[The human genome--chromosome 3]

The hitherto little investigated third human chromosome contains genes, the pathogenic alleles of which are responsible for some diseases, in particular retinitis pigmentosa (locus RHO), von Hippel-Lindau syndrome (VHL), epidermolysis bullosa (COL7A1) which is also an example of the situation when different alleles and thus genotypes of the same gene lead to phenotypes which differ so much that they are classified as different diseases. Locuses of the 3rd chromosome participate also in cancerogenesis by the development of the oncogenic genotype as a result of loss of activity or as activated oncogenes. On the third chromosome there is also the locus for alkaptonuria (AKU), a rare metabolic error which is relatively widespread in the north-western part of Slovakia.