Condition AZ: t

Multiple Births Foundation

Tel: 020 3313 3519
Email: mbf@imperial.nhs.uk
Website: multiplebirths.org.uk

The Foundation is a Registered Charity in England and Wales No. 1094546. It provides information and support for multiple birth families and professionals. 

Group details last updated March 2016.

TAMBA (Twins & Multiple Births Association)

Helpline: 0800 138 0509
Email: asktwinline@tamba.org.uk
Website: tamba.org.uk/home

TAMBA is a Registered Charity in England and Wales No. 1076478. It provides information and support to multiple birth families. TAMBA has a closed Facebook page for parents with multiples who have a child or children with special needs, and a special needs message board for members.

Group details last updated September 2014.

There is no support group for Turcot syndrome in the UK. Cross referrals to other entries in Contact’s directory are intended to provide relevant support for those particular features of the disorder. Organisations identified in those entries do not provide support specifically for Turcot syndrome.

Families can use Contact’s freephone helpline for advice, information and, where possible, links to other families. To meet other families with disabled children, join Contact’s closed (private) Facebook group.

Tuberous Sclerosis Association UK

Tel: 0808 801 0700
Email: support@tuberous-sclerosis.org
Website: tuberous-sclerosis.org

The Association is a Registered Charity in England and Wales No. 1039549. It provides information and support to anyone affected by Tuberous Sclerosis Complex.

Group details last reviewed September 2023.

The most frequent symptom of TB disease is a wet or ‘productive’ cough (where mucous or phlegm may be coughed up, although often children may swallow it). The phlegm may be bloodstained. There is often a persisting fever, sweating at night, chest pain and loss of appetite and weight. TB can also cause meningitis, kidney and bone/joint disease. To be infectious to other people you have to be coughing the organism out into the air.

Many people have no symptoms and have a hidden, non-infectious form called ‘Latent TB’. This can reactivate and cause significant illness at some time in the future. It is estimated that one third of people in the world may have latent TB.

A type of bacteria called Mycobacterium tuberculosis causes TB.

The organism may be seen (under a microscope) or cultured (grown in a laboratory) from phlegm of an infected individual. If a patient is unable to spit out phlegm it is sometime possible to help using a nebuliser. In children, the overnight stomach contents can be aspirated through a tube passed through the nose into the stomach (naso-gastric tube), allowing samples to be collected for analysis to see if Mycobacterium tuberculosis is present.

A biopsy (removal of a small piece of tissue for further analysis) of an infected gland may also identify the typical changes that are observed in TB infection.

A skin test (mantoux) and/or a blood test (IGRA) may identify people exposed to the infection.

When a person is diagnosed with infectious TB, other people close to them will then be screened to see if they have been exposed.

TB is curable if it is correctly diagnosed and the right antibiotics are used. Usually four medicines (antibiotics) are prescribed for two months followed by two medicines continuing for a further four months. It is very important to complete the course of treatment. Some TB is resistant to one or more drugs and treatment may need to be longer and more complicated.

Latent TB is treated with two antibiotics for three months (or one antibiotic for six months). The aim is to prevent the infection progressing to symptomatic disease and the risk of infecting other people.

Inheritance patterns 
Not applicable.

Prenatal diagnosis 
Not applicable.

Information and support in the UK for tuberculosis is provided by the British Lung Foundation (see entry Lung diseases).

Symtpoms of TN include:

• spasms of sharp, stabbing pain, often described as like a jolt of lightning.
• the pain is confined in the area served by the branches of the TN nerve: lower jaw, upper jaw, cheek, eye and forehead. The pain may include one, two or all three branches of the TN nerve
• pain is almost always on one side of the face, most commonly the right-hand side
• the pain is usually provoked by a light touch on the face, movements of the face (and therefore mouth), washing the face, a light breeze. Trigger points are usually around the nose and lip
• the pain might disappear by itself for weeks, even months, and return.

The cause of TN is still an area for debate among medical professionals. Most believe that the deterioration of the myelin (protective coating of the nerve) allows the transmission of abnormal messages of pain. The damage of the myelin sheath may be caused by pressure from blood vessels or arteries, tumours, multiple sclerosis, injury to the nerve, consequences of shingles, or just the ageing process.

