TURNER SYNDROME

Edited by, SOWNDHARYA

    Turner syndrome, a condition that affects only females, results when one of the X chromosomes (Sex chromosomes) is missing or partially missing. Turner syndrome can cause a variety of medical and developmental problems, including short height, failure of the ovaries to develop and herat defects.

    Turner syndrome may be diagnosed prenatally, during infancy or in early childhood. Occasionally, in females with mild signs and symptoms of turner syndrome, the diagnosis is delayed until the teen or young adult years.

     Girls and women with Turners syndrome need ongoing medical care from a variety of specialists. Regular check-ups and appropriate care can help most girls and women lead healthy, independent lives.

SYMPTOMS:

    The signs and symptoms of Turner syndrome may vary among girls and women with the disorder. For some girls, the presence of Turner syndrome may not be readily apparent, but in other girls, a number of physical features and poor growth are apparent early. Signs and symptoms can be subtle, developing slowly over time or significant, such as heart defects.

BEFORE BIRTH: Turner syndrome may be suspected prenatally based on prenatal cell-free DNA Screening- a method to screen for certain chromosomal abnormalities in a developing baby using a blood sample from a mother or prenatal Ultrasound. Prenatal ultrasound of a baby with Turner syndrome may show:

• Large fluid collection on the back of the neck or other abnormal fluid collections (oedema)

• Heart abnormalities

• Abnormal kidneys

AT BIRTH OR DURING INFANCY:

   The signs of Turner syndrome at birth or during infancy may include;

• Wide or weblike Neck

• Low-set ears

• Broad chest with widely spaced nipples

• High, narrow roof of the mouth(palate) 

• Arms that turn outward at the elbows

• Finger nails and toenails that are narrow and turned upward

• Swelling of the hands and feet, especially at birth

• Slightly smaller than avarage height at birth

• Slowed growth

• Cardiac defects

• Low hairline at the back of the head

• Receding or small lower Jaw

• Short fingers and toes

In childhood, teens and adulthood, the most common signs in almost all girls, teenagers and young women with Turner syndrome are short stature and ovarian insufficiency due to ovarian failure that may have occured by birth or gradually during childhood, the teen years, or young adulthood. 

Signs and symptoms of these include:

• Slowed growth

• No growth spurts at expected times in childhood

• Adult height significantly less than might be expected for a female member of the family

• Failure to begin sexual changes expected during puberty

• Sexual development that "stalls" during teenage years

• Early end to menstrual cycles not due to Pregnancy

• For most women with Turner syndrome, inability to conceive a child without fertility treatment

CAUSES:

   The genetic alterations of Turner syndrome may be one of the following:

• Monosomy: The complete absence of an X chromosome generally occurs because of an error in the father's sperm or in the mother's egg. This results in every cell in the body having only one X chromosome.

• Mosaicism: In some cases, an error occurs in cell division during early stages of foetal development. This results in some cells in the body having 2 complete copies of the X chromosome. Other cells have only one copy of the X chromosome.

• X chromosome abnormalities: Abnormal or missing part of one of the X chromosomes can occur. Cells have one complete and one altered copy. This error can occur in the sperm or egg with all cells having one complete and one altered copy. Or the error can occur in cell division in early foetal development so that only some cells contain the abnormal or missing parts of one of the X chromosomes (mosaicism).

• Y chromosome material: In a small percentage of Turner syndrome cases, some cells have one copy of the X chromosome and some Y chromosome material. These individuals develop biologically as female, but the presence of Y chromosome material increases the risk of developing a type of Cancer called gonadoblastoma.

COMPLICATIONS:

• Heart Problems: Many Infants with Turner syndrome are born with heart defects or even slight abnormalities in heart structure that increase their risk of serious complications.Heart defects often include problems with the aorta, the large blood vessel that branches off the heart and delivers oxygen-rich blood to the body.

• High blood pressure: Women with turner syndrome have an increased risk of developing diseases of the heart and blood vessels.

• Hearing loss: Hearing loss is common with Turner syndrome. In some cases, this is due to the gradual loss of nerve function. An increased risk of frequent middle ear infections can also result in hearing loss.

• Vision problems: Girls with Turner syndrome have an increased risk of weak muscle control of eye movements (strabismus), near sightedness and other vision problems.

• Kidney Problems: Girls with Turner syndrome may have some malformation of the kidneys. Although these abnormalities generally don't cause medical problems, they may increase the risk of high Blood Pressure (BP) and Urinary Tract Infection (UTI).

• Autoimmune disorders: Girls and women with Turner syndrome have an increased risk of an underactive thyroid (hypothyroidism) due to the autoimmune disorder Hashimoto's thyroiditis. They also have an increased risk of diabetes. Some may have gluten intolerance (celiac disease) or inflammatory bowel disease.

• Skeletal problems: Problems with the growth and development of bones increase the risk of abnormal curvature  of the spine (scoliosis) and forward rounding of the upper back (kyphosis). Women with Turner syndrome are also at increased risk of developing weak, brittle bones (Osteoporosis)

• Learning Disabilities: Girls and women with Turner syndrome usually have normal intelligence. However there is increased risk of learning disabilities, particularly with learning that involves spatial, concepts, math, memory and attention.

• Mental health issues: Women and girls with Turner syndrome may have difficulties functioning well in social situations and have an increased risk of attention-deficit/hyperactivity disorder (ADHD)

• Infertility: Most women with Turner syndrome are infertile. However a, very small number of women may become pregnant spontaneously, and some can become pregnant with fertility treatment.

•Pregnancy Complications: Because women with Turner's syndrome are with increased risk of complications during pregnancy, such as High Blood Pressure aortic dissection, they should be evaluated by the cardiologist before pregnancy.