Turner Syndrome – Symptoms and Causes
Turner syndrome, a condition that only affects women, occurs when one of the X chromosomes (sex chromosomes) is missing or partially missing. Turner syndrome can cause a variety of medical and developmental problems, including short stature, lack of ovarian development, and heart defects.
Turner syndrome can be diagnosed prenatally (before birth), during infancy, or in infancy. Sometimes, in women with mild signs and symptoms of Turner syndrome, diagnosis is delayed until adolescence or young adulthood.
Girls and women with Turner syndrome need ongoing medical care from a variety of specialists. Regular checkups and proper care can help most girls and women lead healthy, independent lives.
The signs and symptoms of Turner syndrome can vary in girls and women with the condition. For some girls, the presence of Turner syndrome may not be obvious, but in other girls, several physical characteristics are apparent early on. Signs and symptoms can be subtle, developing slowly over time, or significant, like heart defects.
Turner syndrome may be suspected before birth based on prenatal cell-free DNA testing – a method of screening a developing baby for certain chromosomal abnormalities using a blood sample from the mother – or a prenatal ultrasound. An antenatal ultrasound of a baby with Turner syndrome may show:
- Large fluid collection on the back of the neck or other abnormal fluid collections (edema)
- Cardiac abnormalities
- Abnormal kidneys
At birth or during infancy
Signs of Turner syndrome at birth or during infancy may include:
- Wide or band-shaped collar
- low ears
- Broad chest with widely spaced nipples
- High and narrow roof of the mouth (palate)
- Arms that turn outward at the elbows
- Fingernails and toenails narrow and upturned
- Swelling of the hands and feet, especially at birth
- Slightly smaller than average size at birth
- Slowed growth
- heart defects
- Low hairline at the back of the head
- Receding or small lower jaw
- Short fingers and toes
In childhood, adolescence and adulthood
The most common signs in almost all girls, adolescents, and young women with Turner syndrome are short stature and ovarian failure due to ovarian failure. Failure of the ovaries to develop can occur at birth or gradually during childhood, adolescence, or early adulthood. Signs and symptoms of these include:
- Slowed growth
- No growth spurts at expected times in childhood
- Significantly lower adult height than would be expected for a female family member
- Failure to begin expected sexual changes during puberty
- Sexual development that “stalls” during adolescence
- Early end of menstrual cycles not due to pregnancy
- For most women with Turner syndrome, inability to conceive without fertility treatment
When to consult a doctor
Sometimes it is difficult to distinguish the signs and symptoms of Turner syndrome from other disorders. It is important to get a quick and accurate diagnosis and appropriate care. Consult your doctor if you have any concerns about the possibility of Turner syndrome. Your doctor may refer you to a doctor who specializes in genetics (geneticist) or hormonal disorders (endocrinologist) for further evaluation.
Most people are born with two sex chromosomes. Males inherit the X chromosome from their mother and the Y chromosome from their father. Females inherit one X chromosome from each parent. In women with Turner syndrome, one copy of the X chromosome is missing, partially missing, or changed.
Genetic changes in Turner syndrome can be any of the following:
- Monosomy. The complete absence of an X chromosome is usually due to an error in the father’s sperm or in the mother’s egg. As a result, each cell in the body has only one X chromosome.
- Mosaicism. In some cases, an error occurs in cell division during the early stages of fetal development. As a result, some cells in the body have two complete copies of the X chromosome. Other cells have only one copy of the X chromosome.
- X chromosome changes. Changed or missing parts of one of the X chromosomes can occur. Cells have a full copy and a modified copy. This error can occur in sperm or egg as all cells have one full copy and one modified copy. Or the error may occur in cell division early in fetal development so that only certain cells contain the changed or missing parts of one of the X chromosomes (mosaicism).
- Y chromosome material. In a small percentage of Turner syndrome cases, some cells have one copy of the X chromosome and other cells have one copy of the X chromosome and Y chromosome material. These individuals develop biologically as females, but the presence Y chromosome material increases the risk of developing a type of cancer called gonadoblastoma.
Effects of missing or altered chromosome
The missing or altered X chromosome in Turner syndrome causes problems during fetal development and other developmental problems after birth – for example, short stature, ovarian failure and heart defects. The physical characteristics and health complications that arise from these chromosomal problems vary widely.
The loss or alteration of the X chromosome occurs randomly. Sometimes it’s because of a problem with the sperm or egg, and other times the loss or damage to the X chromosome occurs early in fetal development.
Family history does not appear to be a risk factor, so parents of a child with Turner syndrome are unlikely to have another child with the condition.
Turner syndrome can affect the proper development of several bodily systems, but this varies greatly among people with the syndrome. Complications that may arise include:
- Heart problems. Many infants with Turner syndrome are born with heart defects or even mild heart structural abnormalities that increase their risk of serious complications. Heart defects often include problems with the aorta, the large blood vessel that branches from the heart and supplies oxygen-rich blood to the body.
- High blood pressure. Turner syndrome can increase the risk of high blood pressure, a condition that increases the risk of developing diseases of the heart and blood vessels.
- Hearing loss. Hearing loss is common with Turner syndrome. In some cases, this is due to the gradual loss of nerve function. An increased risk of frequent middle ear infections can also lead to hearing loss.
- Vision problems. An increased risk of poor muscle control of eye movements (strabismus), myopia, and other vision problems can occur with Turner syndrome.
- Kidney problems. Turner syndrome can be associated with malformations of the kidneys. Although these abnormalities don’t usually cause medical problems, they can increase the risk of urinary tract infections.
- Autoimmune disorders. Turner syndrome may increase the risk of an underactive thyroid (hypothyroidism) due to the autoimmune disease Hashimoto’s thyroiditis. There is also an increased risk of diabetes. Sometimes Turner syndrome is associated with gluten intolerance (celiac disease) or inflammatory bowel disease.
- Skeletal problems. Problems with growth and bone development increase the risk of abnormal curvature of the spine (scoliosis) and forward rounding of the upper back (kyphosis). Turner syndrome can also increase the risk of developing weak and brittle bones (osteoporosis).
- Learning disabilities. Girls and women with Turner syndrome usually have normal intelligence. However, there is an increased risk of learning disabilities, especially with learning that involves spatial concepts, math, memory, and attention.
- Mental health problems. Girls and women with Turner syndrome may have difficulty functioning in social situations, may experience anxiety and depression, and may be at increased risk for attention deficit/hyperactivity disorder (ADHD).
- Infertility. Most women with Turner syndrome are infertile. However, a very small number can get pregnant spontaneously, and some can get pregnant with fertility treatment.
- Pregnancy complications. Because women with Turner syndrome are at increased risk of complications during pregnancy, such as high blood pressure and aortic dissection, they should be evaluated by a cardiologist (cardiologist) and a high-risk pregnancy physician (maternal-fetal medicine specialist) before pregnancy. .
February 11, 2022