Diagnosis of idiopathic TN is made entirely on history but tests for tumours pressing on the nerve or multiple sclerosis may be required to be eliminate symptomatic TN. Magnetic resonance imaging (MRI) of the brain is done to determine if a blood vessel is pressing on the nerve.

If, after several visits to a dentist, a GP or an oral surgeon, TN is suspected, the patient is sent to a neurologist. He will perform some neurological tests to rule out or discover other diseases. He will also ask for a precise description of the pain. Most doctors will recommend a MRI scan in order to see if there is any obvious cause.

A number of drugs, mainly anti-epileptic, are used to treat TN singly or in combination. As these drugs have a number of side effects, such as drowsiness or a feeling of inability to concentrate, the specific drugs for an individual are dictated by efficacy and affect. If a drug regime fails to alleviate pain or leads to unacceptable side effects, surgery may be considered. There are a wide variety of surgical procedures available, all with their own risks but they give much longer pain relief periods. Due to the rarity of the condition and its severity, sufferers can feel isolated and fearful. Contact with a TN support group may be very helpful.

Inheritance patterns 
None.

Prenatal diagnosis 
None.

Trigeminal Neuralgia Association UK

Tel: 01883 370 214
Email: help@tna.org.uk
Website: tna.org.uk

The Association is a Registered Charity in England and Wales No. 1155001. It provides information and support to people affected by Trigeminal Neuralgia, and raises awareness of the condition within the medical community and the general public.

Group details last updated December 2014.

The most common problems are short stature, sparse hair, and restricted joint movements. There are often other problems with the bones and joints, which may appear as congenital hip problems, Perthes disease of the hip, and early onset osteoarthritis of other joints. Almost any joint can be affected. People with TRPS type 2 can also develop multiple exostoses, which are benign bony tumours (or lumps) that grow on the bones. Although not painful themselves, these can press on surrounding muscles or ligaments, causing limitations of movement, discomfort or pain. Some people with TRPS also suffer from learning difficulties and this is more common in TRPS type 2. People with TRPS often comment that they look similar to other people with TRPS that they have met. Orthodontic problems, deafness and susceptibility to infections can also occur.

TRPS is a genetic condition, meaning it is caused by an alteration to a person’s genetic makeup. This person may be the first in the family with the disease, or may have inherited it from a parent. Sometimes the syndrome can be traced back through several generations. In some people, the genetic alteration may be a change in the genetic code of a gene called TRPS1 which is found on chromosome 8. In others, the whole gene may be missing. In people with TRPS type 2 (Langer-Giedion syndrome), a small piece of chromosome 8 is usually missing, which means that not only is the TRPS1 gene missing, but also another genes, and this can cause additional problems. Commonly, a gene called EXT1 is missing, which causes benign bony tumours or growths called exostoses to develop.

The diagnosis is usually made on the findings at clinical examination, and the shape of the bones (cone-shaped epiphyses) when seen on a hand X-ray. The diagnosis can in some cases be confirmed by checking the patient’s chromosomes for a deletion on chromosome 8q, or by molecular genetic analysis of the TRPS1 gene.

There is currently no treatment that will cure the whole syndrome. Individual problems are managed as needed. In childhood, growth and development should be monitored. Simple analgesia can relieve joint pains. A reduction in mobility should be investigated as Perthes disease of the hip can frequently occur. Multiple exostoses can develop in TRPS2, typically from early to mid childhood. Adults frequently require joint replacement surgery in the fifth and sixth decades of life due to degenerative changes in the large joints. Sparse hair and premature hair loss can result in reduced self-esteem. Hair extensions may help some, but the exceptionally brittle hair seen in some patients may not support them.

Inheritance patterns
Autosomal dominant with many cases occurring as a sporadic new mutation.

Prenatal diagnosis
Chorionic villus sampling (CVS) or amniocentesis may be available for a family if the diagnosis has been confirmed on chromosome or DNA analysis. Referral to a regional genetics centre for genetic counselling is indicated.

TRPS Support Group UK

Email: info@trpsuk.org
Website: trpsuk.org

The Group was established in 2009. It provides information and support to those affected by trichorhinophalangeal syndrome and their families. The Group offers a closed online forum as an opportunity to share experiences, knowledge and a sympathetic understanding of all aspects of the disorder. 

Group details last updated December 2019.

