GENE LINKAGE STUDY OF IMMUNODEFICIENCY IN NAVAJO INDIANS

重症联合免疫缺陷病是一种常染色体隐性遗传 在说阿萨巴斯卡语的印度人(纳瓦霍人和阿帕奇人)中发生的突变 频率约为2%。纳瓦霍族SCID的发病率 婴儿是1：2000的活产儿。这项研究的具体目的是绘制 利用遗传连锁的方法寻找“纳瓦霍SCID”隐性基因 SCID基因与已知染色体DNA标记的共遗传 地点。为了实现这一点，我们将使用高度 包括CA重复微卫星标记在内的多态DNA标记 在整个人类基因组中。到目前为止，我们有200多个DNA标记， 包括80多个可变数目串联重复序列(VNTR)和125个CA重复序列 微卫星标记。为了研究继承，我们组装了一个 收集了16个不同的纳瓦霍血统的DNA制剂。这 包括17名受影响的儿童和总共78名家庭成员。这个 受影响的样本人口正在以大约每两个亲属的速度增长 年。DNA样本将使用DNA探针和 微卫星标记。这些数据将被分析以找到联系 在作图的探针和SCID基因之间。我们计划使用联动装置 对患病胎儿和携带者进行产前诊断的信息 检测未受影响的亲属。最终，我们计划确定和 描述导致这位美洲原住民SCID的基因 并了解其在调节免疫功能中的作用。

Severe Combined Immunodeficiency Disease (SCID) is an autosomal recessive mutation that occurs in Athabascan speaking Indians (Navajo and Apache) at a frequency of approximately 2%. The incidence of SCID in Navajo babies is 1:2000 live births. The specific aim of this study is to map the "Navajo SCID" recessive gene by using genetic linkage, looking for coinheritance of the SCID gene with a DNA marker of known chromosomal location. To accomplish this, we will use a collection of highly polymorphic DNA markers including CA repeat microsatellite markers throughout the human genome. To date, we have over 200 DNA markers, including 80+ variable number tandem repeats (VNTR) and 125 CA repeat microsatellite marker. To study inheritance, we have assembled a collection of DNA preparations from 16 different Navajo kindreds. This includes 17 affected children and a total of 78 family members. The affected sample population is growing at approximately two kindreds per year. The DNA samples will be typed using the DNA probes and microsatellite markers. These data will be analyzed to find linkage between a mapped probe and the SCID gene. We plan to use the linkage information for prenatal diagnosis of affected fetuses and carrier detection of unaffected relatives. Eventually, we plan to identify and characterize the gene which causes SCID in this native American population and understand its role in regulating immune function.