Truy cập vào thông tin của nó bị hạn chế và Celera mong đợi quyền sáng chế gen phát sinh từ việc sử dụng dữ liệu của nó. Mặc dù sự kiện quan trọng rất lớn đạt được bởi những dự án giải trình tự hệ gen của con người | Gene mapping and molecular pathology version of the human genome sequence in Science in February 2001 Volume 291 No. 5507 . Access to its information is restricted and Celera expect gene patent rights arising from use of its data. Despite the huge milestone achieved by these human genome sequencing projects the data generated represent only the first step in understanding the way genes work and interact with each other. The human genome sequence needs to be completed and coupled with further research into the molecular pathology of inherited diseases and the development of new treatments for conditions that are at present intractable. Gene localisation Prior to 1980 only a few genes for disorders whose biochemical basis was known had been identified. With the advent of molecular techniques the first step in isolating many genes for human diseases was to locate their chromosomal position by gene mapping studies. In some disorders such as Huntington disease this was achieved by undertaking linkage studies using polymorphic DNA markers in affected families without any prior information about which chromosome carried the gene. In other disorders the likely position of the gene was suggested by identification of a chromosomal rearrangement in an affected individual in whom it was likely that one of the chromosomal break points disrupted the gene. The neurofibromatosis type 1 NF1 gene for example was isolated after the identification of such a translocation followed by cloning and sequencing of DNA from the region of the break point on chromosome 17. In Duchenne muscular dystrophy several affected females had been reported who had one X chromosome disrupted by an X autosome translocation with the normal X chromosome being preferentially inactivated. The site of the break point in these cases was always on the short arm of the X chromosome at Xp21 which suggested that this was the location of the gene for DMD. DNA variations in this region identified by hybridisation with
