Triple X Syndrome

Tracie Emmerich Professor Debbie Seale Biology 101 TR, 8:30-11:30 am 3/6/2012 Triple X Syndrome Triple X Syndrome is a sex chromosome abnormality in which there are three X chromosomes instead of the usual two found in most females. Triple X Syndrome is also known as Trisomy X, Triplo X Syndrome, and XXX Syndrome. The first published report of a woman with a karyotype with a 47, XXX was by Patricia A. Jacobs in 1959 at a hospital in Scotland. Most people have 46 chromosomes, occurring in 23 pairs. These chromosomes contain genes, which carry instructions that determine everything from your height to your eye color.One of these chromosome pairs determines your sex. You receive one sex chromosome from your mother and another from your father. Your mother can give you only an X chromosome, but your father can pass on an X or a Y chromosome. If you receive an X chromosome from your father, the XX pair makes you genetically a female. Females with Triple X syndrome have a third X chromosom e. Triple X syndrome usually results from an error in the formation of a mother's egg cell or a father's sperm cell. Sometimes, triple X syndrome occurs as a result of an error early in the embryo's development.Although this condition is genetic, it's typically not inherited. Instead, what usually happens is that either the mother's egg cell or the father's sperm cell has not formed correctly, resulting in an extra X chromosome. This random error in egg or sperm cell division is called nondisjunction. Nondisjunction is a random event and is not caused by anything either of the baby’s parents did or by any medications they may have taken. When the cause is a malformed egg cell or sperm cell, as is usually the case, all the body's cells have the extra chromosome.In the mosaic form, only some of the body's cells have the third X chromosome. Because only some cells contain the extra X chromosome, females with the mosaic form of triple X syndrome may have less severe symptoms. Tri ple X Syndrome occurs in about 1 out of every 1,000 girls born in the United States. It is estimated that between five and ten girls are born with the condition each day. As far as it is known, the syndrome is equally common in all racial and ethnic groups. The only known risk factor is the mother’s age.Women who are 35 years old or older when they become pregnant are at an increased risk of having a daughter with Triple X Syndrome. Because of the lyonization, (the process by which or the condition in which all X chromosomes of the cells in excess of one are inactivated on a random basis )inactivation and formation of a Barr body, in all female cells, only one X chromosome is active at any time. Thus, Triple X syndrome most often causes no unusual physical features or medical problems. If symptoms do appear, they may include: 1. Tall stature: Taller than other girls and women in the family 2.Small head (microcephaly) Microcephaly is a medical condition in which the circumfere nce of the head is smaller than normal because the brain has not developed properly or has stopped growing. Microcephaly can be present at birth or it may develop in the first few years of life. 3. Slightly lower weight at birth 4. Epicanthal folds: An epicanthal fold is skin of the upper eyelid — from the nose to the inner side of the eyebrow — that covers the inner corner (canthus) of the eye 5. Delayed development of certain motor skills, speech and language 6.Although rarely exhibiting severe mental impairments, Triple X Syndrome females have an increased risk of learning disabilities such as dyslexia, delayed speech, deficient language skills and delayed development of motor skills. It is possible that learning disabilities and/or delayed development could eventually lead to a variety of other issues, including academic problems, stress, and poor socialization skills that cause social isolation. 7. Weak muscle tone and delayed motor skills: poor coordination, awkw ardness 8. Menstrual irregularities 9. Increased rick of depression 10. Less assertive and quieter than most girls 1. Intelligence (IQ) may be slightly lower than that of other girls and women in the family although mental retardation is unusual. 10-15 points below siblings. Other possible, though much rarer, complications that may occur include: 1. Premature ovarian failure or ovary abnormalities. When the ovaries stop working before the expected age of menopause, there's a decline in the production of certain hormones and eggs are no longer released by the ovaries each month. This can cause infertility. Additionally, girls and women with triple X syndrome may have malformed ovaries. 2. Seizures.Girls and women with triple X syndrome may develop a seizure disorder. 3. Kidney abnormalities. Females born with triple X syndrome may also have abnormally developed kidneys or may have only one kidney. â€Å"There are even rare cases when a female with Triple X syndrome is affected by ch anges such as behavioral problems, midfacial hypoplasia, wide-set eyes, amenorrhea, posteriorly rotated ears, small head, long head, small lower jaw, expressionless face, prominent forehead, enamel hypoplasia, widely spaced nipples, small hands, small feet, kyphosis, lordosis, reduced muscle tone, and mental retardation. There are seldom any observable physical anomalies in Triple X females, other than being taller than average. Most women with Triple X have normal sexual development. Some experience an early onset of menstruation. Triple X women are rarely diagnosed, apart from pre-natal testing methods, unless they undergo amniocentesis and blood tests for medical reasons later in life. Most medical professionals do not regard the condition as a disability.However, if mild delays are present, such status can be sought by parents for early intervention treatment The chromosome change that causes triple X syndrome cannot be repaired, so the syndrome itself has no cure. Also because it is thought to be caused by a by a spontaneous genetic mutation rather than an inherited genetic defect, there is no way to prevent it. However, given the treatable nature of most symptoms and how frequently no symptoms appear at all, it's quite possible to lead a full and normal life despite having this syndrome.Because people with triple X syndrome may be more susceptible to stress, it's important to make sure a female with Triple X Syndrome has a supportive environment as well. Psychological counseling may help, both by teaching their families useful methods of demonstrating love and encouragement, and by discouraging behaviors that they might not realize are negative. According to a Danish researcher who started one of the first Triple X Syndrome support groups in the world, â€Å"If the conditions are good, stable, and stimulating†¦. learning problems rarely have any serious consequences.However, most Triple X girls need remedial teaching at school at one time or anothe r, and it is important they get this help if and when they need it. † The prognosis for girls with this syndrome is generally good. They are not at increased risks of other diseases as far as it is known and have a normal life expectancy. They are less likely to complete college than other girls, but almost all can finish high school with speech therapy or other additional help. While a few may have some social difficulties,. most are able to join the work force, marry, and start families in adult life.