Afzelius B A
Am J Hum Genet. 1981 Nov;33(6):852-64.
The immotile-cilia syndrome is a congenital disorder characterized by all cilia in the body being either immotile or showing an ineffective beating pattern. Most symptoms, not unexpectedly, come from the ciliated epithelia, but two further symptoms are: (1) male sterility caused by the spermatozoa being unable to swim progressively (the sperm tail has the same structure as a cilium), and (2) situs inversus in 50% of the cases possible caused by an inability of embryonic cilia to shift the heart to the left side. By electron microscopy, one can see directly which of the many ciliary components is the missing one. The molecular basis of this congenital defect can then be detected, and it has been found to be a heterogeneous disease. There are many genes that, when mutated, will cause the cilia to be dysfunctional or totally immotile. The fact that many genes may be responsible for the syndrome will also explain why it has a relatively high prevalence and why previous investigators have been unable to locate the (assumed single) gene by linkage analysis. The trait, situs inversus, is of particular interest as it occurs in only 50% of the assumed homozygotes. I conclude that the wild-type genes code for a control of the proper body asymmetry and the mutated ones for a lack of control, and, hence, to a random situs determination.
不动纤毛综合征是一种先天性疾病，其特征是体内所有纤毛要么无法运动，要么呈现无效的摆动模式。不出所料，大多数症状源于纤毛上皮，但还有另外两个症状：（1）精子无法进行渐进性游动导致男性不育（精子尾部与纤毛结构相同），以及（2）50%的病例中出现内脏反位，可能是由于胚胎纤毛无法将心脏移至左侧所致。通过电子显微镜，可以直接看到众多纤毛成分中缺失的是哪一种。然后可以检测这种先天性缺陷的分子基础，并且发现它是一种异质性疾病。有许多基因发生突变时会导致纤毛功能失调或完全无法运动。许多基因可能导致该综合征这一事实也将解释为什么它具有相对较高的患病率，以及为什么先前的研究人员无法通过连锁分析定位（假定的单个）基因。内脏反位这一特征特别令人感兴趣，因为它仅在50%的假定纯合子中出现。我的结论是，野生型基因编码对身体正常不对称性的控制，而突变基因则编码缺乏控制，从而导致随机的内脏位置确定。
