Autosomal recessive inheritance
Find information on thousands of medical conditions and prescription drugs.

Thalassemia minor

Thalassemia (American English) (or Thalassaemia in British English) is an inherited disease of the red blood cells, classified as a hemoglobinopathy. The genetic defect results in synthesis of an abnormal hemoglobin molecule. The blood cells are vulnerable to mechanical injury and die easily. To survive, many people with thalassaemia need blood transfusions at regular intervals. more...

Home
Diseases
A
B
C
D
E
F
G
H
I
J
K
L
M
N
O
P
Q
R
S
T
Candidiasis
Tachycardia
Taeniasis
Talipes equinovarus
TAR syndrome
Tardive dyskinesia
Tarsal tunnel syndrome
Tay syndrome ichthyosis
Tay-Sachs disease
Telangiectasia
Telangiectasia,...
TEN
Teratoma
Teratophobia
Testotoxicosis
Tetanus
Tetraploidy
Thalassemia
Thalassemia major
Thalassemia minor
Thalassophobia
Thanatophobia
Thoracic outlet syndrome
Thrombocytopenia
Thrombocytosis
Thrombotic...
Thymoma
Thyroid cancer
Tick paralysis
Tick-borne encephalitis
Tietz syndrome
Tinnitus
Todd's paralysis
Topophobia
Torticollis
Touraine-Solente-Golé...
Tourette syndrome
Toxic shock syndrome
Toxocariasis
Toxoplasmosis
Tracheoesophageal fistula
Trachoma
Transient...
Transient Global Amnesia
Transposition of great...
Transverse myelitis
Traumatophobia
Treacher Collins syndrome
Tremor hereditary essential
Trichinellosis
Trichinosis
Trichomoniasis
Trichotillomania
Tricuspid atresia
Trigeminal neuralgia
Trigger thumb
Trimethylaminuria
Triplo X Syndrome
Triploidy
Trisomy
Tropical sprue
Tropophobia
Trypanophobia
Tuberculosis
Tuberous Sclerosis
Tularemia
Tungiasis
Turcot syndrome
Turner's syndrome
Typhoid
Typhus
Tyrosinemia
U
V
W
X
Y
Z
Medicines

The disease's geographical association with the Mediterranean sea was responsible for its naming: Thalassa is Greek for the sea. Thalassemia occurs in all populations and ethnic groups, however the prevalence differs among different populations.

Read more at Wikipedia.org


[List your site here Free!]


Fetal hemoglobin test
From Gale Encyclopedia of Medicine, 4/6/01 by Janis O. Flores

Definition

Fetal hemoglobin (Hemoglobin F), Alkali-resistant hemoglobin, HBF (or Hb F), is the major hemoglobin component in the bloodstream of the fetus. After birth, it decreases rapidly until only traces are found in normal children and adults.

Purpose

The determination of fetal hemoglobin is an aid in evaluating low concentrations of hemoglobin in the blood (anemia), as well as the hereditary persistence of fetal hemoglobin, and a group of inherited disorders affecting hemoglobin, among which are the thalassemias and sickle cell anemia.

Description

At birth, the newborn's blood is comprised of 60%-90% of fetal hemoglobin. The fetal hemoglobin then rapidly decreases to 2% or less after the second to fourth years. By the time of adulthood, only traces (0.5% or less) are found in the bloodstream.

In some diseases associated with abnormal hemoglobin production (see Hemoglobinopathy, below), fetal hemoglobin may persist in larger amounts. When this occurs, the elevation raises the question of possible underlying disease.

For example, HBF can be found in higher levels in hereditary hemolytic anemias, in all types of leukemias, in pregnancy, diabetes, thyroid disease, and during anticonvulsant drug therapy. It may also reappear in adults when the bone marrow is overactive, as in the disorders of pernicious anemia, multiple myeloma, and metastatic cancer in the marrow. When HBF is increased after age four, it should be investigated for cause.

Hemoglobinopathy

Hemoglobin is the oxygen-carrying pigment found in red blood cells. It is a large molecule made in the bone marrow from two components, heme and globin.

Defects in hemoglobin production may be either genetic or acquired. The genetic defects are further subdivided into errors of heme production (porphyria), and those of globin production (known collectively as the hemoglobinopathies).

There are two categories of hemoglobinopathy. In the first category, abnormal globin chains give rise to abnormal hemoglobin molecules. In the second category, normal hemoglobin chains are produced but in abnormal amounts. An example of the first category is the disorder of sickle cell anemia, the inherited condition characterized by curved (sickle-shaped) red blood cells and chronic hemolytic anemia. Disorders in the second category are called the thalassemias, which are further divided into types according to which amino acid chain is affected (alpha or beta), and whether there is one defective gene (thalassemia minor) or two defective genes (thalassemia major).

Preparation

This test requires a blood sample. The patient is not required to be in a fasting state (nothing to eat or drink for a period of hours before the test).

Risks

Risks for this test are minimal, but may include slight bleeding from the blood-drawing site, fainting or feeling lightheaded after venipuncture, or hematoma (blood accumulating under the puncture site).

Normal results

Reference values vary from laboratory to laboratory but are generally found within the following ranges:

  • Six months to adult: up to 2% of the total hemoglobin.
  • Newborn to six months: up to 75% of the total hemoglobin.

Abnormal results

Greater than 2% of total hemoglobin is abnormal.

Key Terms

Anemia
A disorder characterized by a reduced blood level of hemoglobin, the oxygen-carrying pigment of blood.
Hemolytic anemia
A form of anemia caused by premature destruction of red cells in the blood stream (a process called hemolysis). Hemolytic anemias are classified according to whether the cause of the problem is inside the red blood cell (in which case it is usually an inherited condition), or outside the cell (usually acquired later in life).

Further Reading

For Your Information

    Books

  • Cahill, Mathew. Handbook of Diagnostic Tests. Springhouse Corporation, 1995.
  • Jacobs, David S. Laboratory Test Handbook. 4th ed. Lexi-Comp Inc., 1996.
  • Pagana, Kathleen Deska. Mosby's Manual of Diagnostic and Laboratory Tests. Mosby, Inc., 1998.

Gale Encyclopedia of Medicine. Gale Research, 1999.

Return to Thalassemia minor
Home Contact Resources Exchange Links ebay