With OA, the oesophagus does not connect the mouth and stomach properly, but forms a closed off pouch that prevents food from reaching the stomach. If it is not corrected, this pouch can fill up with food and saliva, which can eventually overflow into the baby’s trachea (windpipe), entering the lungs and causing choking. With TOF, usually the lower part of the oesophagus is connected to the windpipe. Without treatment, this causes air to pass from the windpipe to the food pipe and stomach. It can also allow stomach acid to pass into the lungs.

Most commonly, babies have both TOF and OA, though on rare occasions either TOF or OA can occur on their own.

VACTERL Association
Babies with TOF/OA may also have other health problems, particularly heart defects, imperforate anus (opening to the anus is missing or blocked) and problems with the kidneys, spine and limbs. There is a recognised association between a particular group of difficulties, which has been called the VACTERL Association.

Unfortunately, the causes of TOA/OA are still unknown.

Doctors will suspect TOF/OA if babies froth at the mouth, splutter or choke after their first attempt at feeding, or have laboured breathing and/or blueness of the lips and fingertips. If OA is suspected, a tube will be passed down into the oesophagus from the mouth. When the baby has an OA, the tube will not pass beyond the end of the upper part of the oesophagus, and this finding will confirm the diagnosis. If the tube goes right down to the stomach then this rules out the diagnosis.

Babies with TOF/OA require intensive care in a special baby unit. Surgery to correct the TOF/OA usually happens within days of the baby being born. Some children have to undergo additional surgery later on in life.

Inheritance patterns
None in the majority of cases.

Prenatal diagnosis
Maternal polyhydramnios (excessive quantity of amniotic fluid) may indicate the presence of oesophageal atresia especially if accompanied by a small or absent stomach in the developing fetus. This can be detected by prenatal ultrasound. All babies born to a mum who has polyhydramnios should have a tube passed into the oesophagus at birth to rule out OA.

TOFS (Tracheo-Oesophageal Fistula Support)

Tel: 0115 961 3092
Email: info@tofs.org.uk
Website: tofs.org.uk

The Organisation is a Registered Charity in England and Wales No. 327735. It provides information and support to families of children born with Tracheo-Oesophageal Fistula (TOF), Oesophageal Atresia (OA) and associated conditions. The Organisation offers one-to-one support from parents and relatives with experience of caring for a child with TOF/OA, social events and activities, and an online community.

Group details last updated December 2014.

In healthy adults and children, infection may be without symptoms. In some cases, infection may present as a mild flu-like illness. The infection can cause serious health problems for anyone with suppressed or damaged immunity, for example people on immune suppressing drugs or people with AIDS (see entry HIV infection and AIDS).

Toxoplasmosis is one of a small group of infections that can transmit to the fetus (unborn baby) if caught for the first time during pregnancy. The risk of transmission and the degree of damage done depend on when in pregnancy the woman catches the infection. In the first trimester, the damage may be very severe, however it is less likely that infection is transmitted at this stage of pregnancy. Later on in pregnancy, the damage is less severe, but the infection is more likely to transmit and cause congenital infection (infection at birth).

Severe damage includes excess fluid on the brain (see entry Hydrocephalus), calcifications of the brain tissue that can lead to developmental delay (see entry Global Developmental Delay) and epilepsy, and damage to the retina (a light-sensitive film at the back of the eye) of one or both eyes known as retinochoroiditis. More severe damage to the brain is rare.

Damage in a severely affected infant will be apparent soon after birth. However, the vast majority of babies with congenital infection will appear normal at birth. Unless these babies are treated, problems especially with the eyes, will develop in childhood, the teens or even later.

If a woman feels she has been at risk through something she ate, or if she has symptoms that could indicate toxoplasma infection, she can request a blood test. All positive tests should be sent to the toxoplasma reference laboratory for confirmation and an estimate of infection onset.

Where an infection is diagnosed during pregnancy, specific antibiotic treatment can help limit the risk of the infection crossing to the fetus. If the fetus is found to be infected, stronger anti-parasitic drugs may be given to help limit the damage, and this treatment would also be given to all infants born with congenital infection. Treatment for congenital infection may be given for up to up to one year.

Inheritance patterns
Not applicable.

