Almost all girls with Turner syndrome will grow up to be shorter than average, with underdeveloped ovaries.
Girls with Turner syndrome also have distinctive features and associated health conditions, some of which may be apparent from birth.
They may be born with swollen hands and feet, caused by a build-up of excess fluid (lymphoedema) in the surrounding tissues, but this usually clears soon after birth.
Other features that may have developed in the womb include:
- thick neck tissue
- swelling of the neck (cystic hygroma)
- being a small baby
- heart conditions
- kidney abnormalities
Babies with Turner syndrome may grow at a normal rate until they're 3 years old. After this, their growth slows down.
At puberty, usually between 8 and 14 years, a girl with Turner syndrome will not have the normal growth spurt, even with female oestrogen hormone replacement (HRT).
Girls with Turner syndrome are typically short in relation to the height of their parents. On average, adult women with untreated Turner syndrome are 20cm (8in) shorter than adult women without the syndrome. Treatment with additional high-dose growth hormone reduces this difference by about 5cm (about 2in) on average.
Read more about growth hormone treatment in Turner syndrome.
Ovaries are the pair of female reproductive organs that produce eggs and sex hormones. During puberty, a girl's ovaries usually begin to produce the sex hormones oestrogen and, once fully mature, progesterone. These trigger periods to begin.
Around 90% of girls with Turner syndrome don't produce enough of these sex hormones, which means:
- they may not begin sexual development or fully develop breasts without female hormone replacement therapy (HRT)
- they may begin sexual development but not complete it
- they may not start their monthly periods naturally
- it's likely they'll be unable to have a baby without assistance (infertile)
Even though many women with Turner syndrome have undeveloped ovaries and are infertile, their vagina and womb develop normally. This means they're able to have a normal sex life following treatment with female hormones.
Most girls need hormone replacement therapy (HRT) with oestrogen from around 10 to 12 years of age to begin breast development, and about 3 years later with added progesterone to bring on monthly periods.
A minority (10%) of girls with Turner syndrome experience some physical changes naturally during puberty, but only a very small number (1%) become pregnant naturally.
There are many other symptoms or characteristics that can affect girls and women with Turner syndrome.
- a particularly short, wide neck (webbed neck)
- a broad chest and widely spaced nipples
- arms that turn out slightly at the elbows
- a low hairline
- mouth abnormalities, which can cause teeth problems
- a large number of moles
- small, spoon-shaped nails
- a short fourth finger or toe
- eyes that slant downwards
- droopy eyelids (ptosis)
- a squint (strabismus)
- lazy eye (amblyopia)
- cataracts – cloudy patches in the lens at the front of the eye
- short-sightedness (myopia)
- low-set ears
- recurring middle ear infections (otitis media) and glue ear during early childhood
- hearing loss – this can occur in later life, but is often more severe and develops earlier than the normal age-related decline in hearing
Turner syndrome is often associated with a number of other health conditions, including:
- heart murmur – where the heart makes a whooshing or swishing noise between beats; this is sometimes linked to a narrowing of the main blood vessel in the heart (the aorta) and high blood pressure
- kidney and urinary tract problems – this can increase the risk of developing urinary tract infections (UTIs) and high blood pressure
- underactive thyroid gland (hypothyroidism) – this happens in around 10 to 30% of women with Turner syndrome; regular blood tests are needed to detect it early before it causes symptoms
- high blood pressure (hypertension)
- brittle bones (osteoporosis) – in adult life, this may develop if oestrogen isn't adequately replaced by HRT
- abnormal curvature of the spine (scoliosis) – this should be screened for
- diabetes – a lifelong condition that causes a person's blood sugar level to become too high
- obesity – this increases the risk of type 2 diabetes and stroke, and can be reversed by following a healthy diet and taking regular exercise
- lymphoedema – this can occur at any age, not just in newborn babies
- bleeding in the digestive system – caused by abnormalities in the blood vessels in the intestines
- other digestive conditions – such as Crohn's disease and ulcerative colitis are more common in females with Turner syndrome but still rare
Most girls with Turner syndrome have good language and reading skills. However, some have behavioural, social and specific learning difficulties.
About a third of girls with Turner syndrome have problems understanding social relationships because of the way their brain develops.
This can make it difficult to sustain friendships and leads to relationship problems in later life, both at home and at work.
Spatial awareness and numeracy
Spatial awareness is the ability to understand where you are in relation to objects or other people.
More than 8 out of 10 females with Turner syndrome have difficulty understanding spatial relationships. This may cause problems when learning to drive or following directions on a map.
A similar number have some degree of difficulty learning or understanding maths. This is known as dyscalculia.
Attention and hyperactivity problems
Typically, girls with Turner syndrome will go through a phase in childhood that involves:
- physical overactivity, such as constant fidgeting and restlessness
- acting impulsively, such as breaking rules or having no sense of danger
- having a short attention span and being easily distracted
Attention and hyperactivity problems usually begin when the girl is a toddler but may not be a serious problem until the girl starts school at 4 or 5. Girls with Turner syndrome may have difficulty settling in class.
Medicines used to treat attention deficit hyperactivity disorder (ADHD) may not be as effective in cases of Turner syndrome.
The physical hyperactivity usually reduces around the time the girl starts secondary school at 11 years of age, although problems with inattention can last longer, into the teens.