Isolation of DNA fragments from chromosome 13

Development of multiple endocrine neoplasia type 2A does not involve substantial deletions of chromosome 10

In MEN2A both familial and sporadic cases are known. The familial cases show a dominant pattern of inheritance. In these respects, MEN2A resembles other tumors in whose etiology so-called tumor suppressor genes play a decisive role. The MEN2A locus has been assigned to chromosome 10 by linkage studies. Analysis of tumor DNA from 42 patients shows that markers on chromosome 10 were lost in only one tumor. Thus, these results contrast with previous studies which show that tumor development is generally associated with the loss of the whole or substantial parts of the chromosome on which the putative tumor suppressor gene is located.

The 35 kd pulmonary surfactant-associated protein is encoded on chromosome 10

The genomic components identified by each of two closely related cDNA clones for the major 35 kilodalton non-serum surfactant-associated proteins (PSP-A) were shown to derive from human chromosome 10 by Southern blot analysis of DNAs from human-rodent somatic cell hybrids. By in situ hybridization to human metaphase chromosomes, the cDNA probes were localized to the region 10q21-q24.

Linkage analysis in a family with dominantly inherited torsion dystonia: exclusion of the pro-opiomelanocortin and glutamic acid decarboxylase genes and other chromosomal regions using DNA polymorphisms

A search for the defective gene causing torsion dystonia has been carried out in a family manifesting an autosomal dominant mode of inheritance of this movement disorder. Complete neurologic examination and establishment of lymphoblast lines have been carried out for over 50 members. Linkage analysis, using cloned DNA sequences and restriction fragment length polymorphisms, was evaluated by the LOD score method with requisite assumptions for mode of inheritance, age-of-onset and incomplete gene penetrance. Genes for pro-opiomelanocortin and glutamic acid decarboxylase, which have been implicated in the etiology of the disease in rat models, were excluded as being responsible for the disease state in this family. Other regions of the genome were also excluded using DNA probes for other genes and random "unique" sequences.

Isolation of human chromosome 13-specific DNA sequences cloned from flow sorted chromosomes and potentially linked to the retinoblastoma locus

A recombinant DNA library has been constructed using flow sorted chromosome #13 DNA and the phage vector, Charon 21A. Roughly 90% of the phage inserts in the library hybridize to human repetitive DNA. Phage containing human nonrepetitive inserts have been screened for chromosome #13 specificity by Southern blot analysis using the genomic DNA of human-rodent cell hybrids containing different regions of the human #13 autosome. Of 18 phage inserts characterized, 13 have been assigned to the 13q12----q22 subregion, three appear to be localized in the 13pter----q12 region, and two are not #13-specific. By Southern blot analysis of the DNA of a retinoblastoma patient exhibiting a deletion of band 13q14 and of karyotypically normal individuals, two phage inserts have been putatively assigned to band 13q14, the currently accepted locus for a genetic determinant for retinoblastoma. These two DNA probes show quantitative differences in hybridization band intensity in the genomic DNA of the 13q--patient relative to that of the normals. In situ hybridization data support these conclusions. A recombinant phage library that shows an approximate 90% enrichment for human chromosome #13-specific DNA fragments should prove useful not only in studies related to retinoblastoma, but also in the molecular analysis of the structure and function of chromosome #13.

Chromosome 13 restriction fragment length polymorphisms

The gene locus for hereditary retinoblastoma is on human chromosome 13, band q14. With this gene localization in mind, we cloned DNA fragments from this chromosome. Three of the fragments identify restriction fragment length polymorphisms. These three fragments are from the region 13q12-13q22, the chromosome region which contains the retinoblastoma locus. We expect that these restriction fragment length polymorphisms will be linked to the retinoblastoma locus, and that they will serve in certain retinoblastoma families as predictors of retinoblastoma gene carriers. They will also be useful in studies of other gene loci thought to be on chromosome 13.