Heritability of LPA allele, apo(a) isoform sizes, and isoform-associated lipoprotein(a) [Lp(a)] levels was studied in 82 Caucasian and African-American families with two parents and two children (age: 6-74 years). We determined: 1) Lp(a) levels; 2) LPA allele sizes; 3) apo(a) isoform sizes; and 4) isoform-specific apo(a) levels (ISLs), the amount of Lp(a) carried by an individual apo(a) isoform. Trait heritability was estimated by mid-parent-offspring analysis. The ethnicity-adjusted heritability estimate for Lp(a) level was 0.95. Heritability for ISLs corresponding to the smaller LPA allele in a given allele-pair was higher than that corresponding to the larger LPA allele (0.91 vs. 0.59, P = 0.017). Although not statistically different, heritability for both apo(a) isoforms (0.90 vs. 0.70) and LPA alleles (0.98 vs. 0.82) was higher for the smaller versus larger sizes. Heritability was generally lower in African-Americans versus Caucasians with a 4-fold difference for the larger LPA allele (0.25 vs. 0.94, P = 0.001). In Caucasians, an overall higher heritability pattern was noted for the older (≥47 years) versus younger (<47 years) families. In conclusion, Lp(a) level and traits associated with the smaller LPA alleles were strongly determined by genetics, although with a varying ethnic influence. Ethnic differences in heritability of the larger LPA allele warrant further investigations.

中文翻译：

---

两代非洲裔美国人和白人家庭中载脂蛋白 (a) 性状的遗传力。

在 82 个有两个父母和两个孩子（年龄：6-74 岁）的白人和非裔美国人家庭中，研究了 LPA 等位基因、apo(a) 同工型大小和同工型相关脂蛋白 (a) [Lp(a)] 水平的遗传性）。我们确定：1 ) Lp(a) 水平；2）LPA等位基因大小；3 ) apo(a) 同工型大小；4 )同工型特异性apo(a)水平(ISL)，即单个apo(a)同工型携带的Lp(a)的量。通过中亲子代分析估计性状遗传力。Lp(a) 水平的种族调整遗传力估计值为 0.95。较小LPA对应的 ISL 的遗传力给定等位基因对中的等位基因高于对应于较大LPA等位基因的等位基因（0.91 vs. 0.59，P = 0.017）。尽管没有统计学差异，但较小尺寸的apo(a) 亚型（0.90 vs. 0.70）和LPA等位基因（0.98 vs. 0.82）的遗传力较高。非裔美国人的遗传力普遍低于白种人，较大LPA等位基因的遗传力差异为 4 倍（0.25 与 0.94，P = 0.001）。在白种人中，年长（≥47 岁）家庭的遗传力总体高于年轻（<47 岁）家庭。总之，Lp(a) 水平和与较小LPA相关的特征尽管种族影响不同，但等位基因很大程度上由遗传学决定。较大LPA等位基因遗传力的种族差异值得进一步研究。