John D. Chovan, James R. Cacchillo
Genetic Diseases, Iron Absorption, HFE Gene
Congenital, Hereditary, and Neonatal Diseases and Abnormalities | Medical Pathology | Medicine and Health Sciences | Nursing
One of the most common genetic diseases, hereditary hemochromatosis is a disruption of iron regulation in the body. Its geographic distribution is worldwide, but it is most common in those of northern European origin. (Roach and Di Palma, 2012). Occurrence is rare in other racial or ethnic groups. (Emanuele, Tuason, & Edwards, 2014). Symptoms are due to significant iron overload, normally as a result of HFE gene mutation. (Centers for Disease Control and Prevention, 2010). The HFE gene plays an important role in regulating iron absorption in the GI tract, transport, and storage. (Emanuele, et al., 2014). If excess iron accumulates in vital organs, cirrhosis, bone and joint disease, diabetes, other endocrine disorders and heart disease can result. (Crownover & Covey, 2013). Although penetrance (exhibition of phenotype, or clinical symptoms) varies in those with the genetic mutation, those who have the HFE mutation are much more genetically susceptible to iron overload as it manifests in hereditary hemochromatosis. Patients can present with nonspecific complaints such as weakness, fatigue, changes in mental status, and arthralgia, so hereditary hemochromatosis can be missed or misdiagnosed if iron study testing is not performed. The most common route to diagnosis is through routine office visits or investiation of common complaints. (Brissot, Ball, Rofail, Cannon, & We Jin, 2011). In some cases, but not all, genetic testing may be appropriate. Other forms of iron overload must be considered as well when making a differential diagnosis. Hereditary hemochromatosis has an autosomal recessive pattern; a carrier father and carrier mother have a 1 in 4 chance of having a homozygous child and a 50% chance of having a heterozygous (carrier) child. About 75% of homozygotes have expression of the disease with elevated serum ferritin levels, although there is some controversy as to the proportion which develops clinically significant disease. Environmental and genetic factors may interact to influence expression of hereditary hemochromatosis.(Roach & DiPalma,2012). Approximately 1 million people in the United States are homozygous for the mutation. (National Heart Lung and Blood Institute, 2011). According to Emauele, et al., (2014), 1 in 8 to 1 in 10 whites in the United States may be carriers of the affected HFE gene.
Davidson, Kari, "Understanding Hereditary Hemochromatosis" (2015). Master of Science in Nursing (MSN) Student Scholarship. 93.