yán / jiū / rén / yuán / gū / jì / zhè / zhǒng / jí / bìng / de / yí / chuán / lǜ / yuē / wéi / bǎi / fēn / zhī / sì / shí研究人员估计,这种疾病的遗传率约为百分之四十。Researchers estimate that the heritability of this disease is about forty percent.