Turner syndrome is a chromosomal abnormality affecting growth and development in females. Approximately one in 2,500 females worldwide are affected by Turner syndrome. The condition most prevalently affects fetuses from pregnancies that end in miscarriage or stillbirth.
Definition & Facts
The condition is named after Dr. Henry Turner, who was the first doctor to report on the disorder in 1938. Females normally have two X chromosomes. Turner syndrome occurs when one of the X chromosomes is either partially or completely missing.
The chromosomal abnormality occurs randomly and may be the result of a problem with the egg or sperm. The X chromosome may also be lost or damaged during the fetal development process. The disorder does not appear to run in families, and parents of a child with Turner syndrome are not at increased risk of having a second child with the condition.
Symptoms & Complaints
- Swelling of the hands and feet
- Webbed neck
- Low-set ears
- A high, narrow palate
- Low hairline at the base of the neck
- Short toes and fingers
- Arms that turn slightly outward at the elbows
- Barrel-shaped chest with wide nipples
- Slightly shorter than average height at birth
- Narrow, upturned finger, and toenails
- Vision problems
- Skeletal disorders
- Frequent ear infections
- Heart and kidney abnormalities
As the female gets older, the short stature becomes more pronounced. Most people with Turner syndrome tend to be approximately eight inches shorter than other female members of their family. Individuals with Turner syndrome do not experience the normal adolescent growth spurt or the sexual development that accompanies puberty.
Most people with the condition do not have regular menstrual cycles and are infertile. Those with the disorder are of normal intelligence but may experience learning difficulties, particularly in the areas of math and spatial reasoning. Individuals with Turner syndrome may also have some difficulties in social situations, such as reading and interpreting other people’s emotions and actions.
Turner syndrome is the result of a genetic abnormality involving the X chromosome; however, it is not clear what causes the defect to occur. There are several variations of Turner syndrome depending on the exact nature of the anomaly. Monosomy involves the complete absence of the X chromosome. Each cell in the body only has one X chromosome. This typically occurs due to an error in the mother’s egg or the father’s sperm.
Mosaic Turner syndrome occurs when some cells have two complete copies of the X chromosome while others only have one copy or have one complete copy and one partial copy. Mosaic Turner syndrome is the result of an error in cell division during fetal development.
In very rare cases, some cells have one copy of the X chromosome and others have an X chromosome as well as some Y chromosome material. While genetically female, these individuals do have an increased risk of a cancer known as gonadoblastoma.
Diagnosis & Tests
Abnormalities during a prenatal ultrasound may lead a doctor to suspect Turner syndrome. The diagnosis is confirmed by amniocentesis or chorionic villus sampling. These procedures obtain samples of amniotic fluid or placental tissue that are submitted for chromosomal analysis.
Diagnosis is often made at birth due to the presence of heart problems and swelling of the hands and feet. In some cases, the diagnosis is not made until the patient is slightly older and does not follow normal growth patterns or go through puberty as expected.
Treatment & Therapy
It is important that those with Turner syndrome receive care from a team of pediatric specialists as soon as possible after diagnosis to screen for developmental and medical complications. The makeup of the team may change depending on the needs of the child and may include:
- Heart specialists
- ENT specialists
- Mental health professionals
- Education specialists trained in learning disabilities
- Optometrists or ophthalmologists
Most people with Turner syndrome benefit from growth hormone treatment during childhood and early teens. This will help them achieve as much height as possible. Growth hormone treatment involves regular injections of somatropin. In some cases, the doctor may also recommend an androgen known as oxandrolone in conjunction with the growth hormone.
Most patients with the condition require life-long hormone therapy. Estrogen hormone therapy typically begins at the normal age of puberty and continues to the normal age of menopause. The hormones aid in growth and sexual development.
Other treatments depend on the exact nature of the patient’s symptoms and complications. For example, surgery may be necessary to correct specific heart abnormalities. It is possible for some women with Turner syndrome to become pregnant with the help of a specially tailored hormone therapy and donor embryos. These pregnancies are considered high-risk and should be monitored carefully by an OB/GYN familiar with the condition.
Women with Turner syndrome are more likely to experience high blood pressure, diabetes, osteoporosis, hypothyroidism, vision problems, and hearing loss later in life. They should be encouraged to have regular health maintenance visits for preventative care and treatment of these conditions as they may arise later in life.
Prevention & Prophylaxis
Maintaining a healthy weight and healthy lifestyle habits are important to prevent obesity, high blood pressure, and diabetes. Parents of people with Turner syndrome should encourage their child to develop a social support network to help build self-esteem and self-worth. The Turner Society of the United States is a valuable resource for information for parents and individuals living with Turner syndrome.