Turner syndrome is caused by the deletion of part or all of one of the two X chromosomes.
Girls with the syndrome are typically short and with loose skin on the back of the neck, learning disabilities, and an inability to undergo puberty.
The diagnosis is confirmed by analyzing the chromosomes.
Treatment with hormones can stimulate growth and initiate puberty.
Chromosomes Chromosomes Genes are segments of deoxyribonucleic acid (DNA) that contain the code for a specific protein that functions in one or more types of cells in the body or the code for functional ribonucleic... read more are structures within cells that contain DNA DNA Genes are segments of deoxyribonucleic acid (DNA) that contain the code for a specific protein that functions in one or more types of cells in the body or the code for functional ribonucleic... read more and many genes. Genes are segments of deoxyribonucleic acid (DNA) and contain the code for a specific protein that functions in one or more types of cells in the body. Genes contain instructions that determine how the body is supposed to look and function. (See Genes and Chromosomes Genes and Chromosomes Genes are segments of deoxyribonucleic acid (DNA) that contain the code for a specific protein that functions in one or more types of cells in the body or the code for functional ribonucleic... read more for a discussion about genetics.)
The sex chromosomes Sex chromosomes Genes are segments of deoxyribonucleic acid (DNA) that contain the code for a specific protein that functions in one or more types of cells in the body or the code for functional ribonucleic... read more determine whether a fetus becomes male or female. A pair of X and Y chromosomes (XY) results in a male, and a pair of X and X chromosomes (XX) results in a female.
Worldwide, Turner syndrome occurs in about 1 out of 2,500 live female births. Almost all affected fetuses miscarry spontaneously.
Symptoms of Turner Syndrome
Some symptoms of Turner syndrome are noticeable at birth. Other symptoms are not noticed until the children are school-age or older.
Many newborns with Turner syndrome are mildly affected, but some have swelling (lymphedema Lymphedema Lymphedema is the accumulation of lymph in tissues, resulting in swelling. When lymphatic vessels are injured or obstructed, lymph fluid cannot drain and accumulates in tissues, causing swelling... read more ) on the backs of their hands and tops of their feet. Swelling or loose folds of skin are often evident over the back of the neck.
Heart defects include narrowing of part of the aorta (coarctation of the aorta Coarctation of the Aorta Coarctation of the aorta is a narrowing of part of the aorta, the main blood vessel bringing red oxygenated blood from the heart to the body. The aorta narrows, causing the heart to pump harder... read more ).
Other common abnormalities seen later include a webbed neck (wide skin attachment between the neck and shoulders) and a broad chest with widely spaced and inwardly turned nipples.
Infants are at a higher risk of a problem with the hip joint called developmental dysplasia of the hip Developmental Dysplasia of the Hip Developmental dysplasia of the hip is a birth defect in which the bones in the hip are incorrectly developed. Birth defects, also called congenital anomalies, are physical abnormalities that... read more .
Less common symptoms include drooping upper eyelids (ptosis), a low hairline at the back of the neck, moles Moles Moles are small, usually dark, skin growths that develop from pigment-producing cells in the skin (melanocytes). Most people have some moles, but the tendency to develop atypical moles is sometimes... read more (nevi), and poorly developed nails.
Older children, adolescents, and women
In most girls, the ovaries are replaced by connective tissue and do not contain developing eggs (gonadal dysgenesis), so these girls are infertile. Gonadal dysgenesis causes a lack of menstrual periods (amenorrhea Absence of Menstrual Periods Having no menstrual periods is called amenorrhea. Amenorrhea is normal in the following circumstances: Before puberty During pregnancy While breastfeeding read more ) and breast development. Girls may not go through the changes of puberty or may not complete puberty. A small number of girls do have a normal puberty and reproductive function.
About 10% of adolescents have scoliosis Scoliosis Scoliosis is abnormal curvature of the spine. Scoliosis can be present at birth or can develop during adolescence. Mild forms may cause only mild discomfort, but more severe forms can cause... read more .
Other problems may develop. High blood pressure High Blood Pressure High blood pressure (hypertension) is persistently high pressure in the arteries. Often no cause for high blood pressure can be identified, but sometimes it occurs as a result of an underlying... read more frequently occurs even if the girl does not have coarctation of the aorta. Kidney defects are common.
Occasionally, abnormal blood vessels in the intestine cause bleeding. Hearing loss Hearing Impairment in Children Hearing impairment refers to any degree of hearing loss, mild to severe, and can occur when there is a problem with a part of the ear, including the inner, middle, and outer ears, or the nerves... read more may occur, and crossed eyes (strabismus Strabismus Strabismus is an intermittent or constant misalignment of an eye so that its line of vision is not pointed at the same object as the other eye. If untreated, strabismus can cause amblyopia ... read more ) and farsightedness (hyperopia) are common.
