What is Turner Syndrome?
Turner syndrome is a genetic condition that affects approximately 1 in 2000 baby girls. Girls with Turner syndrome are usually short in stature, do not menstruate, and have problems with fertility due to underdeveloped ovaries. Commonly this condition is not diagnosed until puberty.
What Causes Turner Syndrome?
Turner syndrome is caused by a chromosomal variation that occurs randomly at conception
Each human cell contains 2 sex chromosomes. These determine the sex of the individual. In the case of males, the 2 sex chromosomes are dissimilar in appearance (XY). Usually in the case of females, the 2 sex chromosomes are similar in appearance (XX). A girl with Turner syndrome does not have one of the X sex chromosomes (classic Turner syndrome) or will have a missing part in one of her X sex chromosomes (mosaic Turner syndrome).
What is the Impact of Turner Syndrome?
Girls with Turner’s syndrome may be affected to different degrees, and may have difficulty with:
- Social interaction - The process of acting and reacting to others:
- This can lead to problems forming and maintaining relationships both at home and at school.
- Spatial awareness - Being aware of one’s body in relation to other people or objects in space:
- This may create problems driving or using a map.
- Numeracy - Difficulty understanding simple numerical concepts.
- Focusing ability
- Individuals with Turner syndrome may have a very short attention span and be hyperactive, restless and impulsive.
- This can cause problems in a classroom setting.
What are the Symptoms of Turner Syndrome?
Girls with Turner syndrome usually present with the following features:
- At birth:
- Swollen hands and feet caused by accumulation of fluid in the tissues (lymphoedema); this usually resolves after birth
- Thickness and swelling of the neck
- Low birth weight and overall small size
- Kidney problems
- Heart problems
- Growth rate abnormalities:
- Childhood: Growth is normal until 3 years of age when growth rate slows down.
- Puberty: There is no growth spurt during puberty.
- Adulthood: Height of an adult is shorter than average.
- Webbed (short and wide) neck
- Broad chest with increased distance between nipples
- Low hairline
- Crowding of teeth
- Increased number of moles
- Small nails that are spoon shaped
- Small fourth toe or finger
- Eye abnormalities:
- Downward slant
- Ptosis (drooping of eyelids)
- Strabismus (squint)
- Amblyopia (lazy eye)
- Cataracts (clouding of the lens)
- Myopia (short sightedness)
- Ear abnormalities:
- Recurrent ear infections
- Hearing loss
- Misshapen, low-set ears
- Inadequate production of sex hormones (oestrogen and progesterone) by the ovaries. This leads to:
- Incomplete or no development of secondary sexual characteristics (breasts and pubic hair)
- May not menstruate monthly - periods may not start at all, or may be very irregular before stopping altogether
- Impaired fertility
Other conditions may occur due to Turner Syndrome include:
- Heart murmur. An abnormal sound during or between heartbeats
- Kidney problems
- Urinary tract infections
- Osteoporosis (brittleness of bones)
- Scoliosis (abnormally curved spine)
- Lymphedema (swelling due to fluid retention in soft tissues)
- Gastroenterological problems: Bleeding and ulcers in the stomach and intestines
Turner syndrome can be identified at various stages of growth:
- NIPT (Non-Invasive Prenatal Testing) - This is a blood test done early in pregnancy to check for genetic changes. Many laboratories offer testing for Turner Syndrome on this test.
- Ultrasound scan performed to check for kidney or heart problems may indicate some features of Turner Syndrome
- Amniocentesis is done to check for any genetic abnormality can confirm a diagnosis of Turner Syndrome
- Birth and childhood:
- Turner Syndrome may be identified by the presence of lymphedema (swelling of the hands and feet), heart or kidney problems at birth, and / or a very slow growth rate after 3 years of age; other typical signs include thick neck, abnormally shaped ears, broad chest and widely spaced nipples.
- Blood tests are ordered to evaluate genetic makeup and confirm the diagnosis.
- Adolescence: In addition to those mentioned above other diagnostic features would include:
- Delayed and / or incomplete puberty, affecting development of secondary sexual characteristics (breasts and pubic hair)
- In severe cases, no pubertal changes (no development of breasts or pubic hair, no menstruation).
- Decreased height due to a lack of growth spurt with puberty
If not treated, girls will have a very short stature of usually less than 5 feet (152cm), incomplete sexual development, and infertility. Other complications could include hearing loss, abnormal skeletal development as well as heart, kidney, and liver problems. The girls may also develop psychological problems such as low self-esteem and insecurity due to a negative body image.
There is no cure for Turner Syndrome, but there are treatments for many of its features. Good medical care for girls and women with Turner syndrome includes:
- Regular health checks to identify and treat any complications that may arise, particularly in the following areas:
- Ear examinations and hearing tests:
- Due to increased susceptibility to ear infections leading to hearing loss
- Blood pressure monitoring:
- Due to increased likelihood of high blood pressure associated with underlying heart or kidney problems
- Thyroid function tests:
- Due to higher risk of hypothyroidism
- Glucose level monitoring in blood and urine:
- Due to higher risk of diabetes
- Bone mineral density test:
- Due to increased risk of osteoporosis
- Ear examinations and hearing tests:
- Growth hormone therapy:
- Supplemental Growth Hormone therapy helps to increase the height of the child. It can be given in the form of small injections under the skin (usually 6 days out of 7), starting in early childhood and continuing until 15-16 years.
- Oestrogen replacement therapy:
- Oestrogen is a sex hormone usually produced by the ovaries that is administered for development of breasts and sexual maturation. Oestrogen is also important for maintaining bone mineral density and preventing osteoporosis. This therapy is usually started around 11 years of age and continued through adulthood until menopause. It can be given as a tablet, gel, or patch.
- Progesterone replacement therapy:
- Progesterone is a sex hormone that are administered for initiation of menses (periods). It is usually started after oestrogen therapy and can be given along with oestrogen or separately. It is given in the form of a tablet or patch.
- Infertility treatment:
- Many women with Turner syndrome may wish to consider assisted conception techniques such as in vitro fertilization (IVF) and egg donation
Even though most individuals are slightly shorter in height than average in spite of growth hormone therapy and life expectancy is slightly less than normal, the overall prognosis for girls and women with Turner Syndrome is good. Turner Syndrome does not cause intellectual impairment, and most adult women with Turner syndrome can be gainfully employed. In case of infertility, pregnancy can be possible with assisted conception techniques.
Extensive research has been done on treatment of Turner syndrome. Some studies include:
- Y Dulac; C Pienkowski; S Abadir, M Tauber, P Acar. Cardiovascular abnormalities in Turner's syndrome: what prevention? Arch Cardiovasc Dis. 2008 Jul-Aug;101(7-8):485-90. doi: 10.1016/j.acvd.2008.05.007. Epub 2008 Aug 20.
- W H Price; J F Clayton; S Collyer; R De Mey and J Wilson. Mortality ratios, life expectancy, and causes of death in patients with Turner's syndrome. J Epidemiol Community Health. 1986 Jun; 40(2): 97–102.