Premature ovarian insufficiency (POI) is characterised by amenorrhea associated with elevated follicle stimulating hormone (FSH) under the age of 40 years and affects 1–3.7% women. Genetic factors explain 20–30% of POI cases, but most causes remain unknown despite genomic advancements. We used whole exome sequencing (WES) in four Iranian families, validated variants via Sanger sequencing, and conducted the Acyl-cLIP assay to measure HHAT enzyme activity. Despite ethnic homogeneity, WES revealed diverse genetic causes, including a novel homozygous nonsense variant in , impacting synaptonemal complex (SC) assembly, in the first family. Interestingly, the second family had two independent causes for amenorrhea – the mother had POI due to a novel homozygous loss-of-function variant in (required for chromosomal stability) and her daughter had primary amenorrhea due to a novel homozygous (required for gonadotropic signalling) frameshift variant. WES analysis also provided cytogenetic insights. WES revealed one individual was in fact 46, XY and had a novel homozygous missense variant of uncertain significance in , potentially responsible for complete sex reversal although functional assays did not support impaired HHAT activity. In the remaining individual, WES indicated likely mosaic Turners with the majority of X chromosome variants having an allelic balance of ∼85% or ∼15%. Microarray validated the individual had 90% 45,XO. This study demonstrates the diverse causes of amenorrhea in a small, isolated ethnic cohort highlighting how a genetic cause in one individual may not clarify familial cases. We propose that, in time, genomic sequencing may become a single universal test required for the diagnosis of infertility conditions such as POI.

中文翻译：

---

种族同质群体中闭经的多种遗传原因和不断发展的诊断方法

卵巢早衰 (POI) 的特点是与 40 岁以下卵泡刺激素 (FSH) 升高相关的闭经，影响 1-3.7% 的女性。遗传因素可以解释 20-30% 的 POI 病例，但尽管基因组取得了进步，但大多数原因仍然未知。我们在四个伊朗家庭中使用了全外显子组测序 (WES)，通过 Sanger 测序验证了变异，并进行了 Acyl-cLIP 测定来测量 HHAT 酶活性。尽管存在种族同质性，WES 揭示了不同的遗传原因，包括影响第一家族中联会复合体 (SC) 组装的新型纯合无义变异。有趣的是，第二个家庭有两个独立的闭经原因——母亲因一种新的纯合性功能丧失变异（染色体稳定性所需）而患有 POI，而她的女儿因一种新型纯合性（促性腺激素信号传导所需）而患有原发性闭经。 ）移码变体。 WES 分析还提供了细胞遗传学见解。 WES 揭示了一个个体实际上是 46, XY，并且具有一种新的纯合错义变异，其意义不确定，可能导致完全性逆转，尽管功能测定不支持 HHAT 活性受损。在剩下的个体中，WES 表明可能是嵌合体 Turners，大多数 X 染色体变异的等位基因平衡为 ∼85% 或 ∼15%。微阵列验证该个体具有 90% 的 45,XO。这项研究证明了一个小型、孤立的种族群体中闭经的多种原因，强调了一个人的遗传原因可能无法澄清家族病例。我们建议，随着时间的推移，基因组测序可能成为诊断 POI 等不孕症所需的单一通用测试。