Condition AZ: h

Fibular hemimelia (FH)
In FH, the fibular (calf-bone) fails to develop in part or in whole. Usually, only one leg is affected and it is usually the right. This can result in a range of problems, including:

• mild bowing of the leg
• the affected leg may be shorter
• soft tissues can be affected, including muscle and ligaments attached to the fibula that stabilise the knee joint
• knee instability, which can lead to a ‘knock-knee’ appearance
• the ankle may be unstable with a reverse ‘club-foot’ appearance.

Tibial hemimelia (TH)
In TH the tibia, one of the long bones in the leg, fails to develop in part or in whole and can occur in one or both legs. Symptoms include:

• deficiency of the ligaments that support the knee. The knee can have a ‘knock-knee’ appearance or be hypermobile (move around too much)
• sometimes it can be difficult to straighten the knee
• as the inner side of the ankle is usually missing the foot may be pointing downwards and inwards, often in a fixed position known as clubfoot
• there may be extra toes or the foot may have a cleft/split.

Radial hemimelia (RH)
In RH, also known as radial clubhand, the radius (one of the two large bones of the forearm) fails to develop normally either in part or in whole and this can affect one or both arms. Symptoms include:

• shortened forearm and the wrist in a fixed bent position with the hand lying to the thumb-side of the wrist
• the thumb may be small or absent, with one or two fingers on the hand missing
• soft tissues such as muscles and ligaments may be affected
• the ulna may overgrow or be bowed and the shoulder may be affected
• rarely, there are cardiac (heart), kidney, trachea (windpipe) and oesophagus (the tube that food goes down to the stomach) problems.

The condition may be linked with other disorders such as TAR syndrome or Fanconi anaemia.

Ulna hemimelia (UH)
In UH, also known as ulnar club hand, the ulna bone of the forearm fails to develop properly. In most people, just one arm is affected and symptoms include:

• the position of the hand tends to drift to the little-finger-side of the wrist and sometimes fingers may be short or absent.
• there may be synostosis (where the radius is fused to the ulna). Rarely, there are associated abnormalities of the femur (thigh bone), fibula or shoulder blade.

Most cases of hemimelia occur for no apparent reason. Some genetic mutations (changes in DNA) have been identified for some types of hemimelia such as those associated with TAR syndrome or Fanconi anaemia. Families that are worried about genetic problems causing hemimelia should seek advice from a geneticist. Some medications have been linked with hemimelia, for example insulin with FH. It is thought that sometimes an insult (damage to the baby) in the early weeks of development in the womb can cause hemimelia.

This is based on examination by a doctor and X-rays. In rare cases, tests may find a genetic problem causing the hemimelia.

Treatment will vary according to how severely the individual is affected and an orthopaedic specialist will advise on what treatment is necessary. Non-surgical treatments may be used instead of surgery, or before and after surgery, to help reduce the symptoms of hemimelia. Initially treatment involves bandaging or strapping and gentle manipulative exercises, usually under the supervision of a physiotherapist. Depending on how severely the limb is affected, surgery may be necessary to improve the quality of life of the person affected. Surgical removal of extra toes will help for shoe comfort or fitting of an orthotic limb (artificial leg). Leg lengthening if a limb is shortened may also be carried out. In upper limb abnormalities correcting the skewed wrist position may be beneficial.

Inheritance patterns
Not typically seen. Some syndromes demonstrate an inheritance pattern such as TAR syndrome (see entry).

Prenatal diagnosis
An anomaly ultrasound scan at 20 weeks may show up limb abnormalities.

There is no support group for Hemimelia 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.

Affected children usually suffer epileptic seizures (see entry Epilepsy) soon after birth (although these may be delayed until later in infancy) and display learning and psycho-motor difficulties. Later, children will display a hemiplegia, a weakness down one side. The condition may also be associated with facial enlargement and skin disorders. Other disorders may also involve malformation of one hemisphere, without the enlargement. Such children present with similar clinical features and require a similar course of management. The degree of developmental delay varies from mild to severe.

Treatments may prevent seizures and improve the quality of life. The first line of treatment for seizures would be medication, although early consideration with regard to surgery should be given. Many children benefit from surgery, namely hemispherectomy, which is disconnection or removal of the abnormal hemisphere. It is unlikely this hemisphere is doing anything except causing seizures, therefore function is unlikely to be compromised over and above what would be inevitable from the malformation (e.g. hemiplegia).

Inheritance patterns
None.

Prenatal diagnosis
Ultrasound scanning may show up the different sizes of the cerebral hemispheres. Prenatal screening and genetic advice may be offered for future pregnancies. Ante-natal MR scan at 20 to 25 weeks in specialist units may also give further information.

There is no support group for hemimegalencephaly in the UK. Cross referrals to other medical information entries on our website are intended to provide relevant support for those particular features of the disorder. Organisations identified in those entries do not provide support specifically for hemimegalencephaly.

