Hou J W, Wang T R
Department of Pediatrics, National Taiwan University Hospital, Taipei, ROC.
J Formos Med Assoc. 1996 Sep;95(9):686-91.
Fluorescence in situ hybridization (FISH) using chromosome-specific DNA libraries as painting probes, locus-specific unique sequence (cosmid) probes, and Y-specific repetitive sequences was applied in the analysis of eighteen cases of chromosomal rearrangements of undetermined nature. FISH clarified the origin of the extra or translocated chromosome segments in seventeen patients, one with 2q+, two with 4q+, one each with 6p+, 7p+, 9q+, 10p+, 11q+ and 12p+, two with 13q+, and one each with 15q+, 17p+, 18p+, 20p+, 21p+ and Yq+, as well as the nature of a de novo supernumerary chromosome marker in a previously reported case. By G-banding and molecular cytogenetic studies of the family members, six cases were determined to have unbalanced translocations inherited from the carrier parent. The extra translocated genetic material may cause specific trisomic syndromes, including partial 6p21.3-p23, 9q32-q34.3, 13q32-q34, 15q24-q26, and 17p11.2-p13 trisomies in those patients. A translocated 21q segment on 12p was shown by a painting probe in a patient with Down features. A patient with cat cry syndrome resulting from a loss of the terminal segment of the short arm of chromosome 5 was confirmed by a cosmid probe showing de novo reciprocal translocation between chromosomes 5 and 18:t(5;18) (p13.3;p11.31). With FISH, the extra material on the rearranged chromosome could also be identified as duplicated or translocated. The FISH technique thus provides a method for the analysis of extra structurally abnormal chromosomes (especially in de novo cases), recognizable syndromes (contiguous gene syndromes) caused by translocated deletion from parental balanced chromosome rearrangements, and supernumerary marker chromosomes. FISH subsequent to G-banding is also of great help in the confirmation of preliminary abnormal G-banded karyotypes after a modified destaining procedure. In conclusion, the combination of G-banding and FISH is very useful in the accurate diagnosis of chromosomal rearrangements.
使用染色体特异性DNA文库作为涂染探针、基因座特异性单拷贝序列（黏粒）探针以及Y特异性重复序列的荧光原位杂交（FISH）技术，被应用于分析18例性质未明的染色体重排病例。FISH技术明确了17例患者额外或易位染色体片段的来源，其中1例为2q+，2例为4q+，各1例分别为6p+、7p+、9q+、10p+、11q+和12p+，2例为13q+，各1例分别为15q+、17p+、18p+、20p+、21p+和Yq+，同时还明确了1例先前报道病例中一条新生额外染色体标记物的性质。通过对家庭成员进行G显带和分子细胞遗传学研究，确定6例患者具有从携带染色体异常的亲代遗传而来的不平衡易位。额外的易位遗传物质可能导致特定的三体综合征，包括这些患者中的部分6p21.3 - p23、9q32 - q34.3、13q32 - q34、15q24 - q26和17p11.2 - p13三体。在一名具有唐氏特征的患者中，用涂染探针显示12p上有一条易位的21q片段。一名因5号染色体短臂末端片段缺失导致猫叫综合征的患者，通过黏粒探针证实存在5号和18号染色体之间的新生相互易位：t(5;18)(p13.3;p11.31)。通过FISH技术，重排染色体上的额外物质也可被鉴定为重复或易位。因此，FISH技术为分析结构异常的额外染色体（尤其是新生病例）、由亲代平衡染色体重排中的易位缺失引起的可识别综合征（连续基因综合征）以及额外标记染色体提供了一种方法。在经过改良脱色程序后，G显带之后进行FISH对于确认初步异常的G显带核型也有很大帮助。总之，G显带和FISH相结合对于准确诊断染色体重排非常有用。
