Dear Doctor Column, September 6, 2004

Thalassemia is Inherited Disease

Question:

I have read that thalassemia is a hereditary disease and is transmitted through parents. But, can one partner who has it transmit it to another through intercourse?

Answer:

No. Thalassemia cannot be transmitted through casual or sexual contact. The thalassemias are a group of genetic (inherited) blood disorders that affect a person's ability to produce hemoglobin — the protein in red blood cells that carries oxygen and nutrients throughout the body. Both parents must have the thalassemia trait in their genetic code in order to pass the disease to their children, but it only takes one parent to pass the trait to a child.

The thalassemias are divided into two main types: alpha thalassemia and beta thalassemia. Within each type, there are three classifications: thalassemia minor (or trait), thalassemia intermedia, and thalassemia major (disease). Sometimes, Cooley's anemia, named after the physician who described it, is used to describe beta thalassemia major. Hydrops fetalis is the other name for alpha thalassemia major.

A person with thalassemia minor will experience no significant health problems, except possibly a mild anemia that does not respond to iron supplements. Thalassemia intermedia is an intermediate form of the disease requiring regular health care. Thalassemia major is a serious disease requiring regular blood transfusions and extensive medical care.

A child with hydrops fetalis may die in utero. Other children with thalassemia major, unless it is treated, can experience several or all of the following signs and symptoms: severe anemia, jaundice, an enlarged spleen, fatigue, listlessness, reduced appetite, enlarged and fragile bones, facial malformation, growth problems, and increased susceptibility to infection. Without treatment, oxygen and nutrients cannot get to the body's tissues and organs, leaving them unable to function properly. In parts of the world where blood for transfusion is not readily available, many children die of severe thalassemic anemia. However, those who receive regular transfusions and undergo iron removal therapy can avoid many of these symptoms.

Descendants from Southeast Asia, southern China, the Middle East, the Mediterranean (Greece, Italy, Turkey), parts of North Africa, and parts of the Pacific Islands are at an increased risk for thalassemia. In fact, thalassemia is the most common inherited single gene disorder in the world; boys and girls are equally affected.

Because individuals with thalassemia major cannot produce enough hemoglobin to survive, they need a blood transfusion every 3 to 4 weeks in order to grow and live normally. However, there are risks associated with chronic blood transfusion, including exposure to blood-borne infections, transfusion reactions, such as fever or rash, and alloimmunization, which occurs when a person who has repeated blood transfusions develops antibodies against the donated blood that can cause serious reactions.

The greatest problem associated with chronic transfusion is iron overload. Since the body has no way of ridding itself of excess iron, iron begins to deposit in the body's organs, especially the heart, liver, and pituitary gland. It also affects normal development and bone growth. Chronically transfused patients must take a nightly infusion of deferoxamine (Desferal) to remove the excess iron.

Currently, the only cure for thalassemia is a bone marrow transplant, which also carries significant risk. A recent development in transplantation involves using blood from the umbilical cord from a newborn baby. Transplants that use umbilical cord blood generally have fewer complications than cells collected from a similar adult donor. Gene therapy also is being explored.

A blood test can determine if you have thalassemia trait. If you're thinking of having a child, you might want to consult a genetic counselor.

For more information, visit Cooley's Anemia Foundation www.cooleysanemia.org; U.S. Department of Health and Human Services www.health.gov and www.healthfinder.gov; and the March of Dimes www.modimes.org.