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VOL. 69 (3), GENES VIEJOS

que se caracterizan por la rápida instauración de condiciones normalmente asociadas con
el envejecimiento, se asocian con inestabilidad genómica. Dos de estos procesos, el
síndrome de Werner y el síndrome de Rothmund-Thompson, están producidos por
mutaciones en genes que codifican proteínas relacionadas con RecQ. RecQ es una ADN-
helicasa; una enzima que utiliza la energía de la hidrólisis de los trifosfatos nucleotíficos
para romper el emparejamiento de bases entre las hebras de los ácidos nucleicos,
convirtiendo los ácidos nucleicos de doble hebra en monocatenarios. Las helicasas son
esenciales en prácticamente todos los aspectos del metabolismo de los ácidos nucleicos –
replicación, transcripción, trducción, reparación y recombinación.

Podría suponerse que los beneficiarios más inmediatos de la investigación en
curso deberían ser los pacientes geriátricos. Sin embargo, el trabajo debería dirigirse a un
nuevo médico que confeccione estategias para prolongar la vida de forma
individualizada a sus pacientes: los pediatras. El mejor medio para asegurar la salud de
los ancianos puede estar en mejorar el bienestar de nuestros niños.

Palabras clave: Envejecimiento.— Cáncer.— Inestabilidad genómica.—
Lipodistrofia.—Síndromes progeroides.

SUMMARY
Old genes

“Comics, poets, and sages have all expounded on what it means to age. But
only now can we begin to converse about the biology of aging. Why and how we age?
Researches have asked these questions, and some answers are finally emerging”. Evolu-
tionary history has determined that individuals thrive for long enough to produce and
nurture their offspring. Thereafter, the ageing process involves a slow decline in physio-
logical vigour and an increasing susceptibility to age-related disease. A number of hu-
man genes have been identified in which mutations can lead to the accelerated emer-
gence of features of senescence. Studies of these genes, and of the functions of their pro-
tein products, may lead to a clearer understanding of the nature of senescence, and could
provide clues for ways in which ageing might be retarded.

The progeroid syndromes are conditions that produce premature aging and a
shortened life expectancy. The most striking feature of these rare disorders is extremely
accelerated aging. Affected children develop all of the external signs of old age. Unlike
normal aging, however, progeroid syndromes also include such features as lack of ovar-
ian or testicular activity (including sterility and absence of menstrual periods) and un-
usually short stature. Thus, progeria is not an exact model of accelerated aging.

Genome instability has long been proposed to be a major factor in the aging
process. The contribution of genome instability to aging is underscored by the finding
that several of the segmental progeroid syndromes, which are characterized by early on-
set of conditions normally associated with aging, are associated with genome instability.
Two such diseases, Werner syndrome and Rothmund-Thomson syndrome, are caused by

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