未确定的中风因素阻碍了大部分年轻患者的最佳二级预防。我们探讨了是否遗传筛查无确定潜力的克隆造血干细胞 (CHIP) 可识别具有特定治疗需求的髓细胞前体病变或隐匿性骨髓肿瘤的患者，从而增加二级预防的有效性。我们对18到60岁的急性脑缺血患者进行了56个在血液肿瘤中经常突变的基因的定向测序。我们将CHIP的流行率与来自Nijmegen Biomedical Study（n = 1604）和UK Biobank（n = 101,678）的年龄匹配的健康对照组进行比较。怀疑存在高危CHIP或骨髓肿瘤的患者被邀请进行更深入的血液学评估。研究包括248名连续患者（39％女性），其中176名（71％）的中风因素是隐匿性的。51名（21％）患者患有CHIP，比普通人口高3倍（Nijmegen Biomedical Study为7.7％，UK Biobank为11.9％，对比一下，Nijmegen生物医学研究的为2.6％，UK Biobank为4.1％；对于两者P <0.001）。患有CHIP的患者年龄较大（中位数[四分位数范围]为53 [50-59]岁，而无CHIP的患者为51 [41-56]岁，P <0.001），颈动脉平均内膜厚度较高（0.68 [0.58-0.80]毫米，而无CHIP的患者为0.59 [0.51-0.73]毫米，P =0.009）， 且动脉粥样硬化负担较高（29.4％比16.7％，P =0.04）。我们邀请了11名患者（4.4％）进行更深入的血液学评估，其中7名患者被诊断出患有高危CHIP，而另外2名患者被诊断出有需进行细胞减少治疗的新的增生性骨髓瘤。通过对患有主要为未确定性的中风病因的患者进行基因筛查，我们发现CHIP的流行率比普通人高3倍。我们确定了高危CHIP和以前的含蓄骨髓增殖性疾病可能是中风病因的潜在因素在4.4％和1％的患者中，这强调了年轻中风患者的基因筛查在诊断和治疗方面的重要作用。未来的研究应探究CHIP对中风复发和最佳二级预防的作用。

Undetermined stroke etiology hampers optimal secondary prevention in a large proportion of young patients. We explored whether genetic screening for clonal hematopoiesis of indetermined potential (CHIP), a novel risk factor for stroke, could identify patients with myeloid precursor lesions or covert myeloid neoplasm requiring specific treatment.We performed targeted sequencing on 56 genes recurrently mutated in hematologic neoplasms in a prospective cohort of patients with acute brain ischemia between 18 and 60 years. CHIP prevalence was compared with age-matched healthy controls from the Nijmegen Biomedical Study (n=1604) and the UK Biobank (n=101 678). Patients with suspicion of high-risk CHIP or myeloid neoplasm were invited for further hematologic evaluation.We included 248 consecutive patients (39% women) of whom 176 (71%) had cryptogenic stroke etiology. Fifty-one (21%) patients had CHIP, 3-fold more than in the general population (7.7% versus 2.6% for the Nijmegen Biomedical Study and 11.9% versus 4.1% for UK Biobank; P<0.001 for both). Patients with CHIP were older (median [interquartile range], 53 [50-59] versus 51 [41-56] years; P<0.001), had higher carotid intima-media thickness (0.68 [0.58-0.80] versus 0.59 [0.51-0.73] mm; P=0.009), and had higher burden of atherosclerosis (29.4% versus 16.7%; P=0.04). We invited 11 patients (4.4%) for further hematologic assessment, which in 7 led to the diagnosis of high-risk CHIP and in 2 to the new diagnosis of a myeloproliferative neoplasm with indication for cytoreductive therapy.Using genetic screening for myeloid disorders in patients with stroke of predominantly undetermined etiology, we found a 3-fold higher CHIP prevalence than in the general population. We identified high-risk CHIP and previously covert myeloproliferative neoplasms as potential stroke etiologies in 4.4% and 1% of patients, respectively. Our findings demonstrate the diagnostic and therapeutic yield of genetic screening in young patients with stroke. Future studies should investigate the role of CHIP for stroke recurrence and optimal secondary prevention.