Distinctions Found Between Types of Hemoglobin H Disease
Outcomes may be worse with disease caused by hemoglobin H Constant Spring
WEDNESDAY, Feb. 23 (HealthDay News) -- Patients with hemoglobin H disease caused by hemoglobin H Constant Spring (HCS) appear to be at much higher risk for poor outcomes than those whose disease is caused by deletion of three out of four α-globin genes (HbH), according to research published in the Feb. 24 issue of the New England Journal of Medicine.
Ashutosh Lal, M.D., of the Children's Hospital and Research Center Oakland in California, and colleagues analyzed data on 86 patients with hemoglobin H disease to report on the natural history of the disease.
The researchers found hemoglobin H disease caused by HbH in 60 patients (70 percent) and by HCS in 23 (27 percent), with 3 (3 percent) caused by other, nondeletional forms of the disease. In patients with HbH, growth was normal during the first decade of life, but growth deficiencies started in infancy for those with HCS. HCS patients also experienced more severe anemia, with a probability of requiring an anemia-related blood transfusion before the age of 20 at 80 percent, compared with 3 percent in patients with HbH. Many patients with the disorders had mixed ethnic backgrounds.
"HCS should be recognized as a distinct thalassemia syndrome with a high risk of life-threatening anemia during febrile illnesses. HbH was not associated with an increased rate of severe anemia with infections and was managed without blood transfusions. Many patients with these disorders had mixed ethnic backgrounds, which highlights the need for extended newborn screening in populations that are traditionally considered to be at low risk for hemoglobin H disease," the authors write.