Prenatal diagnosis
This requires a specific blood test on the pregnant woman. This is not done routinely in the UK. If a woman is confirmed as having toxoplasmosis infection during pregnancy and the onset of infection is considered to be recent, the fetus can be tested using amniocentesis. Ultrasound scans can show up severe damage as a result of toxoplasmosis infection, but not the minor forms. If a scan raises suspicion about damage to the unborn baby, only a blood test could confirm toxoplasmosis as the cause.

Information and support in the UK for toxoplasmosis is provided by Tommy’s – the baby charity (see entry Prematurity and Sick Newborn).

There is no support group for toxocariasis in the UK. Families can use Contact’s freephone helpline for advice and information. Meet other parents online in our closed Facebook group

Anal anomalies associated with TBS may include absence of a normal opening (imperforate anus) with a passage connecting the rectum to the vagina (rectovaginal fistula), abnormal placement of the anus and narrowing of the anal passage (anal stenosis). Typically, the ears of individuals with TBS may be large, or small, abnormally developed (dysplastic) ears, lop ear (over-folded ear helix) or have preauricular tags or pits (a rudimentary tag of ear tissue typically located just in front of the ear). Individuals may experience hearing loss (see entry Deafness) due to structural anomalies in the inner ear (sensorineural deafness) or because of anomalies in the external or middle ear (conductive deafness). The thumbs may be underdeveloped (hypoplastic) or have the appearance more of a finger than a thumb. Webbed fingers (syndactyly) may occur, as well as fusion of the bones in the wrist.

A number of other features may also be associated TBS. These involve other systems in the body. The bones in the feet of some children may be fused with overlapping toes leading to mobility difficulties (see entry Lower Limb Abnormalities). TBS may affect the kidney, and underdeveloped (hypoplastic) kidneys, multicystic kidneys, abnormal (dysplastic) kidneys and kidney failure have been reported (see entry Kidney disease). Abnormalities associated with the heart may include tetralogy of fallot and ventricular septal defects (see entry Heart Defects). Whilst severe heart and kidney problems may be life-threatening, many individuals with TBS have a normal life span.

Learning difficulties have been reported in some children with TBS. For others, intelligence is within the normal range.

Inheritance patterns
TBS is inherited as an autosomal dominant trait. Changes in a gene located on chromosome 16 are associated with the characteristic features.

Prenatal diagnosis 
It may sometimes be possible to perform prenatal diagnosis by chorionic villus sampling (CVS) or amniocentesis during pregnancy. Genetic counselling may be helpful for individuals and families affected by this condition.

There is no support group for Townes-Brocks syndrome. Cross referrals to other entries in Contact’s directory are intended to provide relevant support for those particular features of the disorder. Organisations identified in those entries do not provide support specifically for Townes-Brocks syndrome.

Families can use Contact’s freephone helpline for advice, information and, where possible, links to other families. To meet other families with disabled children, join Contact’s closed (private) Facebook group.

Tourettes Action

Email: Via website
Website: tourettes-action.org.uk

The Organisation is a Registered Charity in England and Wales No. 1003317. It provides information and support to anyone affected by Tourette Syndrome in England, Wales and Northern Ireland, and has a network of support groups.

Group details last reviewed September 2023.

Tourette Scotland

Email: help@tourettescotland.org
Website: tourettescotland.org

The Organisation is a Registered Charity in Scotland No. SC021851. It provides information, advice and support for children and adults with Tourette Syndrome (TS) and everyone involved in their lives. The Organisation has a network of local groups across Scotland, groups for children and private Facebook groups.

Group details last reviewed September 2023.

Tinnitus can be a very distressing condition. However, with the correct support it can be well managed. Tinnitus can be most disturbing in quiet situations, and as with adults, children may have difficulty getting to sleep at night.

Noisy environments can also cause problems. Loud sounds such as school bells may trigger the onset of troublesome tinnitus, and so the school environment can be particularly challenging for children with tinnitus. In the classroom, tinnitus can make concentration difficult, competing against the teacher’s voice for the child’s attention. Those with hearing loss (see entry Deafness) may find it more difficult to understand speech when tinnitus is present, meaning that information is missed.

Tinnitus has been found to be more common in children with hearing loss, both sensorineural and conductive (see entry Deafness). Those with a moderate/severe sensorineural hearing loss have a higher rate of tinnitus than those with a profound loss, and those with an acquired hearing loss are more likely to experience tinnitus than those with a congenital (present at birth) hearing impairment.

