Assignment of the peptidase D gene locus (PEPD) to chromosome 19 in man

The human chromosome 19 linkage group FUT1 (H), FUT2 (SE), LE, LU, PEPD, C3, APOC2, D19S7 and D19S9

Families segregating for deficiency of the H alpha-2-L-fucosyltransferase, FUT1, have been investigated for linkage between FUT1 and other markers on chromosome 19. The results provide evidence for close linkage between FUT1 and FUT2 and for looser linkage between FUT1 and APOC2 and between FUT1 and D19S7. Pairwise linkage data are also reported between other markers investigated.

Localization of PEPD to the long arm of chromosome 19

A panel of human-rodent somatic cell hybrids containing different regions of chromosome 19 has been used to obtain a regional localization for peptidase D. The results assign PEPD to the long arm of chromosome 19, in the region cen-q13.2

A genetic map of chromosome 19 based on family linkage data

A large linkage group has been assigned to chromosome 19. The loci have been ordered using a two-point mapping analysis based on all available family linkage data summarized in the form of lod score tables.

Linkage relationships of the gene for apolipoprotein CII with loci on chromosome 19

Two common restriction fragment length polymorphisms detected with cloned gene probes for apolipoprotein CII (apo CII) have been used to study the inheritance of the gene in families segregating for loci on chromosome 19. Lod scores for APOC2 with the gene for complement component 3 (C3) exclude close linkage and give a maximum at a male recombination fraction of 0.25-0.30. Lod scores for APOC2 and FHC, the gene causing familial hypercholesterolaemia, are negative in males and suggest the genes may not be linked. However, it appears that APOC2 may be closely linked to the blood group loci Lutheran (Lu) and Secretor (Se), and probably less closely linked to Lewis (Le). These data are consistent with the gene order: FHC-----C3-----(Lu, Se, APOC2)

Localisation of genetic markers and orientation of the linkage group on chromosome 19

A panel of human-rodent somatic cell hybrids containing translocation derivatives of human chromosome 19 has been used to assign the markers peptidase D, complement component 3, lysosomal mannosidase, lysosomal DNAase, chorionic gonadotropin beta-subunit, and a new polymorphic DNA sequence, to specific regions of chromosome 19. This has allowed the relative orientations of the genetic and physical maps to be established, and provides the framework for a search for the genes responsible for inherited disorders on chromosome 19, such as myotonic dystrophy and neurofibromatosis.

The locus for apolipoprotein E (apoE) is close to the Lutheran (Lu) blood group locus on chromosome 19

Linkage has been described between the loci for apolipoprotein E (apoE) and the complement C3 (C3) on chromosome 19. C3 is known to belong to a linkage group with gene order C3-Se-Lu. The present study revealed linkage between Se and apoE with peak lod score +3.3 at recombination fraction 0.08 in males and +1.36 at 0.22 in females, and linkage between apoE and Lu with lod score +4.52 at zero recombination in sexes combined. The C3-apoE linkage gives lod score +4.00 at theta = 0.18 in males, but +0.04 at theta = 0.45 in females. Triple heterozygote families confirm that apoE is on the Se side and on the Lu side of C3. Allelic association between apoE and Lu has not been ruled out. Combining our data with published data on C3-Se and Se-Lu, this segment of chromosome 19 has an average age sex ratio of female/male recombination of 2.3.

Prolidase and prolidase deficiency

Prolidase deficiency seems to be a rather rare metabolic disorder. However, many new cases can be detected because screening is easy to perform and enzymatic confirmation allows the differentiation from other iminodipeptidurias . Clinical symptoms are briefly reviewed, while biological considerations and prolidase properties are exhaustively described. Methods for investigating urinary iminodipeptides are given with results. Moreover, several collagen modifications observed in this disorder led us to formulate a hypothesis for their mechanism. Genetic considerations and treatment attempts are discussed.

Genetics and linkage relationships of the C3 polymorphism: discovery of C3-Se linkage and assignment of LES-C3-DM-Se-PEPD-Lu synteny to chromosome 19

The C3 complement system was examined in our Danish material of normal families, which had earlier been examined for 59 marker systems, and in a myotonic dystrophy family material. A total of 8 alleles were recognized, with allele frequencies as follows: C3*S = 0.7902, C3*F = 0.2018, C3*S rare (3 lumped together) = 0.0036, C3*F rare (2 lumped together) = 0.0024; a silent allele was recognized in three families and its frequency estimated to C3*QO = 0.002. The distribution of unrelated individuals did not deviate significantly from the Hardy-Weinberg expectation, it was not significantly different between the sexes, and for none of the mating types was there any significant deviation from the expected ratios of children. As to linkage relationships of C3 with marker systems and with myotonic dystrophy, there was evidence (most of it first presented at the 6th International Congress of Human Genetics, Jerusalem 1981) for synteny with ABH secretion (Se): C3-Se (males) z = 4.35, theta = 0.12 and with Lewis secretion (LES): C3-LES (males z = 3.63, theta = 0.04). There were indicative or suggestive lod scores for Se-PEPD (males & females z = 2.41, theta = 0.00), C3-Lu (z = 1.88, theta = 0.15), C3-DM (z = 1.69, theta = 0.06) and PEPD-C3 (male z = 0.95, theta = 0.17). The most likely sequence of these 6 systems would appear to be LES-C3-DM-(Se-PEPD)-Lu and the synteny would reside on chromosome 19.

Genetic linkage between the loci for myotonic dystrophy and peptidase D

In a linkage study between myotonic dystrophy and peptidase D it is evident from the lod score values that with high probability theta lies between 0 and 0.1. The data thus support a previous hint of linkage between peptidase D and the Lutheran and secretor loci, which were already known to be linked to myotonic dystrophy.

Genetic variation for prolidase (PEP-4) in the mouse maps near the gene for glucosephosphate isomerase (GPI-1) on chromosome 7

An inherited electrophoretic variant of prolidase (EC 3.4.13.9), also called peptidase 4 (PEP-4), has been discovered among inbred strains of mice. Analysis of progeny from reciprocal backcrosses established that the electrophoretic forms are expressed codominantly and that Pep-4 is located between the genes for glucosephosphate isomerase (Gpi-1) and pink-eyed dilution (p) on chromosome 7. These data define a region of conserved gene linkage between mouse chromosome 7 and human chromosome 19, as originally indicated by somatic cell hybrid studies, and imply that human prolidase (PEPD) is located in the region of human chromosome 19 pter greater than q13.

Assignment of peptidase S (PEPS) to chromosome 4 in man using somatic cell hybrids

A starch gel electrophoretic procedure is described that resolves peptidase S (PEPS) as well as the peptidases A, B, and C in man-rodent, rodent-rodent, and primate-rodent interspecific somatic cell hybrids. The interspecific PEPS cell hybrid phenotype can be resolved into a pattern which suggests that PEPS is composed of five or six identical subunits. Results are presented supporting assignment of the PEPS locus to chromosome 4 in man using man-mouse and man-Chinese hamster somatic cell hybrids. Human genes coding for peptidases A, B, C, and D were assigned to chromosome 18, 12, 1, and 19, respectively, confirming previous assignments. These somatic cell genetic data demonstrate the independent genetic control of the several human peptidases.