Gamma chain diseases, also referred to as gamma-globulin abnormalities or hereditary persistence of fetal hemoglobin (HPFH), are a group of inherited disorders that affect the structure and production of the gamma chains of hemoglobin. Hemoglobin is the protein responsible for carrying oxygen throughout the body.
A gamma chain disease arises due to a mutation in the genes that control the production of the gamma chains, resulting in altered or abnormal structure of these chains. This leads to an abnormal form of hemoglobin called fetal hemoglobin (HbF), which is normally present in utero but eventually decreases after birth. In individuals with gamma chain diseases, however, the production of HbF continues into adulthood.
There are several types of gamma chain diseases, including hereditary persistence of fetal hemoglobin type 1 (HPFH-1), hereditary persistence of fetal hemoglobin type 2 (HPFH-2), and delta-beta thalassemia. Each type is characterized by different genetic mutations and different levels of HbF expression.
Symptoms of gamma chain diseases can vary depending on the specific mutation and level of HbF production. Some individuals may be asymptomatic and only discovered to have the condition through blood tests, while others may experience mild to moderate symptoms such as anemia, jaundice, fatigue, and enlarged spleen.
Treatment for gamma chain diseases depends on the severity of symptoms and may include regular blood transfusions, iron chelation therapy, and managing complications such as infections or organ damage. Genetic counseling may also be recommended to help affected individuals understand the inheritance pattern and potential risks of passing the condition to their offspring.