Any child or young person with tinnitus should be referred for a thorough otological (structure of the ear) and audiological (hearing) assessment in order to rule out any underlying problems.

In some cases the tinnitus is associated with a reduction in sound tolerance (hyperacusis) and this may also be diagnosed.

In the first instance, any associated hearing loss should be appropriately investigated and appropriately treated.  Tinnitus is often a consequence of hearing loss.  So treating the associated hearing loss will often reduce the intrusiveness of any associated tinnitus.

Tinnitus counselling makes a difference to children and young people, but only when information is presented at a level the child can understand. Whilst children are going to sleep, the use of sound therapy may be helpful, using simple background sounds such as an inexpensive environmental sound generator, fans, or quiet background music to distract from tinnitus.

Good liaison with school can make a big difference. Teachers also need information about tinnitus, what it is, and how it affects their particular pupil. Working under pressure and in a very quiet environment can make tinnitus particularly difficult to ignore.

It is important to alert the class teacher and the school to the child’s tinnitus and request that special arrangements are made for exams. For example, exams can be sat in a separate room with a fan or some other environmental sound that the child finds helpful as a tinnitus masker.

Inheritance patterns 
Current  research does not indicate that the condition is inherited. However, there are some suggestions of a genetic predisposition (meaning that some people with a certain genetic make-up may be more likely to have the condition).

Prenatal diagnosis 
None.

British Tinnitus Association

Helpline: 0800 018 0527
Email: helpline@tinnitus.org.uk
Website: tinnitus.org.uk

The Association is a Registered Charity in England and Wales No. 1011145, established in 1992. It offers information and advice about tinnitus and coping techniques together with support and contact with others through local groups. It publishes a quarterly magazine called Quiet and has medical information leaflets available.

Group details last updated September 2020.

RNID (formerly Action on Hearing Loss)

Tinnitus Helpline: 0808 808 6666
Email: tinnitushelpline@rnid.org.uk
Website: rnid.org.uk

The Organisation is a Registered Charity in England and Wales No. 207720, and Scotland No. SC038926. It provides information and support for people with hearing loss and tinnitus. The Organisation offers day-to-day care for people who are deaf and have additional needs; communication services and training; and practical advice to help people protect their hearing. It campaigns to change public policy and supports research into an eventual cure for hearing loss and tinnitus.

Group details updated June 2021.

Swelling of the damaged tissues behind the eyes can cause the eyes to become red and swelling to occur above and below the eyes. It may also cause the eyes to be pushed forward (‘starey eyes’, ‘proptosis’). In more severe cases, the damage at the back of the eye causes swelling and stiffness of the muscles that move the eye, causing double vision. This occurs especially when looking from side to side as the muscles cannot keep the eyes exactly in line with each other. Occasionally, the swelling behind the eyes is severe enough to press on the nerve from the eyes to the brain affecting vision.

Other features that may occur include mild soreness and grittiness of the eyes usually only affecting one eye, increased watering of the eye, a dislike of bright lights and a feeling of discomfort behind the eyes especially when looking up or side to side. Puffiness of the upper eyelid or around the eyes giving the impression of baggy eyes is also common and is worse first thing in the morning. The eyes often appear ‘starey’ and drying of the eyes or too many tears can cause blurry vision which comes and goes.

Ninety per cent of people with thyroid eye disease also have an overactive thyroid gland (thyrotoxicosis). Graves’ disease is a type of thyrotoxicosis which is autoimmune in aetiology. A feature of both Graves’ disease and thyroid eye disease is thought to be the common molecule, the thyrotrophin stimulating hormone (TSH) receptor to which stimulating antibodies develop. Thyroid eye disease and an overactive thyroid gland do not always develop at the same time and the treatment for one does not affect the treatment of the other, with the exception of radioactive iodine treatment. A small number of people with thyroid eye disease may have an underactive thyroid with some having no thyroid disturbance at all.

Treatment for thyroid eye disease depends on the severity and ranges from simple eye drops to immunosuppressive therapy and decompressive surgery. The most important aspect of treatment is the preservation of eyesight.

Inheritance patterns
None.

Prenatal diagnosis 
None.

