A new biallelic DNA polymorphism of the human COL5A1 gene

A cDNA probe of the human COL5A1 gene detects a frequent biallelic PstI polymorphism. Allele A has a frequency of 54% whereas that of allele B is 46%. This restriction fragment length polymorphism provides a useful marker for linkage analysis in 9q34.3.     

COL1A2 gene deletion polymorphism in an Italian and an Ivorian populations

The COL1A2 gene is one of the two genes encoding for the polypeptides of type I collagen, that represent the major constituent of skin, bone, tendons, ligaments, blood vessels, dentin, and many interstitial tissues. The COL1A2 gene deletion polymorphism has been considered as an informative anthropological marker for describing geographically distinct human populations. Aim of the present study was to investigate the genetic variability at COL1A2 locus in two populations, one belonging to Ouangolodougou (n = 133), a village placed in Northern Ivory Coast, and one belonging to Lecco (n = 70), a village placed in a Northern Italy region called Lombardy. For each sampled population no data are available in literature. We reported, for the first time, the presence of the deleted allele among Ivorians (0.06), confirming the low deletion frequency of this polymorphism found in Sub Saharan Africa by other authors. For Italians, frequency analysis of this gene polymorphism (0.28 for the deleted allele) did not show any significant level of differentiation with respect to other Italian and European populations. The article is published in the original.     

Mild spondyloepiphyseal dysplasia (Namaqualand type): genetic linkage to the type II collagen gene COL2A1.

Namaqualand spondyloepiphyseal dysplasia (NSED) is a mild autosomal dominant form of spondyloepiphyseal dysplasia in which changes are maximal in the femoral capital epiphyses and the vertebral bodies. The condition is present in a large multigeneration South African family, and it is clinically important by virtue of severe progressive degenerative osteoarthropathy of the hip joint, which frequently necessitates prosthetic joint replacement in adulthood. Linkage studies using molecular markers have shown that the loci for the NSED and type II collagen genes are linked (LOD score 7.98 at a recombination fraction of .00).     

Mapping of the human COL5A1 gene to chromosome 9q34.3

Summary A 353-bp region encoding for the NH₂ terminus of the noncollagenic part of the l(V) chain was amplified by the polymerase chain reaction (PCR), subcloned and sequenced. The subcloned PCR product (pGC1) presented the same nucleotide sequence as the original fragment from the published sequence of COL5A1. In situ hybridization, using pGC1 as a probe, mapped the COL5A1 gene to chromosome 9q34.3. This assignement shows that COL5A1 is not synthenic with COL5A2, which is localized together with other collagen genes on chromosome 2.     

Identification of COL6A1 as a differentially expressed gene in human astrocytomas

Diffuse infiltrating gliomas are the most common tumors of the central nervous system. Gliomas are classified by the WHO according to their histopathological and clinical characteristics into four classes: grade I (pilocytic astrocytoma), grade II (diffuse astrocytoma), grade III (anaplastic astrocytoma), and grade IV (glioblastoma multiforme). Several genes have already been correlated with astrocytomas, but many others are yet to be uncovered. By analyzing the public SAGE data from 21 patients, comprising low malignant grade astrocytomas and glioblastomas, we found COL6A1 to be differentially expressed, confirming this finding by real time RT-PCR in 66 surgical samples. To the best of our knowledge, COL6A1 has never been described in gliomas. The expression of this gene has significantly different means when normal glia is compared with low-grade astrocytomas (grades I and II) and high-grade astrocytomas (grades III and IV), with a tendency to be greater in higher grade samples, thus rendering it a powerful tumor marker.