Haemoglobinopathies and thalassaemia caused by qualitative and quantitative disorders of the function of the alpha-chain of haemoglobin are associated with chromosome 16 on the short arms of which two of its loci are placed localized mapped. The majority of the human population has four active alpha-chain genes. Reduction of their number to two or less leads to increasing symptoms of their insufficiency manifested as alpha-thalassaemia--complete loss being lethal. On the 16th chromosome is the cause of the dominantly hereditary disease--polycytosis of the kidney so far inaccurately defined at the gene level. The author mentions also the loci of the cholesterylester transfer protein--which participates in the responsibility for hyperlipoproteinaemia and sclerotic changes and loci of haptoglobin chains--one of the serum proteins oldest as regards knowledge of its electrophoretic polymorphism.