Turner syndrome, likewise known as gonadal dysgenesis (45 XO), is a genetic disorder where a baby girl is born with only one copy of the X chromosome instead of two. Chromosomes are the small threadlike structure of nucleic acids and proteins found in the nucleus of most living cells that carries genetic information in the form of genes. This genetic information is stored in 23 pairs of chromosomes, making it 46 altogether.
The 23rd pair is made up of two XX chromosomes in females and one X and one Y chromosome in a male. This means men have 46 chromosomes with the last pair being X and Y (chromosomes 46, XY), and women have 46 chromosomes, with the last two pairs being XX (chromosomes 46, XX).
Chromosomes always come in pairs in a normal healthy individual. One pair from the mother and the other pair from the father making up 46 chromosomes altogether.
Chromosomes determine how the human body and every organ develops as it grows in the uterus and how it continues to evolve after birth. Anything that causes the chromosomes to be less than 46 or create a replica of extra copy changes how the baby grows and leads to several health problems.
In Turner syndrome, the child only has 45 chromosomes altogether. The 23rd pair is either missing an X chromosome partially or wholly. Turner syndrome is not an inherited disorder, and it usually occurs as a result of a genetic defect as a random event during the formation of reproductive cells (eggs and sperm). There are no known predisposing factors. A mother’s age or environmental risk does not play a role whatsoever.
Signs and Symptoms of Turner syndrome:
- Short, wide webbed neck (is a skin fold that is present in the side of the neck down to the shoulders).
- Slow growth
- Short stature
- Abnormalities in the development of reproductive organs
- Dysplastic nails (poor growth of nails, narrowed fingernails, and toenails, small fingernails, nails that turned upward)
- The ear is positioned lower on the head than usual (low set ears).
- Swollen (puffy) hands and feet at birth
- Low hairline at the back of the neck
- Abnormally raised roof of the mouth (palate)
- Failure of teeth to develop normally
- Delayed puberty
- Amenorrhea (Absence of menses in some women with Turner’s syndrome)
- Hypertension (high blood pressure)
- Drooping eyelids
- Widely spaced nipples
- Increased number of moles
- Cubitus vagus (arms that turn outwardly away from the body at the elbows)
- Small mandibles (lower jaw)
- Shield chest (broad chest)
- Problems with concentration and memory deficits (mostly seen in younger years)
- Nonverbal learning disabilities.
Complications of Turner syndrome
- Heart defects
- Hypothyroidism (low thyroid hormone)
- Coarctation of aorta
- Female infertility
- Recurrent ear infections
- Hearing loss
- Kidney malformations (horseshoe kidneys)
Diagnosis of Turner syndrome
- Prenatal ultrasound: will show the presence of edema on the back of the neck, heart defect and kidney abnormalities
- Prenatal testing (amniocentesis or chorionic villus sampling)
- Postnatal period: Turner’s syndrome is diagnosed with the presence of typical physical features, complications, and genetic testing.
Treatment of Turner syndrome
There is no cure for Turner’s syndrome. Management is aimed at correcting any symptoms present that can be corrected. Techniques used are:
- Human growth hormone injections during childhood to increase height in adulthood.
- Estrogen replacement therapy to boost breast and hips development
- Fertility treatments.
- Turner’s syndrome occurs in 1 in every 2000 to 5000 live female birth worldwide.
- There are four variations of Turner’s syndrome: monosomy, mosaicism, X-chromosomes abnormalities and presence of Y chromosome material.