Purpose

There are limited genes known to cause primary ciliary dyskinesia (PCD)–associated asthenozoospermia. In the present study, we aimed to expand the spectrum of mutations in PCD and to provide new information for genetic counseling diagnoses and the treatment of male infertility in PCD.

Methods

One sterile patient with typical situs inversus was recruited to our center, and semen sample was collected. We performed whole-exome sequencing (WES) on the patient to identify the pathogenic mutations associated with PCD and used transmission electron microscopy to investigate spermatozoal ultrastructure. In addition, western blotting and immunofluorescence staining were used to confirm the untoward impact of the variant on the expression of LRRC6, as well as on the dynein arm proteins in the patient’s spermatozoa.

Results

We identified a homozygous nonsense variant c.749G>A (p.W250*) of LRRC6 in the PCD patient. This variant severely impaired LRRC6 expression and further led to negative effects on dynein arm protein expression in the spermatozoa of the affected individual, which eventually caused defects in sperm ultrastructure and motility. Moreover, we are the first to report a positive prognosis using intracytoplasmic sperm injection (ICSI) for LRRC6-associated male infertility.

Conclusions

Our findings strongly implicated the homozygous mutation of c.749G>A (p.W250*) in LRRC6 as a new genetic cause of PCD, uncovering its involvement in defective sperm flagella and poor sperm motility. Furthermore, we posit that patients with LRRC6 mutations may have good outcomes with ICSI treatment. These findings add to the literature on the genetic diagnoses and treatment of male infertility associated with PCD.

中文翻译：

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新的 LRRC6 突变对原发性纤毛运动障碍患者鞭毛超微结构的影响

目的

已知会导致原发性纤毛运动障碍 (PCD) 相关的弱精子症的基因有限。在本研究中，我们旨在扩大 PCD 的突变谱，并为 PCD 的遗传咨询诊断和男性不育症的治疗提供新的信息。

方法

我们中心招募了一名患有典型内脏倒置的不育患者，并收集了精液样本。我们对患者进行了全外显子组测序 (WES) 以确定与 PCD 相关的致病突变，并使用透射电子显微镜来研究精子超微结构。此外，蛋白质印迹和免疫荧光染色用于确认变体对 LRRC6 表达以及患者精子中动力蛋白臂蛋白的不利影响。

结果

我们在 PCD 患者中鉴定了LRRC6的纯合无义变体 c.749G>A (p.W250*) 。这种变异严重损害了 LRRC6 的表达，并进一步导致对受影响个体精子中动力蛋白臂蛋白表达的负面影响，最终导致精子超微结构和运动缺陷。此外，我们是第一个报告使用胞浆内精子注射 (ICSI) 治疗LRRC6相关的男性不育症的积极预后。

结论

我们的研究结果强烈暗示 LRRC6 中c.749G >A (p.W250*) 的纯合突变是PCD 的新遗传原因，揭示了它与精子鞭毛缺陷和精子活力差有关。此外，我们假设具有LRRC6突变的患者可能在 ICSI 治疗中获得良好的结果。这些发现增加了有关与 PCD 相关的男性不育症的基因诊断和治疗的文献。