[From the information on a structural gene to the disease].
Clinical genetics know more than 4000 hereditary diseases: 7.9% of live born children are born with one of them. For more than 80% of them mutations of structural genes are responsible: either of one or most frequently of several genes. The structural gene is a nucleotide sequence in DNA bearing genetic information for a primary structure of the peptide (protein) chain. A mutation of the structural gene most frequently implies a pathological alteration or loss of biological function of the protein coded by it--which leads to the development of symptoms of disease. Impaired DNA and impaired expression of its information may be caused also by aberration of the chromosome where it is located. Chains of causal relationships between the altered information of the structural gene and the clinical picture of the disease can be followed up in both directions. so far the most frequently used pathway is from a known syndrome to an unknown gene. As an example, we may quote the elucidation of the genetic background of Down's syndrome. Symptoms of Down's syndrome--trisomy of a 21 autochromosome or at least of strip 22 of its q arm in its translocation form--ensue from the abnormally enhanced formation of products of genes located there as a result of an increased gene dose; so far five are known.(ABSTRACT TRUNCATED AT 250 WORDS)
Smarda
J
J
Biologický ústav LF MU, Brno.
D002869:Chromosome Aberrations / Q000235:genetics*; D025063:Chromosome Disorders; D004314:Down Syndrome / Q000235:genetics; D005796:Genes; D006801:Humans; D009154:Mutation; D009369:Neoplasms / Q000235:genetics*; D009857:Oncogenes / Q000235:genetics
Od informace strukturního genu k chorobĕ.