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

British Heart Foundation

Helpline: 0300 330 3311
Email: via website
Website: bhf.org.uk

The Foundation is a Registered Charity in England and Wales No. 225971. It provides information and support to anyone affected by a heart condition, and produces publications specifically for children and young people. The Foundation funds research and promotes training in emergency life support skills. 

Group details last reviewed December 2022.

Sommerville Heart Foundation

Helpline: 0300 015 1998
Email: [email protected]
Website: thesf.org.uk

Sommerville Heart Foundation is a Registered Charity in England and Wales No. 1138088. It provides information and support to young people and adults born with a heart condition.

Group details last updated March 2025.

Heartline Families

Email: [email protected]~
Website: heartline.org.uk

The Organisation is a Registered Charity in England and Wales No. 1153442. It provides information and support for families of children with congenital and acquired heart conditions. The Organisation offers subsidised caravan holidays, free wetsuits for babies and children with heart conditions, and a handbook for parents. 

Group details last reviewed December 2020.

SADS UK (Sudden Arrhythmic Death Syndrome)

Tel: 01277 811 215
Email: [email protected]
Website: sadsuk.org

The Trust is a Registered Charity in England and Wales No. 1113681. It provides information and support to individuals and families affected by cardiac conditions or a sudden cardiac death. The Organisation offers short breaks for individuals and families, support contacts in different parts of the country and qualified counsellors. 

Group details last updated April 2025.

Children’s Heart Federation

Helpline: 0300 561 0065
Email: [email protected]
Website: chfed.org.uk

The Federation is a Registered Charity in England and Wales No. 1120557. It provides information and support to children with congenital or acquired heart disease and their families. The Federation provides information for parents and carers, produces a newsletter and is involved in research projects.

Group details last updated April 2025.

Arrhythmia Alliance

Helpline: 01789 867 501
Email: [email protected]
Website: arrhythmiaalliance.org.uk

The Alliance is a Registered Charity in England and Wales No. 1107496.  It is a coalition of charities, patient groups, patients, carers, medical groups and allied professionals who work together to improve the diagnosis, treatment and quality of life for all those affected by arrhythmias. 

Group details last reviewed December 2022.

Cardiac Risk in the Young (CRY)

Tel: 01737 363 222
Email: [email protected]
Website: c-r-y.org.uk
The Organisation is a Registered Charity in England and Wales No. 1050845. It provides information and support to young people diagnosed with cardiac conditions and offers bereavement support to families affected by young sudden cardiac death.

Group details last reviewed December 2022.

The following parent support groups are based around specific regional hospitals carrying out paediatric cardiac surgery or cover regional parts of the country:

ECHO (Evelina Children’s Heart Organisation)

Tel: 020 7998 4710
Email: [email protected]
Website: echo-uk.org

The Organisation is a Registered Charity in England and Wales No. 1146494. It provides support for children and young people with heart conditions who receive treatment at the Evelina London Children’s Hospital and the outreach clinics at local General Hospitals attended by Evelina Cardiologists. The Organisation supports their families and carers, and provides information, friendship and moral support from infancy to adulthood, especially at times of high anxiety.

Group details last updated December 2022.

Children’s Heartbeat Trust

Tel: 02890 312228
Email: [email protected]
Website: childrensheartbeattrust.org

The Trust is a Registered Charity in Northern Ireland No. XT 21039. It provides emotional and practical support to parents and families of children with heart disease in Northern Ireland.

Group details last reviewed December 2022.

Scottish Association for Children with Heart Disorders (SACHD)

Email: [email protected]
Website: youngheart.info

The Association is a Registered Charity in Scotland No. SC035499. It offers information and support to parents and families of children with heart disorders in Scotland. The Association has seven local area branches and offer holiday breaks and family weekends.

Group details last reviewed December 2022.

Young at Heart

Information line: 0121 357 8200
Email: [email protected]
Website: youngatheart.org.uk

The Group is a Registered Charity in England and Wales No. 512815. It provides information and support to families of babies and children diagnosed with heart defects that are being or have been treated at Birmingham Children’s Hospital. The Group offers regular ward visits to support parents, and brings families together through social events.

Group details last reviewed December 2022.

Children’s Heart Association

Tel: 01706 221 988
Email: [email protected]
Website: heartchild.info

The Association is a Registered Charity in England and Wales No. 267893. It provides information and support to families with, or who have had, children with heart disorders. The Association works closely with paediatric cardiac units across England, and has branches in the North West of England, centered around Alder Hey Children’s Hospital in Liverpool and the Royal Manchester Children’s Hospital.

Group details last reviewed December 2022.

