PGM18 in two German families
PGMl-isoenzymes with a mobil i ty slower than a seem to be very rare (Hopkinson and Harris, 1966; Giblett, 1969; Yunis, 1969). Fami ly studies were impossible till now. We observed two not related German families with the allele PGM~ (Fig. 1). The pedigrees are shown in Fig. 2. The compilation of all findings in these families (Table) gives no evidence for linkage. We found these two families within al together 2200 PGMl-investigations. Our observation confirms the suggestion, t ha t PGM~ is a rare allele of the phosphoglueomntase.
Genetics and linkage analysis on phosphoglucomutase
The current study is based on 454 families with 843 children from two different areas in Western Germany (Marburg and Tfibingen). Only families which have been especially ascertained for these investigations have been taken into account. For the estimation of the gene frequencies 1449 unrelated persons from the areas mentioned above were investigated in addition to the parents of the family material. Our technique follows Spencer et al. (1964).
Evidence for a Second ‘Structural’ Locus determining Human Phosphoglucomutase
AT least seven isoenzyme components1 of human phosphoglucomutase (PGM) can be distinguished electrophoretically (a–g, Fig. 1). Individual differences occur in the pattern of components present, and three commonly occurring phenotypes have been recognized (PGM 1, PGM 2–1 and PGM 2). They differ in the distribution of components a, b, c and d. Components a and c are present in PGM 1 and PGM 2–1, while components b and d are present in PGM 2–1 and PGM 2. The genetical evidence indicates that these phenotypic differences are due to a pair of autosomal alleles (PGM1 and PGM2). Evidently a structural locus is involved, and it seems likely that one of these alleles determines the formation of a polypeptide common to a and c, while the other allele determines the formation of an alternative polypeptide common to b and d. The three phenotypes do not differ from one another in the occurrence of components e, f and g. This suggests that at least one other ‘structural’ locus is involved in the determination of these latter components.