Ferreira Carlos R, Gahl William A
Division of Genetics and Metabolism, Children's National Health System, Washington, DC, USA.
Department of Pediatrics, George Washington University School of Medicine and Health Sciences, Washington, DC, USA.
Transl Sci Rare Dis. 2017 Dec 18;2(3-4):101-139. doi: 10.3233/TRD-170015.
Trace elements are chemical elements needed in minute amounts for normal physiology. Some of the physiologically relevant trace elements include iodine, copper, iron, manganese, zinc, selenium, cobalt and molybdenum. Of these, some are metals, and in particular, transition metals. The different electron shells of an atom carry different energy levels, with those closest to the nucleus being lowest in energy. The number of electrons in the outermost shell determines the reactivity of such an atom. The electron shells are divided in sub-shells, and in particular the third shell has s, p and d sub-shells. Transition metals are strictly defined as elements whose atom has an incomplete d sub-shell. This incomplete d sub-shell makes them prone to chemical reactions, particularly redox reactions. Transition metals of biologic importance include copper, iron, manganese, cobalt and molybdenum. Zinc is not a transition metal, since it has a complete d sub-shell. Selenium, on the other hand, is strictly speaking a nonmetal, although given its chemical properties between those of metals and nonmetals, it is sometimes considered a metalloid. In this review, we summarize the current knowledge on the inborn errors of metal and metalloid metabolism.
微量元素是正常生理功能所需的微量化学元素。一些与生理相关的微量元素包括碘、铜、铁、锰、锌、硒、钴和钼。其中，有些是金属，特别是过渡金属。原子的不同电子壳层具有不同的能级，最靠近原子核的电子壳层能量最低。最外层电子的数量决定了该原子的反应活性。电子壳层又分为子壳层，特别是第三壳层有s、p和d子壳层。过渡金属被严格定义为原子具有不完全d子壳层的元素。这种不完全的d子壳层使它们易于发生化学反应，特别是氧化还原反应。具有生物学重要性的过渡金属包括铜、铁、锰、钴和钼。锌不是过渡金属，因为它有一个完整的d子壳层。另一方面，严格来说硒是一种非金属，尽管鉴于其化学性质介于金属和非金属之间，它有时被视为类金属。在本综述中，我们总结了目前关于金属和类金属代谢先天性缺陷的知识。
