PURPOSE: To describe the ocular features of a patient with an interstitial deletion of chromosome 12 and to determine the molecular boundaries of the deletion. DESIGN: Observational case report and laboratory investig...PURPOSE: To describe the ocular features of a patient with an interstitial deletion of chromosome 12 and to determine the molecular boundaries of the deletion. DESIGN: Observational case report and laboratory investigation. METHODS: A patient with an interstitial deletion of chromosome 12 was clinically examined for ocular abnormalities. DNA samples were used for molecular studies to define the deletion boundaries. RESULTS: Ocular examination showed abnormalities of the anterior segment consistent with a diagnosis of cornea plana. Molecular analyses showed the deletion included the KERA gene,the SLRP (small leucine repeat protein) gene cluster,the genetic loci for autosomal-dominant (CNA1) and autosomalrecessive (CNA2) cornea plana,and a portion of the mapped locus for high myopia (MYP3). CONCLUSIONS: These results,combined with previous genetic linkage studies,identifies a 3-cM region located between microsatellite markers D12S82 and D12S351 that is likely to contain a gene responsible for CNA1.展开更多
Allelic loss of chromosome 4q is one of the most frequent genetic aberrations found in human hepatocellular carcinoma (HCC) and suggests the presence of putat ive tumor suppressor genes within this region. To precisel...Allelic loss of chromosome 4q is one of the most frequent genetic aberrations found in human hepatocellular carcinoma (HCC) and suggests the presence of putat ive tumor suppressor genes within this region. To precisely define the region co ntaining these tumor suppressor genes for further positional cloning, we tried a detailed deletion mapping strategy in 149 HCCs by using 49 microsatellite marke rs covering 4q12≈25. A common region with allelic loss has been identified base d on the interstitial deletions occurring within it; this region is found betwee n D4S1534 and D4S1572 (a 17.5-cM genetic interval). When we included all cases with limited aberration regions for comparison, 2 smaller regions were derived: 1 between D4S1534 and D4S2460 (3.52 cM) and 1 between D4S2433 and D4S1572 (8.44 cM). A few candidate genes were found to be down-regulated in HCCs, but without sequence mutations. In these HCCs, 4q alleleic loss was associated with hepatit is B virus infection status and the elevation of serum alpha-fetoprotein (≥400 ng/mL). In conclusion, the current study not only mapped a common allelic loss region on chromosome 4q, but it also revealed that its loss may be involved in h epatitis B virus-related hepatocarcinogenesis and the elevation of serum alpha -fetoprotein.展开更多
OBJECTIVE: To determine the karyotype of a cryptic structural abnormality and explore the mechanism of apparent chromosomal terminal deletion. METHODS: Fluorescence in situ hybridization(FISH) with a whole chromosome ...OBJECTIVE: To determine the karyotype of a cryptic structural abnormality and explore the mechanism of apparent chromosomal terminal deletion. METHODS: Fluorescence in situ hybridization(FISH) with a whole chromosome 7 painting probe and a 7q subterminal probe (7q36-->qter), prepared by chromosome microdissection technique, was used to analyze a case with a history of spontaneous abortion and 7q terminal deletion detected by conventional G-banding technique. RESULTS: The case was a maternal cryptic insertional translocation between chromosome region 1p32 and 7q32-->q35. The region of chromosome 7q36-->qter was not inserted in to chromosome 1, and the abnormal chromosome 7 was not a terminal deletion but an interstitial deletion. CONCLUSIONS: Chromosome insertion of the terminal region retains its telomere, which is consistent with the concept of a three-break rearrangement. Interstitial deletion may be regarded as another mechanism for terminal deletion in the chromosome banding level. Combined with chromosome microdissection, FISH technique could be a powerful diagnostic tool for detecting chromosome structural abnormalities.展开更多
文摘PURPOSE: To describe the ocular features of a patient with an interstitial deletion of chromosome 12 and to determine the molecular boundaries of the deletion. DESIGN: Observational case report and laboratory investigation. METHODS: A patient with an interstitial deletion of chromosome 12 was clinically examined for ocular abnormalities. DNA samples were used for molecular studies to define the deletion boundaries. RESULTS: Ocular examination showed abnormalities of the anterior segment consistent with a diagnosis of cornea plana. Molecular analyses showed the deletion included the KERA gene,the SLRP (small leucine repeat protein) gene cluster,the genetic loci for autosomal-dominant (CNA1) and autosomalrecessive (CNA2) cornea plana,and a portion of the mapped locus for high myopia (MYP3). CONCLUSIONS: These results,combined with previous genetic linkage studies,identifies a 3-cM region located between microsatellite markers D12S82 and D12S351 that is likely to contain a gene responsible for CNA1.
文摘Allelic loss of chromosome 4q is one of the most frequent genetic aberrations found in human hepatocellular carcinoma (HCC) and suggests the presence of putat ive tumor suppressor genes within this region. To precisely define the region co ntaining these tumor suppressor genes for further positional cloning, we tried a detailed deletion mapping strategy in 149 HCCs by using 49 microsatellite marke rs covering 4q12≈25. A common region with allelic loss has been identified base d on the interstitial deletions occurring within it; this region is found betwee n D4S1534 and D4S1572 (a 17.5-cM genetic interval). When we included all cases with limited aberration regions for comparison, 2 smaller regions were derived: 1 between D4S1534 and D4S2460 (3.52 cM) and 1 between D4S2433 and D4S1572 (8.44 cM). A few candidate genes were found to be down-regulated in HCCs, but without sequence mutations. In these HCCs, 4q alleleic loss was associated with hepatit is B virus infection status and the elevation of serum alpha-fetoprotein (≥400 ng/mL). In conclusion, the current study not only mapped a common allelic loss region on chromosome 4q, but it also revealed that its loss may be involved in h epatitis B virus-related hepatocarcinogenesis and the elevation of serum alpha -fetoprotein.
文摘OBJECTIVE: To determine the karyotype of a cryptic structural abnormality and explore the mechanism of apparent chromosomal terminal deletion. METHODS: Fluorescence in situ hybridization(FISH) with a whole chromosome 7 painting probe and a 7q subterminal probe (7q36-->qter), prepared by chromosome microdissection technique, was used to analyze a case with a history of spontaneous abortion and 7q terminal deletion detected by conventional G-banding technique. RESULTS: The case was a maternal cryptic insertional translocation between chromosome region 1p32 and 7q32-->q35. The region of chromosome 7q36-->qter was not inserted in to chromosome 1, and the abnormal chromosome 7 was not a terminal deletion but an interstitial deletion. CONCLUSIONS: Chromosome insertion of the terminal region retains its telomere, which is consistent with the concept of a three-break rearrangement. Interstitial deletion may be regarded as another mechanism for terminal deletion in the chromosome banding level. Combined with chromosome microdissection, FISH technique could be a powerful diagnostic tool for detecting chromosome structural abnormalities.