Celiac disease Celiac Disease Celiac disease is a hereditary intolerance to gluten (a protein found in wheat, barley, and rye) that causes characteristic changes in the lining of the small intestine, resulting in malabsorption... read more , inflammation of the thyroid gland, and diabetes mellitus Diabetes Mellitus (DM) in Children and Adolescents Diabetes mellitus is a disorder in which blood sugar (glucose) levels are abnormally high because the body does not produce enough insulin or fails to respond normally to the insulin produced... read more occur more frequently among girls with Turner syndrome compared to the general population.
Girls with Turner syndrome caused by a certain type of chromosome abnormality are at increased risk of a tumor of the ovaries called gonadoblastoma, which may be cancerous (malignant).
Many girls with Turner syndrome have attention-deficit/hyperactivity disorder Attention-Deficit/Hyperactivity Disorder (ADHD) Attention-deficit/hyperactivity disorder (ADHD) is poor or short attention span and/or excessive activity and impulsiveness inappropriate for the child’s age that interferes with functioning... read more and learning disabilities Learning Disorders Learning disorders involve an inability to acquire, retain, or broadly use specific skills or information, resulting from deficiencies in attention, memory, or reasoning and affecting academic... read more with difficulty assessing visual and spatial relationships, planning tasks, and paying attention. They tend to score poorly on certain performance tests and in mathematics, even if they achieve average or above-average scores on verbal intelligence tests. Intellectual disability is rare.
A girl or woman with Turner syndrome is often short compared with family members, and obesity is common.
Diagnosis of Turner Syndrome
Appearance at birth
Doctors may suspect the diagnosis of Turner syndrome if a newborn has lymphedema or a webbed neck. However, they may not suspect the syndrome until adolescence, when the girl is short and has delayed puberty Delayed Puberty Delayed puberty is defined as absence of the start of sexual maturation at the expected time. Most often, children simply develop later than their peers but ultimately develop normally. Sometimes... read more with no periods.
To confirm the diagnosis, doctors do a blood test to analyze the chromosomes.
Doctors do echocardiography Echocardiography and Other Ultrasound Procedures Ultrasonography is a type of medical imaging that uses high-frequency (ultrasound) waves to produce a moving image of internal organs and other tissues. Echocardiography is ultrasonography of... read more or magnetic resonance imaging Magnetic Resonance Imaging (MRI) of the Heart Magnetic resonance imaging (MRI) is a type of medical imaging that uses a strong magnetic field and very high frequency radio waves to produce highly detailed images, including of the heart... read more (MRI) of the heart to detect heart problems and continue to screen for them regularly.
Treatment of Turner Syndrome
Surgical repair of heart defects
Growth hormone therapy
Regular evaluations for other problems
There is no cure for Turner syndrome. However, some specific symptoms and problems caused by the syndrome can be treated.
Coarctation of the aorta is usually repaired surgically. Doctors monitor and repair other heart defects as needed.
Lymphedema can usually be controlled with support hosiery and other techniques such as massage.
Treatment with growth hormone can stimulate growth. Once satisfactory growth has been achieved, treatment with growth hormone is stopped.
Treatment with the female hormone estrogen is usually needed to initiate puberty Puberty in Girls Puberty is a sequence of events in which physical changes occur, resulting in adult physical characteristics and capacity to reproduce. These physical changes are regulated by changes in the... read more and is typically given at age 12 to 13 but is usually not started until after satisfactory growth has been achieved. After girls have undergone puberty, they are given birth control pills that contain estrogen and progestin. These medications help girls maintain their female sexual characteristics. Estrogen therapy may also improve the girl’s ability to plan tasks, pay attention, and assess visual and spatial relationships and also helps the bones become dense and helps the skeleton develop properly.
Some girls who have Turner syndrome begin puberty normally without estrogen therapy, but this is more common among girls who are mosaic. Girls who have mosaic Turner syndrome have a mixture of two or more types of cells. Some of their cells contain two or more X chromosomes and some cells contain just one X chromosome. These people with Turner syndrome may become pregnant, and they should use contraception if they are sexually active and want to prevent pregnancy. Fertility may be limited, so if they wish to become pregnant, they usually require alternative fertility interventions.
Girls with Turner syndrome should have regular evaluations to detect problems that may result from this disorder. Evaluations include the following:
Kidney function tests
Bone evaluations (for hip dislocations and scoliosis)
Eye examinations by a pediatric ophthalmologist
Thyroid function tests
Screening tests for celiac disease
Blood tests for glucose (sugar) intolerance (starting at 10 years of age)