ORPHAN PHENOTYPES IN GERONTOLOGICAL RESEARCH

It is argued that, in addition to investigations of life span paramete rs, a large number of biomedically important phenotypes can be profita bly studied from a gerontological perspective. These would include ''p rivate'' patterns of aging, especially in our own species, which exhib its extraordinary genetic heterogeneity. These, as well as a number of relatively common age-associated phenotypes, have been comparatively neglected by the gerontological community, and therefore warrant the d esignation as ''orphan'' phenotypes. From a tabulation of examples fro m each of the major body systems, five are elaborated upon: ''hyperhip pocampals,'' defined as individuals with intrinsically enhanced functi onal reserve in relevant neural circuitry; patients with a heterogeneo us set of pathologies collectively referred to as ''normal pressure hy drocephalus''; patients with late life activation of herpes zoster; in dividuals with unusually early onset of loss of olfactory function; an d geriatric subjects with unusual sensitivity to ''jet lag.''