Turner Syndrome Facts For Patients And Parents
Turner syndrome or gonadal dysgenesis is a genetic condition that affects only women.
It causes developmental abnormalities and medical problems after
birth including a short stature, failure to begin puberty, infertility,
heart defects and certain learning disabilities.
multiple abnormalities, careful medical follow-up can allow these women
to live relatively healthy and independent lives. Therefore it is quite
important for the patient and carers to understand the condition to
allow optimal medical care and follow-up.
In the US and worldwide,
the frequency of Turner syndrome is approximately 1 in 2000 live-born
female infants. As many as 15% of miscarriages are due to Turner
In this article, I will present in a simple and
easy to comprehend format the necessary Turner syndrome facts you need
to know, either as a parent or someone with the disease.
Genetic Causes And Risk Factors
Human development in the uterus during pregnancy as well as the
structure and function of the body after birth are determined by genes.
This is similar to a computer program which determines what size the
letters of this page will be as well as the color etc though you do not
see the program itself. This is the way genes function.
the genes are contained with the nucleus in long microscopic threadlike
materials called chromosomes.Humans have 46 chromosomes in each body
cells, arranged in 23 pairs. The genes which control sexual development
leading to a boy or girl during early pregnancy are found in two
chromosomes, called X and Y. Each child gets one type from each parent.
The Y chromosome contains the genes that will make a fetus develop to a
boy.A normal female will have two chromosomes, all X and written as XX.
She gets one X from the mother and the other X from the father. A
normal male will have two chromosomes, one X and the other Y and
written as XY. He gets the X from the mother and the Y from the father.
Abnormal genes in Turner.Turner
syndrome occurs when a child has only one X chromosome, written as XO.
The “O” meaning the second chromosome is missing. Since the X present
leads to the development of a female sexual make up, the fetus will
develop to a female. The genetic make up is written as 45,XO. The 45
means there are 45 chromosomes instead of the normal 46 while the XO
means there is only one X chromosome and a missing second chromosome.
A normal female is 46, XX which shows the correct number of chromosomes
46 and the two X chromosomes.
To go a bit further, there are three main ways that may lead to this absent X chromosome
” Mono-” means one. Only one sex chromosome is found instead of two.
It occurs when the father’s sperm or mother’s egg had a problem.
Normally, before a sperm cell is produced, a cell having two sex
chromosomes such as XX divides in two and each daughter cell takes one
of the two sex chromosomes. If one daughter cells refuses to
share for whatever reason, it then takes the two chromosomes and the
other daughter cells is left with none. If this daughter cell, which
had nothing gets fertilized, the fetus will not have the normal two sex
chromosomes but one, leading to monosomy X. In about two-thirds of
cases, the paternal chromosome is what is missing.
This is another mechanism where the cells have different amounts of
chromosome in the body. Normally, almost all cells of the body have the
same amount of chromosomes. Mosaicism occurs when cells have different
amount of chromosomes. This is one possible mechanism that also leads to
- Y chromosome material.
In a small percentage of cases of Turner syndrome, some cells have one
copy of the X chromosome while other cells have one copy of the X
chromosome and some Y chromosome material. The Y chromosome material is
not a full Y chromosome and increases the risk of some types of cancers.
No clear risk
factors have been identified. It is a process that occurs primarily by
chance. Having one child with the disease does not make the parents more
likely to have another child with the same disease.
There are many possible symptoms. Since it is a genetic disorder, the
manifestation of the disease begins from birth. They can encompass
physical, sexual or behavioral development.
At birth or during infancy
Common findings include
- Wide or web-like neck. Often very characteristic
- Receding or small lower jaw and high, narrow roof of the mouth (palate)
- Low-set ears, low hairline at the back of the head and drooping eyelids
- Broad chest with widely spaced nipples
- Short fingers and toes with arms that turn outward at the elbows (cubitus valgus)
- Swelling of the hands and feet, especially at birth and fingernails turned upward
- Slightly smaller than average height at birth
- Delayed growth
- Sensitivity to noise
In older girls, adolescents and young women
Some girls have only few symptoms suggestive of Turner syndrome which may not be easily identified.
Common findings include
- Growth failure in childhood leading to short stature, with an adult height of about 8 inches (20 centimeters).
- Learning disabilities with intelligence usually normal.
- Difficulty in social situations, such as problems understanding other people’s emotions or reactions
- Failure to begin sexual changes expected during puberty or an arrest of development.
- Early end to menstrual cycles not due to pregnancy
The genetic abnormality usually affects the development of many organs and body systems. Some include
- Cardiac malformations. This
may be seen in about one third of girls with Turner syndrome. It
includes malformations of the main blood vessel leaving the heart(
aorta) increasing the risk of a tear( aortic dissection) or narrowing
of the valve (aortic valve stenosis).Patients also have an increased risk of high blood pressure and diabetes which in turn increase the risk of heart disease.
