近端肾小管酸中毒（Proximal renal tubular acidosis、pRTA、或"2型肾小管酸中毒(RTA 2)")是一种RTA的类型，由于近曲小管细胞从尿中再吸收"滤过的碳酸氢盐之失败所引起的，从而导致有尿液碳酸氢盐损耗及酸血症(acidemia)。因"远程闰细胞"(istal intercalated cell)功能正常，所以酸血症比远程肾小管酸中毒(dRTA)来较不严重、且尿液可以酸化至pH值小于<5.3>。 pRTA也有几个病因，且有时可能存在一个孤立的缺陷、但通常与称为范康尼氏症候群的"近端小管细胞普偏性的功能障碍"有关，其中范康尼氏症候群也有磷酸盐尿，肾性糖尿(glycosuria)，氨基酸尿(aminoaciduria)，尿酸尿(uricosuria)及肾小管蛋白尿等尿液病症。

Proximal renal tubular acidosis (pRTA) or Type 2 Renal tubular acidosis (RTA) is a type of RTA caused by a failure of the proximal tubular cells to reabsorb filtered bicarbonate from the urine, leading to urinary bicarbonate wasting and subsequent acidemia. The distal intercalated cells function normally, so the acidemia is less severe than dRTA and the urine can acidify to a pH of less than 5.3. pRTA also has several causes, and may occasionally be present as a solitary defect, but is usually associated with a more generalised dysfunction of the proximal tubular cells called Fanconi syndrome where there is also phosphaturia, glycosuria, aminoaciduria, uricosuria and tubular proteinuria.