Thalassemia includes a number of different forms of anemia (red blood cell deficiency). The two main types are called alpha and beta thalassemias, depending on which part of an oxygen-carrying protein (called hemoglobin) is lacking in the red blood cells. The most severe form of alpha thalassemia, which affects mainly individuals of affects lacking in the red blood cells. The most severe form of alpha results in affects mainly individuals of Southeast Asian, Chinese and Filipino Southeast Asian, Chinese and Filipino ancestry, milder forms of the results in fetal or newborn death. Most individuals with alpha no effect on health.
milder forms of the disease, with varying degrees of anemia.  Individuals with no effect on health.beta thalassemias have variable symptoms ranging from very severe to having no effect on health.results in fetal or newborn death. Most individuals with alpha thalassemia have milder forms of the disease, with varying degrees of anemia.  Individuals with beta thalassemias have variable symptoms ranging from very severe to having no effect on health.

Thalassemia major, the most severe form, is also called Cooley's anemia, named after the doctor who first described it in 1925. Most children with t thalassemia major appear healthy at birth, but during the first year or two of life they become pale, listless and fussy, and have a poor appetite.  They grow slowly and often develop jaundice (yellowing of the skin).  Without treatment, the spleen, liver, and heart soon become greatly enlarged. Bones become thin and brittle; face bones become distorted, and children with thalassemia often look alike. Heart failure and infection are the leading causes of death among children with untreated thalassemia major.

Thalassemia intermedia is a mild Cooley's anemia. Children with thalassemia intermedia may develop some of the same complications, although in most cases, the course of the disease is mild for the first two decades of life.
 

Fragile X syndrome occurs in all racial and ethnic groups.  It is caused by an abnormality in a single gene of the "X" chromosome.  This is also one of the "sex" chromosomes (females have 2 X chromosomes while males have one X and one Y chromosome).  The mutation- (called FMR-1) - was discovered in 1991 and it can be tested for in families known to be at risk.  About one in 250 women in this country carries the fragile X gene. A woman is considered a carrier of fragile X syndrome if she has either a pre-mutation (60 to 200 trinucleotide repeats within her FMR-1 gene) or a full mutation (greater than 200 trinucleotide repeats within her FMR-1 gene). A carrier of a pre-mutation generally has no symptoms of fragile X syndrome, though recent studies suggest that women who carry this pre-mutation may be at increased risk of early menopause (prior to age 40). Approximately one-third to one-half of female carriers of a full mutation will exhibit signs of fragile X syndrome, but are usually less severely affected than males with full mutations.  Because the genetics of fragile X syndrome are complicated, a couple with a family history of fragile X syndrome should consult a medical geneticist or a genetic counselor to learn more about the risks of this disorder in their offspring.