INFERTILITY MANAGEMENT: TURNER’S SYNDROME AND FERTILITY (PART 1)
Dr. Kemi AILOJE
Turner’s syndrome is a genetic condition affecting females and is characterised by the partial or total absence of one X chromosome. This usually occurs in assigned females at birth (AFAB). The condition can have several medical effects and may also affect development in various ways, including short stature, incomplete ovarian development, cardiac defects, and an increased risk of obesity.
Ovarian insufficiency is the most important infertility-related consequence of Turner’s syndrome. Reduced fertility is common because most affected women have underdeveloped ovaries and experience no menstrual periods (amenorrhoea) after puberty. While natural conception is rare, Assisted Reproductive Technologies and hormone treatments provide hope for parenthood.
The signs and symptoms of Turner’s syndrome range from prenatal diagnosis to early childhood presentation. Some patients may not show symptoms until late adolescence or even adulthood. Individuals with Turner’s syndrome should receive continuous medical care from a variety of specialists to enable them to live healthy and independent lives.
Some facts about Turner’s syndrome include:
Genetic Basis
Most times, the female infant is one of two sisters with normal XX chromosomes. In Turner’s syndrome, one of the X chromosomes is missing or structurally incomplete, resulting in a 45,X karyotype instead of the normal 46,XX.
Physical Features
Physical features commonly associated with the disorder include webbed neck (where skin folds occur on the sides of the neck), which may impair neck movement in severe cases, short stature, low-set ears, broad chest with widely spaced nipples, and a low hairline at the back of the head.
Turner’s syndrome can also cause heart defects, kidney problems, and hearing loss. Ovarian insufficiency or failure is common in girls with Turner’s syndrome, meaning many have difficulty becoming pregnant and may experience irregular menstrual cycles.
Developmental and Cognitive Features
Although intelligence is usually within the normal range, people with Turner’s syndrome may have specific learning disabilities or difficulties with spatial reasoning.
Symptoms of Turner’s Syndrome
Turner’s syndrome presents with a range of signs and symptoms that can vary widely among affected girls and women. In some cases, the disorder may not be immediately obvious, while in others, several physical features become evident early. Symptoms may be subtle and develop gradually over time, or they may be more pronounced, such as cardiac defects.
Before Birth
Turner’s syndrome may be suspected during pregnancy through prenatal testing, such as cell-free DNA screening, which detects certain chromosomal abnormalities using a blood sample from the mother, or through prenatal ultrasound. Indicators on ultrasound may include:
Heart abnormalities
Kidney dysfunction
Large fluid collection at the back of the neck
Other abnormal fluid accumulations (oedema)
At Birth or During Infancy
Signs of Turner’s syndrome at birth or during infancy may include:
Webbed neck
Cardiac defects
High or narrow palate
Receding lower jaw
Short fingers and toes
Low-set ears
Slowed growth
Low hairline at the back of the head
Arms that turn outward at the elbows
Broad chest with widely spaced nipples
Slightly smaller than average height at birth
Narrow upward-curving fingernails and toenails
Swelling of the hands and feet, especially at birth
In Childhood, Teen Years, and Adulthood
Common signs in young girls, teenagers, and young women with Turner’s syndrome include short stature and ovarian insufficiency due to ovarian failure. Ovarian failure may occur at birth or develop gradually during childhood, adolescence, or young adulthood. Associated symptoms may include:
Infertility
Slowed growth
Lack of sexual development
Absence of expected growth spurts during childhood
Early cessation of menstrual cycles not related to pregnancy
Adult height significantly shorter than expected for family members
Causes of Turner’s Syndrome
Most individuals are born with two sex chromosomes. Males inherit an X chromosome from their mother and a Y chromosome from their father, while females inherit one X chromosome from each parent. In Turner’s syndrome, one X chromosome is missing, partially missing, or altered.
The genetic abnormalities associated with Turner’s syndrome can be categorised as follows:
Monosomy
This condition occurs when one X chromosome is completely missing, usually due to an error in the sperm or egg. Consequently, every cell in the body has only a single X chromosome.
Mosaicism
This occurs when an error happens during cell division early in foetal development. As a result, some cells have two X chromosomes while others have only one.
X Chromosome Changes
This involves structural changes or partial deletion of one of the X chromosomes. Cells may have one complete X chromosome and one altered X chromosome. These changes may occur in the sperm or egg, resulting in all cells having one complete and one altered X chromosome. Alternatively, the error may occur during early foetal development, leading to mosaicism where only some cells have the altered X chromosome.
Y Chromosome Material
In a small percentage of Turner’s syndrome cases, some cells contain one X chromosome along with Y chromosome material. Individuals with this type of Turner’s syndrome develop biologically as females, but the presence of Y chromosome material increases the risk of developing a type of cancer known as gonadoblastoma.
Risk Factors
The alteration of the X chromosome occurs randomly. Sometimes it is due to a problem with the sperm or egg, while in other cases, the loss of the X chromosome occurs early in foetal development.
Family history does not appear to be a risk factor, making it unlikely that parents of one child with Turner’s syndrome will have another child with the disorder.
Effect of Turner’s Syndrome on Fertility
Turner’s syndrome significantly affects fertility due to the following factors:
Ovarian Insufficiency
The most notable effect is ovarian insufficiency or premature ovarian failure. In most individuals with Turner’s syndrome, the ovaries do not develop normally and fail to produce eggs or hormones. This usually results in the absence of menstrual periods and a reduced ability to conceive naturally.
Reduced Egg Reserve
The ovaries often contain a very limited number of eggs, leading to early depletion of the egg supply. This further impairs fertility and makes natural conception difficult.
Hormonal Imbalance
Due to underdeveloped ovaries, individuals with Turner’s syndrome often experience hormonal imbalances involving oestrogen and progesterone, which are essential for regulating the menstrual cycle and supporting pregnancy.
Infertility
As a result of these issues, most women with Turner’s syndrome are infertile. However, some may have a small number of functional follicles and could potentially conceive with medical assistance. For women with Turner’s syndrome who wish to have children, options such as in vitro fertilisation (IVF) using donor eggs are available. Hormone replacement therapy can also help with secondary sexual development and overall health.
…………………………………………………………… TO BE CONTINUED
Dr. Kemi AILOJE
Reproductive Endocrinologist, Infertility / IVF Specialist
Lifelink Fertility Center
Dr. Kemi AILOJE MD, MRMed, FWAPCP, Ph.D.
WhatsApp only: +2348033083580
