What is Mosaic Turner Syndrome?

Mosaic Turner syndrome is a condition caused by the presence of a chromosomal deficiency that adversely affects a female's sexual development. Caused by erroneous fetal cell division, this form of Turner syndrome generally manifests with either an X-chromosome deficiency or mutation. Often inducing additional developmental issues, this syndrome requires lifelong treatment that generally includes the administration of hormone therapy and supportive medical care, such as regular checkups. Proactive measures are essential to promoting some semblance of normalcy and delaying potential complication onset, including sensory issues and compromised organ function.

Under normal circumstances, a child inherits an X-chromosome from her mother and an X-chromosome from her father, resulting in a perfectly matched pair of X chromosomes. In the presence of mosaicism, the child’s chromosomal makeup is significantly altered, resulting in either a deficiency or alteration that is carried throughout her sex cells. This means she may have one X-chromosome, two complete X-chromosomes, or one normal X-chromosome paired with an altered one.

Frequently, this form of Turner syndrome may be diagnosed while the fetus is in utero. Developmental abnormalities may be detected during the administration of a routine ultrasound, prompting additional diagnostic tests such as amniocentesis or chorionic villus sampling. Signs and symptoms of mosaic Turner syndrome may also present during the first few weeks and months of life.

An infant with this type of Turner syndrome may exhibit a wide chest and neck, distended hands and feet, and sagging eyelids. Many with this condition are abnormally small at birth, especially in length, and may exhibit an underdeveloped lower jaw. Not all children born with this condition present with symptoms early on and may only show signs of Turner syndrome during their adolescent years.

Those with mosaic Turner syndrome often demonstrate delayed growth, presenting with short height and a pronounced absence of common prepubescent changes or meeting of adolescent developmental milestones. Due to a lack of estrogen, she may plateau in her sexual development and experience an abrupt end to her menstruation in the absence of pregnancy. Other signs that may occur include learning, communication, and interpersonal difficulties. Girls and young women with Turner syndrome often experience difficulty learning, especially certain analytical concepts such as math, and may present with a flat affect or pronounced apathy.

Treatment for mosaic Turner syndrome is primarily centered on hormone therapy, including the regular administration of somatropin, or human growth hormone, and estrogen. The administration of estrogen is essential to promoting proper physical development as would normally occur during puberty. Women with this condition must often seek help from a fertility expert to conceive and are considered to be a high-risk pregnancy, though it should be noted that success is generally dependent on the functionality and condition of the individual’s reproductive system.

Due to the extensive nature of potential complications, lifelong proactive medical care is essential to creating some sense of normalcy and slowing the progression of complication development. Considering mosaic Turner syndrome is a condition that may adversely impact an individual’s overall physical development, several of her body's systems may demonstrate issues later in life. It is not uncommon for individuals with Turner syndrome to be born with a congenital heart defect that may increase their risk for cardiovascular issues in adulthood, including hypertension and heart disease. Additionally, individuals may develop compromised immunity, psychological issues, and sensory difficulty, such as impaired vision and hearing that may aggressively deteriorate resulting in a loss of that sense.


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Post 3

I wondered my whole life why I have so many problems. It wasn't until I was in my late 50s that my D.O. told me off handed that I have Turner Syndrome. I have the thick neck (means my bra straps fall all the time), the smaller bone doesn't connect at the elbow, (can't put my palms up), dip in my sternum, enough my heart is out of place. It also means the electricity goes the long way to my lower chambers, with ear aches, no vagina or uterus, horseshoe kidneys, and only 5'2" where my parents were 5'10" and 6'3". I am often clueless socially, can't do math above multiplication. Some of my organs are undersized, e.g., gallbladder.

Post 2

@Lostnfound: Well, according to the Turner Syndrome Society, it's not as uncommon as you might think. They say over 70,000 women in the USA have it, and it occurs in one of every 2,500 live births. So that's not terribly rare.

They also say that every patient is different, so that may be why better treatments haven't been available for it.

Post 1

Is this syndrome detectable in an amniocentesis, and is it hereditary? It must not be very common, since I don't think I've ever known of anyone having it.

It sounds like one of those conditions researchers aren't giving much attention to, except for symptomatic care.

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