用rstudio找出这段文字的高频词汇及字母Genome-wide association studies have identified manyvariants affecting susceptibility to disease Now threestudies use this approach to study adult height variation in acombined s

高频词汇：genome-wide, association, studies, identified, variants, affecting, susceptibility, disease, approach, study, adult, height, variation, combined, sample, size, individuals, report, total, validated, influencing, trait.

高频字母：e, t, a, i, n, s, r, o, u.