WANI Dictionary

Poly-X syndrome

Also called the triple X syndrome, trisomy X, of trisomy 47. Poly X syndrome is a genetic disorder that affects about 1 in every 1,000 females. Instead of the female having two X chromosomes, the female has three X chromosomes.

Females with this condition tend to be taller than average females. Symptoms of this disease vary, but are in general not too severe. Most females have normal sexual development and are able to reproduce [2]. Symptoms include widely spaced eyes, flat feet, finger curvature (see images), seizures, premature ovarian failure or ovary abnormalities, and higher risk of learning desabilities.

There is no definitive treatment for this disease. Only symptomatic treatments are available, which include periodic screenings, early intervention services, educational assistance, and counseling.

Also see other chromosomal diseases: Down syndrome, Turner syndrome, and Klinefelter syndrome.

Definitions in the literature

• Triple X syndrome, also called trisomy X or 47,XXX, is a genetic disorder that affects about 1 in 1,000 females. Females normally have two X chromosomes in all cells — one X chromosome from each parent. In triple X syndrome, a female has three X chromosomes [1].
• Triple X syndrome, also called trisomy X or 47,XXX, is characterized by the presence of an additional X chromosome in each of a female's cells. Although females with this condition may be taller than average, this chromosomal change typically causes no unusual physical features. Most females with triple X syndrome have normal sexual development and are able to conceive children [2].