ABSTRACT
This is a diverse group of diseases, many of them rare and complex, whose nomenclature has undergone radical revision during the last few decades. Many started off with eponymous names, or were classified according to the type of pathology they produced (e.g. lipidosis). Biochemical clarification of the nature of many of them then led to classifications based on underlying enzyme deficiencies. Even more recently the gene defects for some of them have been identified. At present many of them are referred to by several different names. Table 20.1 lists alternative names for some of these conditions.
