1. Experience with GSH stability test performed on blood samples to which glucose has been added is summarized and the procedure is recommended for routine use for the detection of sensitive subjects.
2. Glutathione stability of erythrocytes has been studied in various population groups of Israel. No case with instable GSH has been found among Jewish subjects originating from Eastern, Central or Western Europe. Instability of GSH was however found in about 20 per cent of subjects originating from Iraq and about 5 per cent of subjects originating from Yemen or North Africa. Isolated cases of this abnormality were also discovered among a small number of persons from other Oriental or Mediterranean countries as well as among the Arab inhabitants of Israel.
3. The genetic analysis points to a transmission of glutathione instability by a sex-linked, incompletely dominant gene with variable expressivity.
4. Variable expressivity of glucose-6-phosphate dehydrogenase activity has also been detected in the defective erythrocytes.