569still within the norm for his or age whereas prior to illness, the performance might
have been >50 % as compared to average persons of his age. People age at different
rates depending on several factors including genetic, environmental and life style.
A physical active 70-year old may have been performing at the level of a 50-year old
prior to onset of disease. In spite of slight impairment of function, his performance
may still be within the normal range for his chronological age but may indicate
early disease. This factor may be overlooked by the physician but a personalized
approach takes this into consideration as a person is his or her own control even
within the span of time.
Pharmacogenetics and Adverse Drug Reactions
Prevalence of both therapeutic failures and adverse drug reactions are signifi cantly
higher in older than in younger subjects. This might be due to higher use of poly-
pharmacy and multiple co-existing diseases in the elderly. Nevertheless, other
explanations must also be sought. There are alterations in metabolism and pharma-
cokinetics due to impairment of renal and hepatic functions that are common in the
elderly. Pharmacogenetics of drug metabolizing enzymes, drug transporters and
receptors should not be overlooked.
Personalized Management of Skin Disorders
There is an overlap between cosmetics, skin care and therapy of skin disorders.
Everything from ancient herbs to sheep placentas has been used to make skin
care products.
Genetic Testing for Personalized Skin Care
Lab 21 (New York) claims that by taking DNA samples from customers it can pro-
vide a personalized skin cream based on specifi c variations of fi ve genes related to
skin sensitivity and aging. The only way to get the formula is to visit one of the
company’s shops. After answering a 10-min online questionnaire about their skin,
ethnic origins, pore size and hydration, the customers get the inside of their mouths
swabbed for a DNA sample. The test and the sample are sent to a laboratory to be
analyzed and the customized skin creams are generated based on the results. Some
geneticists and dermatologists are rather skeptical about this product. It is not a
product that is genetically programmed for their skin. Simply studying a DNA sam-
ple, without the knowledge of genes that regulate skin health is unscientifi c. Another
issue is privacy because the swabs taken at the shops contain a complete set of
an individual’s genetic information including genes relevant to several diseases.
Personalized Management of Skin Disorders