Turner syndrome produces a wide range of symptoms, but the two most consistent are short stature and ovaries that don’t function properly. Nearly every person with Turner syndrome experiences both. Beyond these hallmarks, the condition affects the heart, kidneys, hearing, bones, and cognitive development to varying degrees, depending on the specific genetic pattern involved.
Turner syndrome occurs when one of the two X chromosomes is missing or partially missing. It affects roughly 1 in 2,500 girls at birth, and symptoms can appear as early as a prenatal ultrasound or as late as the teenage years when puberty doesn’t arrive on schedule.
Short Stature and Growth Patterns
Growth failure is the most visible feature of Turner syndrome and often the first reason a family seeks evaluation. Without treatment, average adult height falls between 136 and 147 cm (roughly 4’6″ to 4’10”), depending on the population. Growth tends to slow noticeably in early childhood and falls further behind during the years when a typical growth spurt would occur at puberty. Growth hormone therapy can add several centimeters to final adult height, but the degree of improvement varies from person to person.
Puberty and Reproductive Health
The ovaries in Turner syndrome are typically smaller than average and may only function for a few years or not at all, a condition called primary ovarian insufficiency. For most girls, this means puberty is either delayed or absent entirely: breasts don’t develop, menstrual periods never start, and estrogen levels stay low. Low estrogen doesn’t just affect fertility. It has downstream effects on bone density, cardiovascular health, and overall well-being throughout adulthood.
The severity varies with the genetic pattern. Girls with a mosaic form, where only some cells are missing an X chromosome, are more likely to enter puberty on their own and even conceive naturally. Those with the classic 45,X pattern, where every cell is missing one X chromosome, face higher rates of complete ovarian failure.
Physical Features Visible at Birth
Some signs of Turner syndrome are present from the moment a baby is born. These include a short neck with extra skin folds (sometimes called a webbed neck), a low hairline at the back of the head, and low-set ears. Hands and feet may appear swollen or puffy in newborns, and fingernails and toenails can be soft and curve upward. Not every baby shows all of these features, and some are subtle enough that the diagnosis isn’t made until later in childhood.
During pregnancy, a large fluid-filled sac at the back of the fetal neck (cystic hygroma) on ultrasound is one of the strongest prenatal indicators. This finding is associated with Turner syndrome, though it can also appear in other chromosomal conditions.
Heart and Blood Vessel Problems
Cardiovascular abnormalities affect an estimated 23% to 45% of people with Turner syndrome, making heart screening a critical part of ongoing care. The most common defect is a bicuspid aortic valve, where the main valve leaving the heart has two flaps instead of the usual three. This occurs in roughly 13% to 34% of cases. Coarctation of the aorta, a narrowing of the body’s main artery, is the second most frequent problem.
Many of these heart differences cause no symptoms in childhood and are only discovered through imaging. But they carry long-term risks. People with Turner syndrome who have a bicuspid valve or aortic coarctation face a higher chance of aortic enlargement and, in rare cases, aortic dissection later in life. High blood pressure is also common and compounds these risks. Current guidelines recommend initial cardiac imaging in infancy, with follow-up around age 9 to 11 if early scans are normal, and ongoing monitoring into adulthood.
Kidney Differences
Kidney malformations occur frequently in Turner syndrome. The most recognized is horseshoe kidney, where the two kidneys are fused together at their lower ends. Many kidney differences cause no symptoms and are found incidentally during imaging for other reasons. However, some structural variations can increase the risk of urinary tract infections or affect how the kidneys drain, so imaging is typically part of the initial evaluation after diagnosis.
Hearing Loss and Ear Infections
Ear and hearing problems are among the most underappreciated symptoms of Turner syndrome. Up to 88% of affected individuals experience recurrent middle ear infections and problems with the tube that connects the middle ear to the throat. These infections can lead to conductive hearing loss, which affects as many as 80% of patients at some point.
As girls with Turner syndrome move into adolescence and adulthood, a different type of hearing loss emerges. Sensorineural hearing loss, which involves the inner ear or auditory nerve rather than the middle ear, becomes increasingly common. This type tends to be progressive, meaning it worsens over time, and regular hearing evaluations are an important part of lifelong care.
Bone Health and Fracture Risk
People with Turner syndrome break bones significantly more often than the general population, with fracture risk estimated at 1.4 to 2.2 times higher than average. This elevated risk begins in childhood and accelerates with age. One study found the odds of fracture were about twice as high in those under 45, but jumped to more than 19 times higher after age 45.
Several factors drive this. Low estrogen weakens bones over time. Related conditions like thyroid disorders, obesity, and diabetes, all of which occur at higher rates in Turner syndrome, further compromise bone strength. Maintaining adequate estrogen levels through hormone therapy and staying physically active are the primary strategies for protecting bone health.
Thyroid and Autoimmune Conditions
Turner syndrome increases the risk of autoimmune conditions, with thyroid disease being the most common. The thyroid may become underactive over time, leading to fatigue, weight gain, dry skin, and sluggish metabolism. This autoimmune thyroid inflammation develops gradually and may not cause noticeable symptoms until blood tests reveal it. Regular thyroid screening is standard practice for anyone with Turner syndrome, typically starting in childhood and continuing throughout life.
Cognitive and Social Differences
Overall intelligence is typically normal in Turner syndrome, and verbal skills are often a clear strength. The challenges tend to cluster in specific areas: spatial reasoning, executive function, and social cognition.
Spatial reasoning difficulties show up in tasks like reading maps, judging left from right, understanding how shapes fit together, or navigating unfamiliar environments. Executive function challenges can affect planning, organizing tasks, and switching between activities. These patterns sometimes lead to difficulties with math, which relies heavily on spatial processing, even when reading and language skills are strong.
Social cognition can also be affected. Some individuals have difficulty reading facial expressions, interpreting tone of voice, or navigating complex social situations. Researchers have debated whether these social challenges stem from the same nonverbal processing weaknesses or represent a separate issue. Either way, awareness of these patterns helps parents and teachers provide the right support early on.
How Genetic Pattern Affects Severity
Not everyone with Turner syndrome has the same genetic picture, and the specific chromosomal pattern shapes which symptoms appear and how severe they are. The classic form (45,X), where one X chromosome is completely absent in every cell, tends to produce the most pronounced features: more heart defects, higher rates of obesity and high blood pressure, and greater overall mortality risk.
Mosaic Turner syndrome (45,X/46,XX), where some cells have two X chromosomes and others have one, generally produces a milder set of symptoms. These individuals have fewer heart defects, are more likely to go through puberty naturally, and have a higher chance of spontaneous pregnancy. Another mosaic variant (45,X/46,XY) carries the lowest risk of autoimmune thyroid disease and reduced risk of aortic coarctation. The isochromosome Xq variant falls somewhere in between, with less cardiac involvement but otherwise intermediate features.
Because the range of symptoms is so broad, two people with Turner syndrome can look and feel very different from each other. This variability is one reason the condition sometimes goes undiagnosed until adolescence or even adulthood, particularly in milder mosaic cases where short stature may be the only obvious clue.