Thyroid Eye Disease Charitable Trust

Tel: 0844 800 8133
Email: ted@tedct.co.uk
Website: tedct.co.uk

The Trust is a Registered Charity in England and Wales No. 1095967. It provides information and support to all those affected by thyroid eye disease. 

Group details last updated September 2014.

Children with thalassaemia major are healthy at birth but become pale within the first few months of life. They fail to grow and develop normally, are prone to infections, develop enlargement of the bones (particularly facial and skull bones) have an enlarged spleen and liver. Without treatment, they develop severe complications of anaemia (where the amount of haemoglobin in the blood is below the normal level) such as heart failure and do not survive.

The condition is caused by mutations which affect the production of the beta chain of haemoglobin. This results in low levels of haemoglobin.

Thalassaemia major is treatable, and in some cases curable. Treatment consists of regular (usually 3 to 4 weekly) transfusion of red blood cells. This corrects the anaemia and prevents bone deformity. It enables normal growth and development.

Additional treatment is required to control the build-up of iron. Iron build-up (overload) occurs because transfused red blood cells contain iron, and the body does not have an effective natural means of disposing of iron. If untreated, iron overload will cause damage – specifically to the heart, liver and hormone-producing glands. Iron overload is managed with iron removal (chelation) therapy.

There are several drugs available to chelate iron, and for most patients, a long-term chelation regime can be found to control iron effectively. The currently licensed iron chelation drugs are desferrioxamine (given by subcutaneous – under the skin – infusion usually 5 nights per week), deferiprone (orally administered three times per day) and deferasirox (orally administered once per day). Occasionally, a specialist will advise a combination of these drugs.

Many patients can consistently adhere to the prescribed medications, and maintain acceptable haemoglobin and iron levels. They do not develop severe complications, have a good quality of life and a good life expectancy. Those whose adherence is erratic or experience adverse reactions to the chelation medications, may experience complications caused by iron overload, such as growth disturbance, failure of pubertal development, thyroid and parathyroid dysfunction, diabetes, heart and liver problems.

Thalassaemia major can be cured during childhood by a procedure called bone marrow transplantation. This is only possible when there is a bone marrow donor (usually a brother or a sister) who has the same tissue-type (is histocompatible with the patient). Unfortunately, for many patients, a donor is not available.

Inheritance patterns
Autosomal recessive. People who have only one copy of the altered gene (carrier of thalassaemia, thalassaemia trait) are healthy. They need a simple blood test to detect if they are a carrier so they can have appropriate advice about planning a family.

Prenatal diagnosis
If the mutation in a family is known, molecular testing (testing DNA) of cells obtained from the placenta during early pregnancy either via amniocentesis or chorionic villus sampling will identify if the condition is present in the unborn baby.

UK Thalassaemia Society

Tel: 020 8882 0011
Email: office@ukts.org
Website: ukts.org

The Society is a Registered Charity in England and Wales No. 275107. It provides information and support to children and adults affected by Thalassaemia and their families, and offers counselling services. 

Group details last updated December 2014.

Storage of GM(2)ganglioside begins during pregnancy. However, the baby usually develops normally until about six months of age. The nervous system becomes progressively affected and sadly the disease is usually fatal between age three to five years. The child becomes blind, deaf and unable to swallow. Muscles begin to waste and paralysis develops. Additionally, epileptic seizures may occur.

Late-onset Tay Sachs disease (LOTS) is much less common than the classical infant form. Individuals with LOTS have very reduced enzyme levels rather than complete absence.

Onset of LOTS is later and individuals vary in the way it affects them.

Tay Sachs is caused by mutations in the HEXA gene, which provides instructions for making part of an enzyme called beta-hexosaminidase A. This enzyme is located in lysosomes, which are structures in cells that break down complex molecules and act as recycling centres. Tay Sachs disease is part of a group of conditions called lysosomal storage disorders (LSDs).

Tay Sachs patients and carriers (those that carry only one mutation in the gene and are not affected by the condition) can be identified by a blood test that measures beta-hexosaminidase A activity.

There is no cure for Tay Sachs disease. Treatment involves making the child feel as comfortable as possible by treating the associated symptoms. Anticonvulsant medication may be used to control fits. Children may require supportive measures with feeding when swallowing becomes difficult.

