What is Turner Syndrome?
Turner syndrome is one of the chromosomal conditions which affects only females and males are not affected mostly by this condition.
It is considered as one of the genetic disorders which occurs due to the partial or complete loss of one of the X chromosomes.
It is also referred to as monosomy of X.
This condition leads to various developmental abnormalities and they are also suspected to many diseases.
It was first observed by Henry. H. Turner, so this syndrome is commonly known as Turner syndrome.
Characteristics of Turner Syndrome
Turner syndrome affects the primary and secondary sexual characteristics in females.
The person with these conditions are usually sterile in condition, they are also short in stature and webbing of skin occurs and also webbing of neck is a common symptom.
The person with this syndrome usually have other disorders such as hearing problems, cardiac abnormalities, vision loss, etc.
There is no absolute cure for this disorder but they can be given speech and other intellectual trainings to improve their motor areas of the brain.
There are usually short in stature and there will be inadequate progress in their sexual development.
It is usually diagnosed by antenatal tests at the time of pregnancy.
Types of Turner Syndrome
Turner syndrome is one of the most occurring genetic disorder which is caused due to an aneuploidy of sex chromosomes.
Where one X chromosome is found missing in all cells or few cells in our body. This condition occurs almost one in 2500 female births.
They are classified into types depending on how they affect the body cells.
I. Monosomy of X Chromosome
This is the most common type of syndrome occurring in most of the cases.
In this case there is a complete loss of one X chromosome. This occurs due to an abnormal cell division at the time of gamete formation.
In this condition egg or sperm cell losses one chromosome which results in only 45 chromosomes in all the cells, this result in XO where there will be no bar bodies.
Which means that X chromosome is not inactivated, but for the genes to get activated they must be present in pairs for the proper growth and development.
The sex chromosomes are lost during mitosis after fertilization. During the development of zygote, it results in 45 chromosomes in some cells and where as the other cells have normal 46 number of chromosomes. This also results in Turner syndrome.
Where as if the loss of chromosomes occurs late in the development, the number of aneuploidy cells are less and it results in reduced severity. When considering somatic mosaics, there will be a presence of 45X cells in few of the cells and in other cells it will be present in the extra X chromosome(47XXX).
In this condition girls are taller. In some cases, the female with Turner Syndrome has an extra Y chromosome along with that 46X chromosome which leads to the condition of developing a cancer known as gonadoblastoma.
III. X- Chromosome Abnormalities
During this condition the 20% of Turner Syndrome cases results in two X chromosomes which are present in all the cells, but only one chromosome has an abnormal structure.
This is usually due to the circular shaped chromosome which is present along the joint ends and forms a ring like structure which is known as ring chromosome.
Sometimes it may also result in a condition where one of the X chromosomes has one long arm instead of the q arm. Which results in two long arms in a single chromosome. It is known as Isochromosome.
Turner Syndrome Symptoms
The genetic make up of an individual varies accordingly depending upon the traits present in the chromosome.
Mostly females with this condition have rudimentary ovary and they are mostly sterile individuals along with short stature.
The most common symptoms of turner syndrome are Abnormal facial features like drooping eyelids, narrow palate along with short jaw line and abnormal earlobes which are set low than normal ones.
Growth is irregular among them in most of the cases.
Puberty is delayed, but the females with this condition have good intelligence and reading skills along with good verbal communication. But few of these people face learning difficulties as a results in difficulty in memorizing and also in solving the mathematical skills.
These people face difficulties in understanding the others emotion. These people suffer from undeveloped or poorly developed breasts and there will also be delay in menstrual cycles and in most of the cases they remain sterile.
There will also be other disturbances like murmuring of heart, due to the narrowing of aorta and other abnormalities in heart, liver and kidney which results in other symptoms.
Some symptoms also result in developing fetus, like Lymphedema which is characterized by swelling of muscles due to fluid leakage in the body.
It also causes swelling or thickness of neck which results in lower weight than normal.
Diagnosis of Turner Syndrome
These conditions can be diagnosed at the time of pregnancy by the process of amniocentesis or other tests like ultra soundwave therapies which helps us to find the karyotype of the fetus.
Turner syndrome can also be identified in infants by swelling of hands and feet and also other problems with kidney and heart and also webbed neck with broad chest and nipples are widely placed.
In some cases, it cannot be diagnosed till puberty.
Turner Syndrome Treatment Options
Though there is no permanent cure for turner syndrome, the other severe symptoms arising along with this such as vision and hearing problems can be treated.
We can also keep a regular check at heart discomforts and thyroid issues.
Hormone therapy is followed now a days to prevent short stature, which also helps in inducing the sexual development.
Invitro fertilization can be followed to get pregnancies among this kind of people.
Other intellectual activities can be improved by giving proper therapies.
Turner Syndrome Citations
- Fertility and Pregnancy in Turner Syndrome. J Obstet Gynaecol Can . 2016 Aug;38(8):712-8.
- Turner Syndrome: transition from childhood to adolescence. Metabolism . 2018 Sep;86:145-153.
- Turner Syndrome: Care of the Patient: Birth to Late Adolescence. Pediatr Endocrinol Rev . 2017 Jun;14(Suppl 2):454-461.
- Turner syndrome. Pediatr Rev . 2013 Sep;34(9):420-1.
- Turner syndrome: diagnosis and management. Am Fam Physician . 2007 Aug 1;76(3):405-10.
- Turner syndrome: mechanisms and management. Nat Rev Endocrinol . 2019 Oct;15(10):601-614.