Gene Linked To Asthma In Blacks Discovered

woman at work looking at laptopU.S. researchers have discovered a genetic mutation unique to African Americans that could help explain why blacks are so susceptible to asthma.

Prior studies looking for asthma genes have turned up several, but most of the studies have been too small to confirm these genes or to detect genetic changes unique to different races.

The new study, published on Sunday in the journal Nature Genetics, pools research from nine different research groups looking for genes associated with asthma among ethnically diverse North American populations.

It confirmed four genes that had been seen in previous studies and a fifth that shows up only in people of African descent.

“This is the first discovery of a gene where we see a signal in African Americans only,” Dan Nicolae of the University of Chicago, a study author and co-chair of a national research consortium called EVE that identified the gene, said in a telephone interview.

“The rates of asthma in different ethnic groups are different. African Americans have shown increasing asthma rates. We don’t know why. It can be due to changing environmental risk factors,” Nicolae said.

But, he said, the new findings suggest genetics also play a significant role.

“Understanding these genetic links is an important first step toward our goal of relieving the increased burden of asthma in this population,” said Dr. Susan Shurin, acting director of the National Heart, Lung, and Blood Institute, one of the National Institutes of Health, which co-funded the study.

Asthma affects more than 300 million people globally, but effects vary widely. According to the researchers, U.S. asthma rates in 2001 to 2003 ranged from 7.7 percent among European Americans to 12.5 percent among African Americans.

Carole Ober of the University of Chicago, who co-leads the EVE consortium, said the findings confirm the significance of four genes identified in a large European asthma genetics study published last year called GABRIEL, offering strong evidence that these genes are important across ethnic groups.

But because the study was so large and ethnically diverse — including data on European Americans, African Americans, African Caribbeans and Latinos — it enabled the researchers to find this new gene variant that exists only in African Americans and African Caribbeans.

This new variant, located in a gene called PYHIN1, is part of a family of genes linked with the body’s response to viral infections, Ober said.

“We were very excited when we realized it doesn’t exist in Europe,” she said.

The team stressed that each gene variant on its own plays only a small role in increasing asthma risk, but that risk could be multiplied when combined with other risk genes and with environmental factors, such as smoking, that also increase asthma risk.

“It’s been extraordinarily challenging to try to find variation in genes that are associated with risk for developing asthma that can be replicated among populations. It’s a very complex disease with a lot of genes and a lot of environmental factors influencing risk,” Ober said.

The findings now give researchers new areas to explore in understanding the interplay of genetics and the environment in asthma risk, and may lead to better treatments.

“What you see here in this paper is only the beginning,” Nicolae said.

How To Prevent Heat Stroke

african american man drinking water ( — Heat stroke is a form of hyperthermia, where the body’s temperature is abnormally high (usually 104 F or higher). Unlike other heat-related injuries, such as heat cramps and heat exhaustion, heat stroke is a true medical emergency that is often fatal if not properly and promptly treated.

Why Does Heat Stroke Happen

The body normally generates heat as a result of metabolism, and is usually able to dissipate the heat by radiation of heat through the skin or by evaporation of sweat. However, in extreme heat, high humidity, or vigorous physical exertion under the sun, the body may not be able to get rid of that excess heat and the body temperature rises, sometimes up to 106 F (41.1 C) or higher.

Another cause of heat stroke is dehydration. A dehydrated person may not be able to sweat fast enough to dissipate heat, which causes the body temperature to rise.

Who Does Heat Stroke Affect The Most?

Those most susceptible to heart strokes include:

• Infants
• The elderly (often with associated heart disease, lung diseases, kidney diseases, or who are taking medications that make them vulnerable to dehydration and heat strokes)
• Athletes
• Individuals who work outside and physically exert themselves under the sun.

What Are Heat Stroke Symptoms and Signs?

Symptoms of heat stroke can sometimes mimic those of heart disease or other conditions. Sometimes a person will experiences symptoms of heat exhaustion before progressing to a heat stroke.

Signs and symptoms of heat exhaustion include:

• Nausea
• Vomiting
• Fatigue
• Weakness
• Headache
• Muscle Cramps/Aches
• Dizziness

Some individuals will develop symptoms of heat stroke suddenly and rapidly without warning or heat exhaustion symptoms. Also, it’s important to note that different people can experience different heat stroke symptoms. Some of the more common symptoms include:

• High body temperature
• Absence of sweating, with hot, red and/or flushed dry skin
• Rapid pulse
• Difficulty breathing
• Strange behavior
• Hallucinations
• Confusion
• Agitation
• Disorientation
• Seizure
• Coma

How Do You Treat A Heat Stroke Victim?

Victims of heat stroke must receive immediate treatment to avoid permanent organ damage. The essential steps that need to be taken include:

• Cool the victim as quickly as possible! Help get them to a shady area, remove clothing, apply cool or tepid water to the skin (for example, you may spray the victim with cool water from a garden hose), fan the victim to promote sweating and evaporation, and place ice packs under the armpits and groin.

• If the person is able to drink liquids, have them drink cool water or other cool beverages that do not contain alcohol or caffeine.

• Monitor body temperature with a thermometer and continue cooling efforts until the body temperature drops to 101 to 102 F (38.3 to 38.8 C).

• Always notify emergency services (911) immediately. If their arrival is delayed, they can give you further instructions for treatment of the victim.

How Can Heat Stroke Be Prevented?

• The most important way to prevent heat strokes are to avoid becoming dehydrated and to avoid vigorous physical activities in hot and humid weather.

• If you have to perform physical activities in hot weather, drink plenty of fluids (such as water and sports drinks). Remember that you will also need to replenish your electrolytes (such as sodium) as well, especially if you sweat excessively or are performing vigorous activity in the sunlight for prolonged periods of time.

• It is important to avoid alcohol and caffeinated beverages, such as certain soft drinks, tea and coffee, since both alcohol and caffeine cause dehydration.

• Take frequent breaks to hydrate yourself. Wear hats and light-colored, lightweight, loose clothes.

• Keep cars locked when not in use and never, ever, leave children or pets unattended in a locked car.