Linkage and association studies of two phosphoglucomutase loci (PGM1 and PGM3) to eighteen other markers. Analysis of the segregation at the marker loci

Gene localisation of the PGM1 enzyme system and the Duffy blood groups on chromosome No. 1 by means of a new fragile site at 1p31

During routine paternity testing an apparent maternal exclusion was suggested by the PGM1 enzyme system (mother PGM1 1, child PGM1 2) and by the Duffy system (mother Fy(a-b+), child Fy(a+b-]. To clarify these findings chromosomal analyses and anthropological investigations were carried out. The possibility that the child had been mistakenly identified after birth could be eliminated. Chromosome analysis of the child showed a fragile site on one chromosome No. 1 at 1p31, a position supposed to carry the PGM1 and the Duffy loci. Although the father of the child is unknown, paternal origin of the fragile site is unlikely on account of the coincidence of the structural aberration with the missing expression of the maternal PGM1 and Duffy alleles thought to be located at the chromosome region involved. Thus localisation of the PGM1 and Duffy loci on 1p31 seems to have been achieved in an unusual way. The two loci appear to be closely linked.

Mapping of the linkage group GLO--Bf--HLA-B,C,A--PGM3. 2. Segregation analysis

Segregation analysis of informative families for chromosome 6 markers confirmed the map order GLO--Bf--HLA-(B, C)--HLA-A, and, surprisingly, implies that PGM3 is more probably located on the HLA-A than on the HLA-B side of the linkage group. Therefore the map position of PGM3 should be reconsidered, i.e., more informative families should be tested for all the relevant marker loci available.

PGM3 locus and its genetic polymorphism in lymphocytes of the pig

PGM3 activity was investigated by means of horizontal starch gel electrophoresis. In the pig of the German Landrace three different phenotypes have been recognized: F, S and FS. Family studies suggest the occurrence of at least two alleles--PGM3F and the PGM3S at an autosomal locus.

Map order of the linkage group GLO-Bf-HLA-A-PGM3 on human chromosome 6

Linkage analysis of 52 families with 181 children confirms close linkage for GLO-Bf, GLO-HLA-A, and Bf-HLA-A and proves linkage between HLA-A and PGM3. Linkage for Bf-PGM3 and GLO-PGM3, respectively, seems to be likely; close linkage can be excluded. From the relative map distances, but above all from the segregation of defined linkage phases in crossover families, we can hypothesize that the sequence order of the loci should be GLO-Bf-HLA-A-PGM3.

Possible linkage of HL-A and GLO

In 21 informative families with 60 children, a possible linkage between HL-A and GLO was found (recombination fraction approximatively 0.15). The sequence of the loci on chromosome 6 might be GLO, HL-A, PGM3, MNSs.

[Relation between the Rhesus and Gm systems, their localization on chromosome]

The accumulated combination (X2 = 11.28 greater than 9.21) of Gm 1+ with Rh(CC) and of Gm 1-with Rh(cc) demonstrates the synteny of both markers on chromosome 1.

Phosphoglucomutase 3: formal and population genetics and observations on abnormal phenotypes

514 healthy blood donors and 47 families with 122 offspring were studied for phosphoglucomutase 3 (PGM3) from leukocytes. There was a good agreement of allelic frequencies obtained compared to those reported previously in Caucasians. In addition, three individuals with abnormal phenotypes were observed: one was a patient with Hodgkin's disease, the other two were apparently healthy blood donors. In two cases, family members could be studied; none carried the abnormal type of the father. The possible background of these observations with respect to the attachment of the PGM3 locus to the immunogenetic linkage group--the major histocompatibility complex--on chromosome No. 6 in man is discussed.

Confirmation of the linkage HL-A/PGM3

In a series of 42 families with 101 children the linkage between HL-A and PGM3 could be confirmed (most likely recombination fraction for male equals 0.15).

Data on the HL-A linkage group

Lod scores from a study in 229 families of the linkage relations of HL-A-PGM3 to 19 marker loci and cystic fibrosis are reported. The data exclude that ADA belongs to this linkage group while they give weak support for the inclusion of P. There is weak evidence for linkage of cystic fibrosis to PGM3, but none for linkage to HL-A. No new suggestive linkages appeared.

Somatic cell genetic assignment of peptidase C and the Rh linkage group to chromosome A-1 in man

The segregation of the human peptidase-C phenotype in five different series of human-mouse hybrid clones was examined. The chromosome constitution of these hybrids was determined by quinacrine mustard fluorescence, Giemsa banding, and constitutive heterochromatin staining. That the clones could be classified without exception either as human peptidase C positive/ A-1 positive (14 clones), or as peptidase C negative/ A-1 negative (12 clones) indicates that peptidase C can be assigned to the human A-i chromosome. Data from an extensive series of human-mouse clones used provide support for the syntenic association between peptidase C and phosphoglucomutase-1 and by inference a linkage of both to Rh factor group.