https://scholars.lib.ntu.edu.tw/handle/123456789/188418
Title: | 國人血脂異常相關之基因研究─台灣族群血脂蛋白(a)之遺傳學研究 | Other Titles: | Molecular genetic of apolipopr otein (a) in Taiwan | Authors: | 李啟明 | Keywords: | lipoprotein(a);apo(a);polymorphism;coronary atherosclerosis | Issue Date: | 1999 | Publisher: | 臺北市:國立臺灣大學醫學院內科 | Abstract: | High plasma level of Lp(a) (>25~30 mg/dl) is one of the major risk factors for coronart atherosclerosis and its major complication, but is different from LDL by the large glycoprotein named apolipoprotein(a) (apo(a)). The kringle IV domain of apo(a) is variously repeated form about 15 to 40 times in individual, resulting in a large number of molecular weight isoforms of the protein. The significance of Lp(a) on coronary heart disease (CHD) and the genetic bases for the variation in plasma Lp(a) concentration for population in Taiwan are, however, not understood. In a prospective Chin-Shan Community Cardiovascular (CCC) study, the Lp(a) plasma level showed a skew distribution (mean 14.3 mg/dl, medium 9.0 mg/dl, n=3453). A hospital-based study in National Taiwan University Hospital (NTUH) disclosed higher Lp(a) levels in patients with than those without significant coronary lesions (33.0 ± 21.9 versus 23.6 ± 17.6 mg/dl, n = 381, P<0.0001). Sixteen isoforms of apo(a) have been identified based on electromobility, including 5 F-forms, 1 B-form, 9 S-forms and a null form. Seventy four percent of the subjects have two bands, 23.1 % have single band and 2.6 % are null type, and six cases of them contain both S-and F-forms. Subjects containing F- or null form have high Lp(a) level than subjects containing S-form (45.6 ± 19.5 versus 21.5 ± 13.1 mg/dl, p<0.0001). Subjects containing larger apo(a) isoforms (S5-S9) have lower risk of CAD than those having smaller isoforms (S1-S4) (0.51, n = 164 versus 0.68, n = 93; p<0.01). For subjects (n = 47) with plasma Lp(a) level disproportion to its apo(a) size, the TTTTA-repeats in the 5'-control region of the apo(a) gene was analyzed by polymerase chain reaction and nucleotide sequencing. The majority have 7 (8.5%), 8 (42.5%), or 9 (42.5%) repeats. Only 1 case (2.1%) for 4, 5, and 6 repeats, individually. There is no significant correlation between the number of TTTTA repeats and plasma Lp(a) concentration. We conclude that the apo(a) size polymorphism, but not TTTTA repeats in the 5’ control region, significantly correlated with the plasma Lp(a) level, which in turn correlated with the prevalence of CAD in our study group. These results would be helpful in the prevention and treatment of CAD in Taiwan. |
URI: | http://ntur.lib.ntu.edu.tw//handle/246246/29762 | Other Identifiers: | 882314B002089M40 | Rights: | 國立臺灣大學醫學院內科 |
Appears in Collections: | 醫學系 |
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882314B002089M40.pdf | 48.51 kB | Adobe PDF | View/Open |
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