journal of Medical Genetics (1970). 7, 367. Protease Inhibitor (Pi) Phenotypes in Chromosome Aberrations

Many enzymes and several enzyme inhibitors are found in multiple molecular forms in different human populations. Some of them constitute im-portant polymorphic systems useful for populations genetics, forensic medicine, and chromosome mapping. However, little is known about the distri-bution ofthese genetic markers in patients with chro-some aberrations and their parents. The purpose ofthe present report is to describe the distribution of Pi types in some families of this type. The Pi system (Fagerhol and Laurell, 1967) com-prises the inherited variants of serum al-antitrypsin. Some of these variants are associated with chronic obstructive pulmonary disease (Laurell and Eriksson, 1963; Fagerhol and Hauge, 1969) and cirrhosis ofthe liver in children (Sharp et al., 1969). The patho-genesis of these conditions is poorly understood. Despite the name of this inhibitor, trypsin is pro-bably not the most important enzyme to be inhibited in vivo. It is more likely that ace-antitrypsin is needed to inhibit intracellular enzymes which may be liberated by tissue damage or inflammation. Proteolytic enzymes are probably active during cell divisions and fertilization. Increased enzyme activity, caused by lack of normal inhibitors, may disturb these events. Subjects and Methods The propositi are 32 children with chromosome aber-rations examined at the Children's Hospital in Bergen. Serum samples were also taken from all available parents. The sera were stored below-20 ° C. until tested. Chromosomal analyses were done by a microtechnique for culturing leucocytes from whole capillary blood. In the XX/XY mosaic cases the mosaic condition was con-firmed in bone-marrow cultures. Pi typing was performed by acid starch gel electro-phoresis (Fagerhol, 1968). Up to now 17 different Pi phenotypes have been ob-served. A schematic drawing of them is presented in the Figure