Inherited syndromes of congenital enteropathy are rare, with many genetic causes described. Mutations of the AP1S1 gene results in the syndrome of intellectual disability, enteropathy, deafness, peripheral neuropathy, ichthyosis, and keratoderma (IDEDNIK, formerly in the medical literature as MEDNIK). The clinicopathologic features of the enteropathy in IDEDNIK syndrome have not been fully explored. We describe a female infant who presented with metabolic acidosis, lethargy, and 14 watery stools per day. In the intensive care unit she required parenteral nutrition. She was found to have a novel homozygous pathogenic variant in the AP1S1 gene c.186T>G (p.Y62*). Esophagogastroduodenoscopy and colonoscopy at 6 months of age were grossly normal. However, histologic sections of the duodenum showed mild villous blunting and enterocytes with cytoplasmic vacuoles. CD10 immunostaining highlighted the disrupted brush border. MOC31 immunostaining was wild-type with a membranous pattern of expression. Electron microscopy of the duodenum showed scattered enterocytes cells with shortened and disrupted apical microvilli. Although there is a mixed gap diarrhea and disrupted brush border, there are no significant inclusions typical of microvillus inclusion disease, nor tufted enterocytes typical of tufting enteropathy, making the clinical and histopathologic features for this syndrome unique.

中文翻译：

---

足月婴儿 IDEDNIK (MEDNIK) 综合征的临床病理学特征：胃肠道的组织病理学特征和新型 AP1S1 变异的报告。

先天性肠病的遗传性综合征很罕见，有许多遗传原因。AP1S1 基因突变会导致智力障碍、肠病、耳聋、周围神经病、鱼鳞病和角化病等综合征（IDEDNIK，以前在医学文献中称为 MEDNIK）。IDEDNIK 综合征肠病的临床病理特征尚未得到充分探索。我们描述了一名出现代谢性酸中毒、嗜睡和每天 14 次水样便的女婴。在重症监护室，她需要肠外营养。她被发现在 AP1S1 基因 c.186T>G (p.Y62*) 中有一个新的纯合致病性变异。6 个月大时的食管胃十二指肠镜检查和结肠镜检查大体正常。然而，十二指肠的组织学切片显示轻度绒毛钝化和具有细胞质空泡的肠上皮细胞。CD10 免疫染色突出显示了破坏的刷状缘。MOC31 免疫染色为野生型，具有膜表达模式。十二指肠电子显微镜显示散在的肠上皮细胞，顶端微绒毛缩短且破裂。尽管存在混合性间隙腹泻和破坏的刷状缘，但没有微绒毛包涵体病典型的显着包涵体，也没有簇状肠病典型的簇状肠细胞，使得该综合征的临床和组织病理学特征独特。