Turner Syndrome

The Condition

Description

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 are infertile due to underdeveloped ovaries. In most cases, this condition is not diagnosed until puberty.

Anatomy

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). In the case of normal 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).

Causes

Turner syndrome is caused due to a chromosomal variation that occurs randomly at conception.

Impact

Girls with Turner’s syndrome 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 usually have a very short attention span and are hyperactive, restless and impulsive. This causes problems in a classroom setting.

Symptoms

Girls with Turner syndrome usually present with the following features:

  • At birth:
    • Lymphedema: Swollen hands and feet caused by accumulation of fluid in the tissues; usually resolves after birth
    • Thickness and swelling of the neck
    • 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.
  • Inadequate production of sex hormones by the ovaries. This is characterized by:
    • Incomplete or no development of secondary sexual characteristics (breasts and pubic hair)
    • May not menstruate monthly
    • Infertility
  • General features:
    • 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
  • Associated conditions:
    • Heart murmur. An abnormal sound during or between heartbeats
    • Kidney problems
    • Urinary tract infections
    • Hypothyroidism
    • Hypertension
    • Osteoporosis (brittleness of bones)
    • Scoliosis (abnormally curved spine)
    • Diabetes
    • Obesity
    • Lymphedema
    • Gastroenterological problems: Bleeding and ulcers in the stomach and intestines

Diagnosis

Turner syndrome can be identified at various stages of growth:

  • Prenatal:
    • Ultrasound scan is performed to check for kidney or heart problems.
    • Amniocentesis is done to check for any genetic abnormality.
  • Birth and childhood:
    • Identified by the presence of lymphedema, heart or kidney problems at birth and 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:
    • Incomplete development of secondary sexual characteristics
    • In severe cases, no development of secondary sexual characteristics.
    • Decreased height

Untreated

If not treated, girls will have a very short stature of usually less than 5 feet, incomplete sexual development, and infertility. Other complications could include hearing loss, abnormal skeletal development as well as heart, kidney, and liver dysfunction. The girls may also develop psychological problems such as low self-esteem and insecurity due to a negative body image.

Treatment

Treatment Options

There is no cure for Turner syndrome other than symptomatic management. This would include:

  • 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
  • Growth hormone therapy:  Helps increase the height of the child. It can be given in the form of injections starting around 5-6 years and continuing until 15-16 years.
  • Oestrogen replacement therapy:  These are sex hormones that are 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 at 11 years of age and continued until menopause. It can be given as a tablet, gel, or patch.
  • Progesterone replacement therapy: These are sex hormones that are administered for initiation of menses. 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: Assisted conception techniques such as in vitro fertilization and egg donation

Treatment-prognosis

Even though life expectancy is slightly less than normal and most individuals are slightly shorter in height than average in spite of growth hormone therapy, the overall prognosis is good. Since it does not cause mental retardation, most adult women with Turner syndrome can be gainfully employed.  In case of infertility, pregnancy is possible with assisted conception techniques.

Research

Extensive research has been done on treatment of Turner syndrome. Some studies include:

  • 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.
  • 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.