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    Alpha-1 antitrypsin deficiency (AAT deficiency) is an inherited disease, which means it's passed down to you by your parents. It can lead to lung disease, especially if you smoke.

    If you think there's a chance you have AAT deficiency, you may want to be tested. Though there's no cure yet, you can make smart moves to protect your lungs and be sure you get the right treatments.

    Who Is at Risk?

    If you have COPD, your doctor may check to see if you have AAT deficiency. 

    Symptoms of AAT deficiency include:

    • Shortness of breath
    • Wheezing
    • Frequent respiratory infections like colds, flu, or bronchitis
    • Fatigue
    • Unexplained weight loss

    Since AAT deficiency runs in families, you may want to be tested if you have a relative with it.

    Two Kinds of AAT Deficiency

    People who develop the illness have two faulty genes, one passed from each parent. Genes are part of your DNA.

    It's possible to have just one faulty gene, which makes you a carrier. You won't get AAT deficiency yourself, but you can pass it to your children.

    If you inherit two faulty genes, you can develop emphysema in your 40s or 50s -- or you may never get symptoms of lung disease. You may never even know you have AAT deficiency. So although a test may show that you have both genes, it cannot say for certain what will happen to your health.

    Blood Tests and Lung Checks

    The best way to diagnose AAT deficiency is with a test that looks at your DNA. Your doctor will take a blood sample or swab the inside of your cheek. Lab workers will check the sample for the faulty genes that cause AAT deficiency.

    Another blood test measures how much of the AAT protein is present in your body. If the level is much lower than normal, that's a sign of AAT deficiency.

    Your doctor may also suggest tests to look for lung disease. These may include:

    • A CT scan. This type of X-ray can spot emphysema.
    • A lung test to measure how much air you breathe in and out in a short time.
    • A blood gas test to measure how much oxygen is in your blood.