Genetic causes account for 10–15% of male factor infertility, making the genetic investigation an essential and useful tool, mainly in azoospermic and severely oligozoospermic men. In these patients, the most frequent findings are chromosomal abnormalities and Y chromosome long arm microdeletions, which cause a primary severe spermatogenic impairment with classically increased levels of FSH. On the other hand, polymorphisms in the FSH receptor (FSHR) and FSH beta chain (FSHB) genes have been associated with different FSH plasma levels, due to variations in the receptor sensitivity (FSHR) or in the production of FSH from the pituitary gland (FSHB). Here, we describe an unusual patient with a combined genetic alteration (classic AZFc deletion of the Y chromosome and TT homozygosity for the -211G>T polymorphism in the FSHB gene (rs10835638)), presenting with cryptozoospermia, severe hypospermatogenesis, and normal LH and testosterone plasma concentrations, but low FSH levels. The patient partially benefitted from treatment with FSH (150 IU three times/week for 6 months) which allowed him to cryopreserve enough motile spermatozoa to be used for intracytoplasmic sperm injection. According to our knowledge, this is the first report of an infertile man with AZFc microdeletion with low FSH plasma concentrations related to homozygosity for the -211G>T polymorphism in the FSHB gene.

中文翻译：

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由于 FSHB 基因同时多态性，Y 染色体 AZFc 微缺失和 FSH 水平低的隐生精子症不育男性：病例报告

遗传因素占男性因素不育症的 10-15%，这使得遗传研究成为一种重要且有用的工具，主要针对无精症和严重少精症的男性。在这些患者中，最常见的发现是染色体异常和 Y 染色体长臂微缺失，这会导致原发性严重生精障碍，并伴有典型的 FSH 水平升高。另一方面，由于受体敏感性 (FSHR) 或垂体产生 FSH 的变化，FSH 受体 (FSHR) 和 FSH β 链 (FSHB) 基因的多态性与不同的 FSH 血浆水平相关。 （FSHB）。在这里，我们描述了一名不寻常的患者，其具有组合遗传改变（Y染色体的经典AZFc缺失和FSHB基因中-211G>T多态性的TT纯合性（rs10835638）），表现为隐精症、严重精子生成不足和正常LH和血浆睾酮浓度较高，但 FSH 水平较低。患者部分受益于 FSH 治疗（150 IU，每周 3 次，持续 6 个月），这使他能够冷冻保存足够的活动精子，用于胞浆内单精子注射。据我们所知，这是首次报道患有AZFc微缺失的不育男性，其血浆FSH浓度较低，这与FSHB基因中-211G>T多态性的纯合性有关。