Efridi Wajahat, Dhamoon Amit S.
Dayton Interventional Radiology Group
SUNY Upstate Medical University
Ochronosis is named for the reddish-brown hue of tissue termed "ochre-like" that was first described by a young physician named Archibald Garrod in the early-19th century. In what he called an "inborn error of metabolism," Archibald Garrod changed history when he coined that term for the obscure "black urine" disease, alkaptonuria. He proposed that ochronosis was due to deposition of a phenolic compound – "alkaptons" polymerizing into connective tissue - because the enzyme that could cleave it was absent and was inherited as a "chemical individuality." This was insightful work given that this preceded the conceptualization of genes. The work of Dr. Garrod would build core foundations on how we understand biochemistry, genetics, and medicine today. Alkaptonuria is iconic for being the initial description of the prototypical autosomal recessive disease. Today we know that expression of the homogentisate 1,2 dioxygenase becomes stunted because of mutations arising in the HGD gene, described as Dr. Garrod's "chemical individuality." Serum levels of homogentisic acid (Alkaptons) concomitantly rise and polymerize into tissue over time. The sequestration effect is also termed as endogenous ochronosis. This article reviews this and the exogenous form of ochronosis, commonly seen as a side-effect of medications that competitively inhibit the same enzyme mentioned above. In contrast to endogenous ochronosis, the deposition is often limited to the skin.
褐黄病得名于一种被称为“赭石样”的组织的红棕色色调，这是19世纪初一位名叫阿奇博尔德·加罗德的年轻医生首次描述的。阿奇博尔德·加罗德将这种晦涩的“黑尿”病——尿黑酸尿症称为“先天性代谢缺陷”，这一术语的提出改变了历史。他提出褐黄病是由于一种酚类化合物——“尿黑酸”聚积在结缔组织中所致，因为能够分解它的酶缺失，并且这种情况作为一种“化学特质”遗传。鉴于这一概念早于基因的概念，这是一项极具洞察力的工作。加罗德医生的工作为我们如今理解生物化学、遗传学和医学奠定了核心基础。尿黑酸尿症作为典型常染色体隐性疾病的最初描述而具有标志性意义。如今我们知道，由于HGD基因发生突变，尿黑酸1,2双加氧酶的表达受到阻碍，这就是加罗德医生所说的“化学特质”。尿黑酸的血清水平随之升高，并随着时间的推移聚积在组织中。这种潴留效应也被称为内源性褐黄病。本文将对这种内源性褐黄病以及外源性褐黄病进行综述，外源性褐黄病通常是竞争性抑制上述同一种酶的药物的副作用。与内源性褐黄病不同，其沉积通常局限于皮肤。
