What Causes Turner Syndrome?

What is Turner Syndrome?

Every human baby is born with 23 pairs of chromosome or 22 pairs of autosomes and 1 pair of sex chromosomes that we receive from our parents. The sex chromosomes are XX in case of females (one from each parent) and XY in case of males. Babies born with Turner Syndrome have 1 partial or completely missing X chromosome leaving only 1 good X chromosome, this impacts a multitude of functions in the body.

Turner Syndrome Causes:

Turner Syndrome is a result of genetic aberration that happens during conception where the female baby misses a partial or a complete X chromosome from one of the parent. There is nothing the parents can do to avoid or prevent this as it is a random error with no known cause. In extremely rare cases it could be inherited from one of the parents.

Turner Syndrome Types:

There are two major types of Turner Syndrome and two rare forms based on how the X chromosome is affected.

• Monosomy X: As the names suggests, there is only 1 copy of X chromosome in all the cells of the body instead of two X chromosomes. Most cases of Turner Syndrome fall in this category.

• Mosaic Turner Syndrome: Some cells in the baby's body have two X chromosomes while the others have only 1 copy of the X chromosome.

• Inherited Turner Syndrome: In very rare cases a baby inherits the syndrome from one of the parents who passes on a partial X chromosome with missing part (partial deletion) while the other is a normal X chromosome.

• Y Chromosome Material: Extremely rare, where some cells in the baby's body have 1 X chromosome and the others have 1 X chromosome and a partial Y chromosome. Even though the babies grow up as females, the partial or some Y chromosome presence puts them at risk of gonadoblastoma, a type of cancer.

Turner Syndrome Symptoms

Turner Syndrome affects each baby differently with symptoms ranging from mild to severe and based on the type and severity the symptoms appear anytime ranging from prenatal, at birth, childhood, adolescence or at adulthood. Turner Syndrome could cause a multitude of symptoms, some babies show a few to none while others may show all.

• Most if not all cases of Turner Syndrome cause short stature

• Slow growth with developmental delays

• May not experience puberty, breast development or menstrual periods without hormonal therapy at right age.

• Small ovaries that may not work properly or work well only for a few years causing infertility

• Low levels of sex hormones.

• Ear Abnormalities - Low set ears, thick earlobes, frequent infections, cup shaped or elongated ears and prone to hearing loss.

• Bone Issues - Frequent fractures, weak brittle bones, increased risk of osteoporosis, curved spine (Scoliosis)

• Cardiovascular Complications - Many are born with congenital heart defects, heart and valve issues and high blood pressure.

• Autoimmune Conditions - Prone to conditions like Celiac disease, Inflammatory Bowl Disease (IBD), and others.

• Vision Issues - More prone to Refractive errors, Dropping eyelids, Strabismus, and Lazy eye.

• Narrow and upward growing nails of fingers and toes. Missing knuckle in a toe or finger.

• Broad chest and wide, short neck with skin folds or webbed

• Colored skin pigmentation across the body

• Outward pointing arms at the elbows

• Small or deformed kidneys, increased risk of urinary tract infections (UTIs)

• Swelling in the hands and feet

• Narrow lower jaw impacting the gums, teeth development and causing crowded teeth.

Turner Syndrome Diagnosis

Turner syndrome is sometimes diagnosed before birth during blood test or ultrasound (specific features of baby) but in most cases it could be after birth or anytime during the child's lifetime. Tests used to diagnose Turner Syndrome:

• Non - Invasive Prenatal Testing (NIPT): Blood test done during 10 weeks of pregnancy to identify any chromosomal abnormalities that could point to conditions/syndromes like Down, Turner, Patau and many others.

• Ultrasound: Some cases are detected during pregnancy ultrasound scan, doctor could notice fluid or folds around the neck, cardiovascular defects and other features of Turner Syndrome.

• Amniocentesis or CVS (Chorionic Villus Sampling): Tests usually done to confirm the finding of ultrasound, along needle is inserted through abdomen of the pregnant woman to draw out some amniotic fluid or tissue from placenta to do a genetic test to confirm Turner Syndrome

• Physical Exam: Done at birth, where a doctor thoroughly checks the baby for any physical symptoms or defects to ensure the baby is well. In case of Turner Syndrome, the baby may show specific features that point to Turner Syndrome.

• Genetic Testing: Blood tests (New born Screening and others) done after birth to screen for specific genetic conditions like Turner Syndrome.

Turner Syndrome Treatment:

There is no cure for Turner Syndrome, however it can be managed with medications and hormonal therapy

• Growth Hormone Therapy: Child is treated early on with injections of Human Growth Hormone to help with vertical growth, timely treatment can help by adding several inches to your child's height.

• Estrogen Therapy: Estrogen injections are given at the age of puberty to help with breast development, menstruation, brain, bone development and overall body functioning as well

• Progesterone Therapy: Started at the age of puberty to induce regular menstrual cycle.

• Surgeries to treat any defects: cardiac surgery, as many babies with Turner Syndrome are born with cardiac defects.

Turner Syndrome Outlook

Turner Syndrome affects each baby differently, it is difficult to predict how it affects the child in long term. Based on the type and severity of the condition some children may have very mild to no symptoms and could lead normal lives while others may need medication, hormonal therapies and even surgeries to function. In most cases with timely interventions the child should go on to lead a close to normal life.