Asthma: A Multifactorial Condition

What do Jerome Bettis (Pittsburgh Steelers), Amy Van Dyken (Olympic swimmer) and Jackie Joyner-Kersee (Olympic gold medalist) have in common? Asthma.

The symptoms of this disease are frightening: shortness of breath, tightening of the chest, feelings of suffocation and the inability to take a complete deep breath. These are the symptoms of a condition that affects children, adults, males, females and different ethnic groups. It ranks 8th in prevalence among chronic conditions in the United States, it is the leading cause of serious illness among children and its incidence appears to be rising.

Asthma is a multifactorial condition, one that is influenced by both genetic and environmental factors. The airways of these individuals are hyperactive and sensitive to many environmental stimuli including smoke, pollen, animal dander, exercise, cold air, certain scents and stress.

The American Lung Association describes asthma as “a disease that discriminates”. In the Hispanic populations, Puerto Ricans have a higher rate of asthma than other Latino groups. African-Americans have an asthma prevalence that is almost twice that of the Caucasian population.

Multifactorial disorders, including asthma, are common and a major contributor to human morbidity, illness and death. Much is known about the environmental triggers in asthma but little is known of the genetics. The term, heritability, refers to the proportion of the cause of a disease that can be attributed to genetic factors rather than environmental factors. One source listed the heritability of asthma at 80%. The greater the value for heritability, the greater is the role of genetic factors in the condition.

Much research is being conducted to identify specific genes in this condition. A July 2002 article in Nature identified a possible asthma susceptibility gene called ADAM33. A Johns Hopkins research team in 2001 identified sites on chromosomes 12 and 17 in which genes may interact and collaborate to cause the disease. Learning more about the genetic pathways may yield new treatments in the prevention of asthma symptoms.

Asthma should be a controllable disease, allowing individuals to live relatively normal lifestyles, but it requires patients to use medications as prescribed, avoid known environmental triggers and consult their physicians as recommended.