Genetic diseases chromosome

Is to determine the sex of the fetus the other Is to determine whether the fetus has a chromosome abnormality Fetal sex determination Is not, at present, performed so that couples can chose the sex of their baby While there may not be any significant ethical or sociological (43) reasons to oppose sex determination for this reason, the lack of sufficient facilities has made this an Indication of extremely low priority The reason for ascertaining the sex of a fetus. In so far as the prenatal diagnosis of genetic disease Is concerned. Is to determine Aether the fetus Is a male or female In situations In which the parents are at risk of having a child with an X-llnked disorder which affects only males If the fetus Is a male. It will have a 50% risk of being affected This risk. In such... 

It is now believed that a substantial proportion of the single nucleotide substitutions causing human genetic disease are due to misincorporation of bases during DNA replication. Which proofreading activity is critical in determining the accuracy of nuclear DNA replication and thus the base substitution mutation rate in human chromosomes ... 

C6PD deficiency is the most common genetic disease in the world, affecting over 400 million people, most of whom are men, because the gene Is located on the X chromosome. 

Artificial chromosomes (Chapter 9) have been constructed as a means of better understanding the functional significance of many structural features of eukaryotic chromosomes. A reasonably stable artificial linear chromosome requires only three components a centromere, telomeres at each end, and sequences that allow the initiation of DNA replication. Yeast artificial chromosomes (YACs see Fig. 9-8) have been developed as a research tool in biotechnology. Similarly, human artificial chromosomes (HACs) are being developed for the treatment of genetic diseases by somatic gene therapy. 

That the feasibility of genetic monitoring of the human population for chromosomal breakage and increased genetic disease be explored. 

Chromosomal aberrations include both numerical and structural aberrations. Numerical aberrations are changes in the number of chromosomes of the normal number characteristic of the animals utilized (aneugenicity). Structural aberrations are classified into two types, chromosome or chromatid aberrations (clastogenicity). Chromosomal mutations and related events are the cause of many human genetic diseases and there is evidence that chromosomal mutations and related events are involved in cancer development. 

---