Earle E, Dale S, Choo K H
Murdoch Institute for Research into Birth Defects, Royal Children's Hospital, Melbourne, Australia.
Hum Genet. 1989 May;82(2):187-90. doi: 10.1007/BF00284055.
A phenotypically normal male (WSm) was found to have an unusually large short arm of chromosome 14. Increase in the size of this variant chromosome [Wsm-var(14)] was estimated to be approximately 30% that of a normal chromosome 14 by G-banding using trypsin and staining with Leishman. The extra chromosomal material was positive in CBG staining (C-banding using BaOH and staining with Giemsa), suggesting the presence of repetitive DNA. In situ hybridisation using repetitive probes demonstrated this material to be strongly positive for satellite III DNA, and negative for Y-specific heterochromatic DNA. Hybridisation with an alpha DNA probe specific for human acrocentric chromosomes indicated the retention of the centromere, and the absence of alpha DNA in the extra chromosomal material. We propose the origin of the extra chromosomal material in WSm-var(14) to be a result of amplification of contiguous satellite III DNA that is normally present in the short arm of chromosome 14. This variant chromosome does not appear to be associated with the abnormal phenotype in WSm's daughter who is mentally retarded and carries a t(1;?)(q41;?) translocation of chromosome 1.
发现一名表型正常的男性（WSm）的14号染色体短臂异常大。通过使用胰蛋白酶进行G显带和利什曼染色，估计这条变异染色体[Wsm-var(14)]的大小约为正常14号染色体的30%。额外的染色体物质在CBG染色（使用氢氧化钡进行C显带和吉姆萨染色）中呈阳性，表明存在重复DNA。使用重复探针进行原位杂交显示，该物质对卫星III DNA呈强阳性，对Y特异性异染色质DNA呈阴性。用针对人类近端着丝粒染色体的α DNA探针进行杂交表明，着丝粒得以保留，额外的染色体物质中不存在α DNA。我们认为WSm-var(14)中额外染色体物质的起源是14号染色体短臂中正常存在的连续卫星III DNA扩增的结果。这条变异染色体似乎与WSm智力发育迟缓的女儿的异常表型无关，其女儿携带1号染色体的t(1;?)(q41;?)易位。
