Neuroacanthocytosis disorders
Also known as: Chorea-acanthocytosis; McLeod syndrome
Background
The term neuroacanthocytosis refers to a group of rare inherited conditions that result in abnormalities of the nervous system. Key features include abnormal movements (chorea, dystonia) and acanthocytosis (abnormal red blood cells with spur-like projections).
The main neuroacanthocytosis disorders are:
- chorea-acanthocytosis
- McLeod syndrome
Two other disorders with similar features can also be included in this group, which has caused confusion about the diagnosis in the past:
- Huntington’s disease-like 2
- pantothenate kinase-associated neurodegeneration (PKAN)
Two additional conditions have acanthocytes and neurological features, but no involuntary movements, and are now not included under this term:
- abetalipoproteinaemia (Bassen-Kornzweig syndrome)
- hypobetalipoproteinaemia.
Credits
Last updated November 2014 by Dr R Walker, Associate Professor of Neurology, Mount Sinai School of Medicine, New York, USA.
Chorea-acanthocytosis
Also known as: Levine-Critchley syndrome; Neuroacanthocytosis
This rare inherited condition usually develops in young adulthood, but occasionally starts in teenage years with tics and obsessive behaviours, accompanied by acanthocytosis – spur-like projections on red blood cells. The condition affects both sexes and occurs in all ethnic backgrounds. About five hundred cases have been reported.
- behaviour changes
- involuntary movements:
– chorea – irregular dancing movements
– dystonia – more sustained movements with posturing of the limbs, trunk, neck, face
– tics.
- Parkinsonism – slowed movements and stiffness of limbs
- impaired swallowing with weight loss
- lip and tongue biting
- difficulty with speech
- seizures in about half
- peripheral neuropathy
- enlargement of liver and spleen.
Mutations in the VPS13A gene on chromosome 9q21.
Chorea-acanthocytosis is diagnosed when the typical features are seen, especially facial movements with lip and tongue biting. Not all have acanthocytes, but most will have increased creatine phosphokinase. The diagnosis is made by looking for the affected protein, chorein. One lab in Munich performs clinical tests of VPS13A, but some other labs do this on a research basis.
Chorea-acanthocytosis cannot be cured. Treatment is directed at specific symptoms.
Inheritance patterns
Autosomal recessive.
Prenatal diagnosis
This may be possible in families already known to be affected. Affected families should be referred to their genetics service for further information and support.
Advocacy for Neuroacanthocytosis Patients
Tel: 020 7460 8874
Email: [email protected]
Website: naadvocacy.org
The Group is a Registered Charity in England and Wales No. 1133182. It provides information and support to neuroacanthocytosis patients and develops research aimed at alleviation of the disease. The Group has an online forum, and patient advocates who are actively in contact with patients and their families.
Group details last updated September 2017.
Information and support in the UK for families of children with Hallervordern-Spatz syndrome (pantothenate kinase-associated neurodegeneration) is provided by Climb (see entry Inherited Metabolic diseases).
McLeod syndrome
Also known as: McLeod Neuroacanthocytosis syndrome
McLeod syndrome is a rare inherited condition affecting adult males and involves the brain, neuromuscular system, blood, liver, spleen and heart. About five hundred cases have been reported.
- involuntary movements of the limbs, trunk, neck, face (lip and tongue biting are not typical)
- Parkinsonism
- nerve and muscle involvement
- heart problems
- enlarged liver and spleen
- mental health problems in about 20%
- seizures in about 40%
McLeod syndrome is caused by mutations of the XK gene on the X-chromosome.
By looking for the McLeod blood group phenotype (due to proteins on the red blood cells); confirmed by genetic analysis.
McLeod syndrome cannot be cured. Medications are given as needed for specific symptoms. Care must be taken if repeated blood transfusions are needed, as transfusion reactions can occur. Banking of the patient’s own blood is recommended.
Inheritance patterns
X-linked recessive.
Prenatal diagnosis
This may be possible in families already known to be affected. Affected families should be referred to their genetics service for further information and support.
Advocacy for Neuroacanthocytosis Patients
Tel: 020 7460 8874
Email: [email protected]
Website: naadvocacy.org
The Group is a Registered Charity in England and Wales No. 1133182. It provides information and support to neuroacanthocytosis patients and develops research aimed at alleviation of the disease. The Group has an online forum, and patient advocates who are actively in contact with patients and their families.
Group details last updated September 2017.
Information and support in the UK for families of children with Hallervordern-Spatz syndrome (pantothenate kinase-associated neurodegeneration) is provided by Climb (see entry Inherited Metabolic diseases).
