Genetic mapping of the pericentric region of human chromosome 10
A genetic linkage map of the pericentric region of human chromosome 10 has been generated to better define the region containing the gene causing the multiple endocrine neoplasia type 2A (MEN-2A) disease, earlier limited to a 15.1 cM interval. 6 new markers have been added to this interval, where the markers are separated by an average of 2.65 cM. These new markers were used to evaluate three large MEN-3A families and did not reveal any recombinants that could better define the MEN-2A containing region. These families were used, however, to determine risks for individuals who were potential gene carriers. Six individuals were determined to be gene carriers and one individual, who had a thyroidectomy based on clinical testing results, was determined not to be a gene carrier. These results suggest that conventional clinical criteria need to be altered to include results from genetic testing. Since the map was generated, the RET proto-oncogene has been identified as the MEN-2A disease gene. The markers have been used to analyze familial and sporadic medullary thryoid carcinomas (MTCs). This analysis has determined one tumor (NL5) has retained heterozygosity for a limited region encompassing the RET region but has lost heterozygosity at all flanking loci on chromosome 10 tested, losing the allele which segregated with MEN-2A, suggesting a chromosomal rearrangement involving the RET locus. An analysis of sporadic and familial allelic instability with several dinucleotide repeat markers from chromosome 10 as well as other chromosomes. Similar results have been observed in colorectal cancer involving mutation in a mismatch repair enzyme (hMSH2). It is difficult to envision a direct role for the RET proto-oncogene in genetic instability, as seen in the colorectal tumors. Consequently, the genetic instability seen in the MEN-2A tumors, perhaps caused by mutations in the hMSH2 gene, may be the result of secondary effects developing independently from RET in MEN-2A tumors.
- Research Organization:
- Wake Forest Univ., Winston-Salem, NC (United States)
- OSTI ID:
- 39162
- Resource Relation:
- Other Information: TH: Thesis (Ph.D.); PBD: 1994
- Country of Publication:
- United States
- Language:
- English
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