Related Disorders List

Information on the following diseases can be found in the Related Disorders section of this report:

• Acanthocytosis
• Huntington's Disease
• Sydenham's Chorea
• Tourette Syndrome
• Wilson's Disease

Symptoms

Symptoms of Neuroacanthocytosis usually begin in early adult life. Abnormal red blood cells (acanthocytosis) with normal lipoproteins, as well as atrophy of muscles and uncontrolled movements of the face and body (amyotrophic chorea) are the two major symptoms of this disorder.

Neuroacanthocytosis starts with subtle involuntary movements (tics) of the face, mouth and tongue and slowly progresses to severe, uncontrolled, rapid motions (chorea) of the trunk and limbs. Jerking movements (dyskinesia) of the mouth, tongue and face become apparent along with tongue, cheek and lip biting. Tendon reflexes are absent. Personality changes as well as comprehension, judgement, memory and reasoning (cognitive) deficits are seen in over half of the cases. Muscle weakness and atrophy eventually affect the arms, legs and trunk. Approximately half of the affected patients have seizures.

Parkinsonism (a nervous system disorder causing tremors, rigid muscles, mild paralysis, and difficulty in chewing, swallowing and speaking) has been found in association with Neuroacanthocytosis in some patients.

Mild to moderate mental deterioration has been found in a significant proportion of individuals with Neuroacanthocytosis.

Causes

Neuroacanthocytosis is a very rare disorder usually inherited as an autosomal recessive genetic trait. However, the medical literature documents one family that may have inherited the disorder as an autosomal dominant genetic trait.

Human traits, including the classic genetic diseases, are the product of the interaction of two genes, one received from the father and one from the mother.

In dominant disorders, a single copy of the disease gene (received from either the mother or father) will be expressed "dominating" the other normal gene and resulting in the appearance of the disease. The risk of transmitting the disorder from affected parent to offspring is 50 percent for each pregnancy regardless of the sex of the resulting child.

In recessive disorders, the condition does not appear unless a person inherits the same defective gene for the same trait from each parent. If an individual receives one normal gene and one gene for the disease, the person will be a carrier for the disease, but usually will not show symptoms. The risk of transmitting the disease to the children of a couple, both of whom are carriers for a recessive disorder, is 25 percent. Fifty percent of their children risk being carriers of the disease, but generally will not show symptoms of the disorder. Twenty-five percent of their children may receive both normal genes, one from each parent, and will be genetically normal (for that particular trait). The risk is the same for each pregnancy.

Affected Populations

Neuroacanthocytosis affects males and females in equal numbers and has been found in the United States, Japan, Great Britain and Finland.

Related Disorders

Symptoms of the following disorders can be similar to those of Neuroacanthocytosis. Comparisons may be useful for a differential diagnosis:

Acanthocytosis (Abetalipoproteinemia) is a rare disorder that is characterized by the absence of very low density lipoproteins (VLDL) and chylamicrons in the plasma, and fat malabsorption resulting in excessive fat excretion (steatorrhea). Other symptoms include abnormal red blood cells (acanthocytes), impaired muscle coordination (ataxia), and a visual disorder (retinitis pigmentosa). This disorder is inherited as an autosomal recessive genetic trait. (For more information on this disorder, choose "Acanthocytosis" as your search term in the Rare Disease Database.)

Huntington's Disease is a progressive degenerative neurological disorder that typically appears between the ages of thirty and fifty. Those affected may experience involuntary movements, loss of motor control, changes in gait, loss of memory, and eventual loss of both mental capability and physical control. This disorder is inherited as an autosomal dominant genetic trait. (For more information on this disorder choose "Huntington" as your search term in the Rare Disease Database.)

Sydenham's Chorea is a non-progressive neurological movement disorder characterized by uncontrollable muscle spasms of the face and limbs. This disorder typically begins with jerky, uncontrollable, nonrepetitive muscle movements on one or both sides of the body. There may be facial contortions, grunting, difficulty in speaking and impaired coordination. This disorder is caused by a streptococcal infection. (For more information on this disorder, choose "Sydenham" as your search term in the Rare Disease Database.)

Tourette Syndrome is a rare neurological movement disorder that typically begins in childhood between the ages of two and sixteen. This disease is characterized by involuntary muscular movements, tics, and incontrollable vocal sounds. The disorder is not degenerative. Symptoms wax and wane, sometimes disappearing only to be replaced by new tics. Tourette Syndrome is thought to be inherited as an autosomal dominant genetic trait. (For more information on this disorder, choose "Tourette" as your search term in the Rare Disease Database.)

Wilson's Disease is a rare disorder characterized by excess storage of copper in the body tissues. This eventually leads to central nervous system dysfunction, liver disease and a rusty-brown colored ring in the cornea of each eye (Kayser-Fleischer ring). The most common symptoms of Wilson's Disease may be incoordination, tremor, slurred speech, drooling, difficulty in chewing and swallowing, spastic movements, lack of balance, muscle rigidity, and double vision. (For more information on this disorder, choose "Wilson" as your search term in the Rare Disease Database.)

Standard Therapies

Some patients with Neuroacanthocytosis may benefit from dopamine-blocking drugs such as haloperidol which is used for treatment of chorea.

Patients with seizures may benefit from treatment with anti-convulsant drugs such as phenytoin, valproic acid, phenobarbitol, clonazepam, ethusuximide, primidone, corticotropin, and corticosteroid drugs.

Genetic counseling may be of benefit for patients and their families. Other treatment is symptomatic and supportive.

Investigational Therapies

Research on genetic disorders and their causes is ongoing. The National Institutes of Health (NIH) is sponsoring the Human Genome Project which is aimed at mapping every gene in the human body and learning why they sometimes malfunction. It is hoped that this new knowledge will lead to prevention and treatment of genetic disorders in the future.

References

McKusick VA., ed. Online Mendelian Inheritance in Man (OMIM). Baltimore, MD: Johns Hopkins University Press; Entry No: 100500, Creation Date: 6/4/86, Last Edit Date: 6/1/98.

TEXTBOOKS
Buyse ML, ed., Birth Defects Encyclopedia. Dover, MA: Blackwell Scientific Publications; for Center for Birth Defects Information Services, Inc; 1990:4-5.

Palek J, Jarolim P. Red cell membrane disorders. In: Hoffman R, et al., eds. Hematology. 2nd ed. New York, NY: Churchill Livinstone, Inc; 1995:690-95.

REVIEW ARTICLE
Rafalowski J, et al., Review of literature and case report. Folia Neuropathol. 1996;34:178-83.

JOURNAL ARTICLES
Aasly J, et al., Neuroacanthocytosis--the variability of presenting symptoms in two siblings. acta Neurol Scand. 1999;100:322-25.

Kutcher JS, et al., Neuroacanthocytosis masquerading as Huntington’s disease: CT/MRI findings. J Neuroimaging. 1999;9:187-89.

Bohlega S, et al., Neuroacanthocytosis and aprebetalipoproteinemia. Neurology. 1998;50:1912-14.

Okamoto K, et al., CT and MR findings of neuroacanthocytosis. J Comput Assist Tomogr. 1997;21:221-22.

Rubio JP, et al., Chorea acanthocytosis: genetic linkage to chromosome 9q21. Am J Hum Genet. 1997;61:899-908.

INTERNET:
http://www.ninds.nih.gov/disorders/neuroacanthocytosis/neuroacanthocytosis.htm?css=print

eMedicine - Neuroacanthocytosis : Article by Eric Dinnerstein, MD