- Hearing loss. This is a common complication. It often results from problems with the
nerves of the ear or sometimes due to the little bones in the ear. There is also an increased risk of ear infections which may latter contribute to the hearing loss.
- Kidney malformations. About a third of women with this Turner syndrome have abnormal
development of the kidneys. Sometimes, the right and left kidneys fuse
to form one huge kidney called the horseshoe kidney. The kidney and
urinary tubes in many such cases work well but can easily get infected.
- Autoimmune disorders. There is
an increased risk of autoimmune disease involving the thyroid (
reduced function or hypothyroidism), celiac disease of the intestines
leading to wheat intolerance and also Type 1 diabetes.
- Dental problems. Tooth and jaw bone development may be abnormal in Turner syndrome
leading to poorly aligned teeth, easy tooth loss and areas of sparse
and crowded teeth.
- Vision problems.This often includes misaligned eyes( or squint) and inability to see close objects( hypermetropia).
- Musculo-skeletal problems. This
syndrome can affect the spine, leading to abnormal curvature(
scoliosis) or forward rounding of the upper back (kyphosis). There is an
increased risk of bone loss leading to osteoporosis.
- Infertility and pregnancy complications.With appropriate medical care, pregnancy is possible for some women with Turner syndrome. Such pregnancies however, are often high risk pregnancies and need close medical follow-up.
- Psychological issues. Turner syndrome may bring an emotional stress on the girl and the
family. Affected girls and women may have an increased risk of low
self-esteem, depression, anxiety, difficulties functioning well in
social situations and attention-deficit/hyperactivity disorder.
The diagnosis of Turner syndrome may be made either before or after birth.
is diagnosis made during fetal development. The suspicion of Turner
syndrome is often raised following an obstetrical ultrasound which
identifies some developmental abnormalities suggestive of Turner
syndrome. To confirm the diagnosis, one of the following two procedures
could be done
- Chorionic villus sampling. A piece of placental tissue is obtained for analysis.
- Amniocentesis. The amniotic fluid is used for analysis.
doctor will often discuss with the parent to arrive at the best
option, considering the risks and benefits for each procedure.
Diagnosis after birth
possibility of Turner’s syndrome can be raised by the parents following
identification of abnormal physical or developmental features. The
doctor often conducts the clinical examination and request for genetic
analysis using what is called the Karyotype. The karyotype then
identifies a missing chromosome and confirms the diagnosis in most
Screening for associated abnormalities
the diagnosis is confirmed, a multiple specialty doctors like
cardiologists, dentists, nephrologists etc will be required to screen
and subsequently treat any associated malformations as discussed under
complications above. Therefore many other lab and imagine tests might be
necessary to search for possible abnormalities.
Turner syndrome is a life-long condition. At the moment, there is no
cure for the condition but effective treatments are available for most
of the common abnormalities of the syndrome which can lead to a healthy
The major component of treatment is the use of hormones to supplement the hormonal deficit.
- Growth hormone.
This is especially important for children. Its purpose is to aid growth
in height to attain a normal or near-normal height. These hormones
are often given as injections.
- Estrogen therapy.
Estrogen is necessary for puberty to occur and also to maintain normal
adult sexual development and function. These hormones will be taken
throughout the normal reproductive age of women until the age of
Pregnancy and fertility treatment
small number of women with Turner syndrome can successfully achieve a
pregnancy without medical treatment. However, because of the structural
and functional abnormalities in the ovaries, most of such women will end
up having failure of the ovaries early in adulthood.
Reproductive technologies now allow women to achieve a pregnancy with techniques like egg donation.
the case, close follow-up with the gynecologist is required for
conception and also during antenatal period because such pregnancies are
considered high risk pregnancies.
This is an important part of the treatment. It is lifelong and involves multiple specialists.
, the primary doctor will help coordinate the patients care to
appropriate follow up for teeth, heart, kidney, autoimmune or other
It is important both the parent and the girl be
prepared for this during childhood. AS the girl transitions to adult
care, she will no longer be seen by her pediatrician and will often need
to follow-up her care as an adult.
Girls may be faced with difficulties coping especially with her
peers because of their physical features. Though this difficulties also
challenge the parents to some degree, they are the first and immediate
support system for the daughter.
The Turner Syndrome Society of
the United States and other organizations provide educational materials,
resources for families and information about support groups. The
website is www.turnersyndrome.org
The good news is that most woman can lead active healthy lives with appropriate medical follow-up.
Turner syndrome does not cause mental retardation.
Some expected limitations include
- Slightly shorter stature than average even with the use of growth hormones.
Life expectancy is slightly shorter than average but may be improved
by attention to associated chronic illnesses, such as obesity and
- Almost all individuals are infertile, but pregnancy with donor embryos is possible.
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