Abstract: Objective　To investigate the etiological composition and clinical features of primary adrenal insufficiency（PAI） in 42 children diagnosed in different age groups. Methods　Clinical data and genetic test results of 42 children hospitalized for PAI at Hebei Children’s Hospital between January 2018 and December 2024 were retrospectively collected. The patients were divided into two groups based on the age at definitive diagnosis：a 0~3-month group and a >3-month group. The etiological composition and clinical features were compared between the two groups. Results　A total of 42 children with PAI were included（26 males，16 females）. The age at presentation ranged from 30 hours to 12 years and 6 months，with a median age of 2 years and 8 months. The 0~3-month group comprised 15 children，and the >3-month group comprised 27 children. There were 26 cases presenting with 21-hydroxylase deficiency（21-OHD），which was the most common etiology. In the 0~3-month group，the salt-wasting form of 21-OHD was predominant（10/15，66.7%）. In the >3-month group，the simple virilizing form of 21-OHD was more common（10/27，37.0%）. The most common clinical manifestations in the 42 cases were hyperpigmentation，abnormal external genitalia，and electrolyte imbalances. Electrolyte imbalances（12/15，80.0%） and anemia（8/15，53.3%）were significantly more frequent in the 0~3-month group compared to the >3-month group（P<0 .05）. There were no deaths in the 42 cases of PAI. Hormone replacement and symptomatic treatment led to significant improvement in 30 out of 42 patients（71 .4%）. Conclusion　The etiological composition of PAI in children differs according to the age at diagnosis，with significantly different clinical manifestations. The salt-wasting form of 21-OHD is most common in infants diagnosed within 0~3 months，demonstrating a high genotype-phenotype correlation，and these patients are more prone to electrolyte imbalances，anemia. In children diagnosed after 3 months，the simple virilizing form of 21-OHD is frequent，and rare causes like X-linked adrenoleukodystrophy and X-linked adrenal hypoplasia congenita are notable；phenotypes are diverse in this group.

Key words: primary adrenal insufficiency, child, 21-hydroxylase deficiency, X-linked adrenal hypoplasia congenita, X-linked adrenoleukodystrophy

摘要： 目的　探讨42 例不同年龄组确诊的儿童原发性肾上腺皮质功能减退症（PAI）的病因构成及临床特征。方法　回顾性收集河北省儿童医院2018 年1 月至2024 年12 月收治的42 例PAI 住院患儿的临床资料及基因检测结果。按明确诊断PAI 的年龄分为0~3 月龄组、>3 月龄组，比较其病因构成和临床特征。结果　共纳入42 例儿童PAI，社会性别男性26 例，女性16 例，就诊年龄出生30 h 至12.5 岁，中位年龄2.67 岁。0~3 月龄组15 例，>3 月龄组27 例。21- 羟化酶缺乏症（21-OHD）共26 例，为最常见病因。0~3 月龄组大部分为21-OHD 失盐型（10/15，66.7%），>3 月龄组21-OHD 单纯男化型（10/27，37.0%）多见。42 例患儿临床表现以色素沉着、电解质紊乱、外生殖器异常最为常见。0~3 月龄组电解质紊乱（12/15，80.0%）、贫血（8/15，53.3%）较>3 月龄组多见（P<0 .05）。42 例PAI 无死亡病例，30 例（30/42，71.4%）经激素替代及对症治疗明显缓解。结论　在不同年龄确诊的儿童 PAI 病因构成不同，临床表现差异显著。0~3 月龄患儿21-OHD 失盐型最为多见，基因型- 表型高度相关，更容易发生电解质紊乱、贫血。>3 月龄患儿21-OHD 单纯男化型多见，罕见病因以X 连锁肾上腺脑白质营养不良、X连锁先天性肾上腺发育不良为主，不同个体表型多样。

关键词: 原发性肾上腺皮质功能减退症, 儿童, 21- 羟化酶缺乏症, X 连锁先天性肾上腺发育不良, X 连锁肾上腺脑白质营养不良