Aging is widely studied as a physiological process. Segmental aging can also occur prematurely in Mendelian disorders, and these can act this way as excellent sources of information, specifically for the underlying mechanisms. Adequate recognition of such aging characteristics in Mendelian disorders needs a well-defined phenotype of aging. Here the external phenotype of aging is described that can be recognized in the consulting room without major additional studies. Existing definitions of the signs and symptoms in Elements of Morphology or Human Phenotype Ontology are added or a new definition is suggested if none is available.

中文翻译：

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衰老的外部表型。

衰老作为生理过程被广泛研究。在孟德尔疾病中，节段性衰老也可能过早发生，并且这些可以作为信息的极好来源，特别是针对潜在机制。对孟德尔疾病中此类衰老特征的充分认识需要明确的衰老表型。这里描述了外部的衰老表型，无需大量的额外研究就可以在诊室中识别出该表型。添加了“形态学要素”或“人类表型本体论”中有关体征和症状的现有定义，如果没有可用的建议，则建议使用新的定义。