假性醛固酮减少症Ⅰ型（pseudohypoaldosteronism type Ⅰ，PHA Ⅰ）是一种罕见的遗传性疾病，主要由醛固酮受体缺乏、醛固酮与其受体结合减少或完全不能结合而引起，表现为新生儿时期出现低钠血症、高钾血症、代谢性酸中毒，伴有脱水、呕吐、体质量下降，甚至休克等。该病分为盐皮质激素受体突变的肾型PHA Ⅰ和上皮钠通道3个亚单位（α、β或γ）中任何一个突变的多脏器型PHA Ⅰ。肾型PHA Ⅰ是常染色体显性遗传，由醛固酮受体突变引起，伴有孤立的肾性失盐综合征，与多脏器型相比，临床症状较轻，且随着年龄增加，症状可改善。但不同患儿根据其失盐程度，症状有所差异，如未及时治疗，可能因反复脱水导致休克，甚至因高钾导致心脏骤停。目前研究发现人类盐皮质激素受体由NR3C2基因编码，位于4q31.1与4q31.2区域之间。该文报告1例新发NR3C2基因（4q31.22）变异所致的肾型PHA Ⅰ患儿，胎儿期检测出染色体异常，且在生后表现出高血压、高血钾和低钠血症，伴随血浆醛固酮水平显著升高（˃2 000 pg/mL）。全基因染色体检测显示患儿存在NR3C2基因4q31.22区域微缺失，确诊为肾型PHA Ⅰ。口服浓氯化钠后电解质紊乱得以纠正，1个月后病情平稳。

Pseudohypoaldosteronism type Ⅰ (PHA Ⅰ) is a rare inherited disease, mainly caused by the deficiency of the aldosterone receptor or by reduced or absent binding between aldosterone and its receptor. It typically manifests as neonatal hyponatremia, hyperkalaemia, metabolic acidosis, accompanied by dehydration, vomiting, weight loss, and even shock. PHA Ⅰ is classified into renal-type with mutations in the salt corticosteroid receptor and multi-organ with mutations in any of the three subunits of the epithelial sodium channel (α, β or γ). The renal-type, which is inherited in an autosomal dominant manner, is caused by mutations in the aldosterone receptor with an isolated nephrogenic salt-loss syndrome, and the clinical symptoms are milder compared with those of the multi-organ type, which may improve with age. However, severity varies among individuals depending on the degree of salt loss, and if not treated in time, it may lead to shock due to repeated dehydration or even cardiac arrest due to high potassium. Currently, domestic studies have found that the human salt corticosteroid receptor is encoded by the NR3C2 gene, which is located between the regions of 4q31.1 and 4q31.2. This case reports a child with nephrogenic PHA Ⅰ due to a new-onset variant of the NR3C2 (4q31.22) gene, who had chromosomal anomalies in the fetus and demonstrated high blood pressure, high blood potassium and low sodium after birth. The diagnosis of renal neonatal PHA Ⅰ was confirmed by the presence of a microdeletion of NR3C2 gene (4q31.22 region) in the child, which was demonstrated by a genome-wide chromosomal assay and accompanied by a significant elevation of the plasma aldosterone level (>2 000 pg/mL), and by the presence of a microdeletion of NR3C2 gene (4q31.22 region) in the child. Electrolyte disorders were corrected after oral administration of concentrated sodium chloride, and the condition remained stable at the 1-month follow-up.