Somewhere between 20% and 25% of the population seem to have the genetic makeup to be at risk for thyroid dysfunction. If you or a close relative has had a thyroid problem you should encourage other relatives to discuss this risk with their family physicians. Some may need a (TSH test to see if their thyroid is over- or underactive. Others may have thyroid related disorders and need other forms of treatment.
Family members can share the inheritance that leads to thyroid problems. If your mother or grandmother or aunt had goiter or were hypo- or hyperthyroid, your chances of getting such a problem are higher. Tell your doctor about your background.The "thyroid genes," so-called, increase the likelihood that your thyroid will enlarge or become overactive due to Graves' disease or underactive due to Hashimoto's chronic thyroiditis sometime in your life. The chance of a problem increases with age and in the postpartum period if you are a woman. Also associated with those genes may be: the beginnings of gray hair before thirty; patchy hair loss called alopecia areata, that may come and go; milk white spots on the skin called vitiligo; and a tendency to lose the ability to absorb vitamin B12 from your food causing (pernicious anemia).
Other immune disorders are also more common in these families, including Type I (juvenile) diabetes, rheumatoid arthritis, colitis, and lupus. For reasons we don't understand, these thyroid problems also seem linked with depression, carpal tunnel syndrome, and mitral valve prolapse. There is even some research suggesting that left-handedness or ambidexterity, and attention deficit hyperactivity disorder (ADHD) may be more common in these families. Problems with reading, writing, and difficulty with concentration may result.If you find you have a thyroid condition that often runs in families, it's worth considering whether some kind of thyroid disease or related condition are part of your close relatives' health problems too. The thyroid element is often missed in older people. And anyone close to you who is pregnant is also more likely to have thyroid problems during and after the pregnancy—again often overlooked.A curious difference between men and women with this genetic inheritance: women are 10 times more likely to get the family thyroid problems, while men more often have the associated left-handedness and ADHD.
Don't let your doctor skip your TSH test if you are over 50.