目前明确的3个不重叠的AZF亚区分别为:AZFa、AZFb和AZFc。常见的AZF缺失包括5种缺失模式:AZFa、AZFb、AZFc、AZFb+c、和AZFa+b+c。其中AZFc区域缺失的发生率最高约占80%,临床表型从无精子到中度或重度少精子均有发生。AZFb发生率约1~5%,表现为生精阻滞,睾丸内可见精原和精母细胞,但无精子生成。AZFa缺失较少见,整个AZFa区域的缺失通常表现为支持细胞综合症(sertoli cell only syndrome, SCOS),为绝对的无精子症,同时伴有睾丸缩小等。
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