For a number of LSDs a replacement enzyme can be manufactured to replace the missing enzyme. The enzyme replacement therapy (ERT) is usually given regularly into a vein. Enzymes are big molecules that cannot cross into the brain and so there is very limited improvement of neurological problems. Recently, trials have started for a number of neurological LSDs by infusing enzyme into the brain via the cerebrospinal fluid (CSF), though ERT is not yet available for Tay Sachs disease.

Another way to replace enzymes is to transplant stem cells – usually as an umbilical cord transplant. Transplanted cells become part of the bone marrow and are capable of making enzyme. This is highly experimental for Tay-Sachs disease, particularly the infantile form, as the disease progresses too rapidly to prevent severe neurological disease. This should never be attempted outside very experienced centres that are properly regulated.

Inheritance patterns
The mode of inheritance is autosomal recessive. One in 25 Ashkenazi Jews and 1 in 250 of the general population are carriers of this disease. Carrier detection is available through genetic clinics.

Prenatal diagnosis
It is recommended people from at risk population undergo testing before starting a family. Prenatal testing from chorionic villus sampling (CVS) during pregnancy can detect Tay Sachs disease.

Cure & Action for Tay-Sachs (CATS) Foundation

Email: info@cats-foundation.org
Website: cats-foundation.org

The Foundation is a Registered Charity in England and Wales No. 1144543. It was established in 2011, and provides a variety of information and support for families living with Tay-Sachs, including (but not limited to) provision of short breaks and purchase of specialist equipment. The Foundation is also actively involved in raising awareness and funding for research, and publishes a regular newsletter.

Group details last updated October 2015.

TAR syndrome is characterised by absence of the radius in both arms and a reduction in the number of platelets. As platelets help blood to clot, a reduction means there may be a higher level of bleeding and bruising. People with TAR syndrome may also be slightly shorter than normal and underdevelopment of other bones in the arms and legs may occur. TAR syndrome may be associated with distinctive facial features including a micrognathia (small lower jaw), a prominent forehead and low-set ears. About 50 per cent of people with the condition experience difficulty digesting cow’s milk (the symptoms of which are diarrhoea, failure to thrive and lowering of platelets), whilst around 30 per cent have a congenital heart defect (see entry Heart Defects). There can also be problems with the kidneys.

Almost everyone diagnosed with TAR syndrome has a deletion from the long (q) arm of chromosome 1 at position 1q21.1. On the other chromosome 1 there is also usually a small change (known as a single nucleotide polymorphism, SNP) in the DNA sequence in the regulatory region of the gene RBMSA.

Diagnosis can be made on the observation of the clinical features of TAR syndrome. X-rays to look at the bones of the skeleton and examination of blood and bone marrow to look for low levels of megakaryocytes (the cells that make platelets) will confirm the diagnosis. Specific testing is available to establish carriers (those that carry the genetic mutation causing the condition, but are not affected).

There is no cure for TAR syndrome. Treatment focuses on relieving the symptoms. Platelet transfusion (receiving platelets directly into one’s circulation) for thrombocytopenia may be required to boost platelet levels and reduce bleeding. If repeated platelet transfusions are needed, a single donor should be identified so as not to develop antibodies.

An orthopaedic specialist will need to advise on interventions to help with limb problems. Cow’s milk should be avoided to reduce the severity of gastroenteritis and to avoid making thrombocytopenia worse. Surgery to mend heart defects may be also be required.

Inheritance patterns
The deletion of genetic material on chromosome 1 associated with this condition can be passed through generations in families. SNPs in the regulatory region of RBMSA can also be passed through many generations. Some deletions occur sporadically (by chance) in people with no history of the disorder in their family. Once TAR has occurred, the recurrence risk for future children of those parents may be as high as 25 per cent. The risk to a person with TAR of having affected children is very small but their partner could be tested for molecular changes that would predispose them to having an affected child. In addition, the siblings of the affected individual could be tested to see if they are carriers.

Prenatal diagnosis
An ultrasound scan at 12 weeks may show up the absent radii and other limb deformities. Chorionic villus sampling can be offered to detect the genetic change causing TAR syndrome if the mutation in the family is identified.

There is not currently a support group for TAR syndrome in the UK.

Families can use Contact’s freephone helpline for advice, information and, where possible, links to other families. To meet other families with disabled children, join Contact’s closed (private) Facebook group.