇s MR.