Patients with Hashimoto’s encephalitis often present with a depression of brain function (meaning that function is reduced), drowsiness and sometimes coma. Two types of Hashimoto’s encephalitis have been described:

• the relapsing and remitting type (where symptoms at times worse and other times better) – which manifests with encephalopathy (a change in function or structure of the brain) and ‘stroke-like’ episodes
• the diffuse progressive (widely dispersed) type – which has a slow onset and a progressive course with occasional fluctuations and manifests with psychiatric symptoms, such as confusion, disorientation and psychosis.

Either of these may present with tremors, jerks or epileptic seizures.

Currently, the exact cause is unknown. High levels of thyroid antibodies are a marker of Hashimoto’s encephalitis rather than the cause of the condition. Thyroid function is usually normal.

It is a diagnosis of exclusion and the differential (alternative diagnoses that are similar to the condition) is wide, ranging from stroke-like episodes, Alzheimer’s diseases, Creutzfeldt-Jakob disease, to rare inborn errors of metabolism (see entry Inherited Metabolic disease). Useful tests to detect the presence of Hashimoto’s encephalitis include magnetic resonance imaging (MRI) of the brain, electroencephalogram (EEG), examination of the cerebrospinal fluid (CSF), endocrine and metabolic screens, and viral studies.

Most patients with Hashimoto’s encephalitis improve after treatment with high-dose steroid, such as prednisolone. However, improvement may take weeks or even months. Because of the improvement with steroids, some experts refer to the condition as ‘steroid-responsive encephalopathy associated with autoimmune thyroiditis (SREAT)’. Plasma exchange and intravenous immunoglobulin (IVIG) have been used in some patients. The prognosis with treatment is generally good. Steroids are often continued for many months.

Inheritance patterns
None.

Prenatal diagnosis 
None.

Information and support in the UK for Hashimoto’s Encephalitis is provided by the Encephalitis Society (see entry Encephalitis).

Haemophilia Society

Helpline: 020 7939 0780
Email: [email protected]
Website: haemophilia.org.uk

The Society is a Registered Charity in England and Wales No. 288260. It provides information and support to anyone affected by a bleeding disorder. The Society offers a range of services for children, including activity weekends. 

Group details last reviewed June 2025.

The effects of excess iron in the body depend more on the rate and age at which it occurs than on the cause. In young children and adults, there are effects on the heart and hormone system: there are palpitations and irregularities of the heartbeat, which can be dangerously rapid; the pumping function can also fail, causing breathlessness and swelling of the legs and abdomen. The hormonal effects cause diabetes (excess sugar in the blood) with thirst and excess urine; fatigue and failure to grow through puberty are common, too.

Acquired haemochromatosis

This usually occurs due to accumulated iron from frequent blood transfusions given to treat haemolytic anaemias; it can also arise from excess administration of oral iron and occasionally spontaneously in hereditary anaemias, especially when red blood cells are prematurely being broken up by the body. Frequent transfusions are necessary for children with anaemias, and therefore iron overload affects them easily.

Genetic haemochromatosis

This is an inherited condition. Excess absorption of iron from the diet persists despite normal or high body iron stores. Over 90 per cent of patients have two copies of the C282Y mutation in the HFE gene on chromosome 6 – a few patients have mutations in the transferrin-receptor gene type 2 and those with mild disease have changes in the ferroportin gene. In patients with rapid-onset and severe disease, different mutations occur in the hepcidin and haemojuvelin genes.

Initial detection of iron overload is by blood tests to identify transferrin saturation and ferritin.

For genetic haemochromatosis, mutation analysis for the C282Y HFE mutation identifies those patients affected. More sophisticated studies are required to find the other genetic forms.

Acquired haemochromatosis

This type of haemochromatosis is treated, and indeed prevented, by the use of iron chelation therapy, using a drug such as desferrioxamine given by injection or infusion, or oral agents such as Exjade and deferriprone. These bind iron in the body and allow it to be excreted in the urine and faeces.

Genetic haemochromatosis

Early diagnosis and treatment by venesection is important to reduce disease progression. Venesection therapy is the taking of approximately one pint of blood, usually every week, until iron levels return to normal. Subsequently venesection continues at a less frequent rate (three to six monthly) for life to prevent iron accumulation. Juvenile disease may require heart transplantation, hormone supplements including insulin for diabetes – and combined agents to prevent the rapid loading of iron.

Inheritance patterns
Genetic haemochromatosis is inherited in an autosomal recessive manner.

Prenatal diagnosis
Prenatal diagnosis for the genetic form is not currently used.

Haemochromatosis Society

Tel: 020 8449 1363
Email: [email protected]
Website: haemochromatosis.org.uk

The Society is a Registered Charity in England and Wales No. 1001307. It provides information and support to individuals and families affected by haemochromatosis. The Society promotes greater knowledge of the condition among medical professionals and the public, and supports research.

Group details last updated December 2014.