Pihko H, Therman E, Uchida I A
Hum Genet. 1981;58(2):129-34. doi: 10.1007/BF00278696.
The syndrome caused by partial trisomy for 11q is reviewed on the basis of a patient of our own and 20 cases (including a stillbirth) from the literature. The main symptoms are presented in Tables 1 and 2. The syndrome can be suspected when, in addition to mental retardation, the following characteristics are present: short nose, long philtrum, micrognathia, retracted lower lip, and micropenis in males. In 15 families, the mother was a balanced translocation carrier and in four the father. The translocation had arisen de novo in two patients. The chromosome number was 46 in 13 affected individuals (including the stillbirth) and 47 in eight. In seven of the latter patients the other translocation chromosome was 22, and in one, chromosome 9. The breakpoints on 11q ranged from 11q121 to 11q232 (Fig. 5). There is no apparent correlation between the length of the trisomic segment and the number or severity of the symptoms (Table 2). This could be explained by assuming that most, if not all, symptoms are caused by trisomy for the Q-dark region distal to 11q232, whereas trisomy for the rest of the 11q up to q121 has few phenotypic effects. These observations support the idea that Q-dark segments, and especially certain hot spots, have a high gene density in contrast with Q-brighter regions.
基于我们自己的一名患者以及文献中的20例病例（包括1例死产），对由11号染色体长臂部分三体引起的综合征进行了综述。主要症状列于表1和表2。当除智力迟钝外还出现以下特征时，可怀疑患有该综合征：短鼻、长人中、小颌、下唇回缩以及男性小阴茎。在15个家庭中，母亲是平衡易位携带者，4个家庭中父亲是携带者。有2例患者的易位是新发的。13名受影响个体（包括死产）的染色体数目为46条，8名个体为47条。在后者中的7例患者中，另一条易位染色体是22号，1例是9号染色体。11号染色体长臂上的断点范围从11q121至11q232（图5）。三体片段的长度与症状的数量或严重程度之间没有明显关联（表2）。这可以通过假设来解释，即大多数（如果不是全部）症状是由11q232远端的Q暗区三体引起的，而11号染色体长臂直至q121的其余部分三体对表型影响很小。这些观察结果支持了这样一种观点，即与Q亮区相比，Q暗区，尤其是某些热点，具有较高的基因密度。
