All Children's Hospital Logo

Huntington Disease


Molecular Genetics Clinical Laboratory- Huntington Disease

INDICATIONS FOR TESTING:
Huntington disease (HD) is a slowly progressive disease involving emotional distress, involuntary movements and progressive mental and physical incapacitation affected 1/10,000 persons. HD is inherited in an autosomal dominant manner, with each child of an affected person having a 50 percent risk of inheriting HD. Both males and females are equally at risk. The average age of the onset of symptoms is 35 to 45 years and the average disease course is 15 to 20 years. Although a "typical" form of the disease is often described, there is considerable variation in severity between families. There is also variation in severity within families, especially if transmission is through affected males, occasionally resulting in juvenile-onset or childhood-onset HD.

TESTING OFFERED:
Approximately 99% of affected individuals have an expansion of a trinucleotide CAG repeat pattern in the huntington gene localized to chromosome 4p1.6 that can be accurately measured. The repeat length is up to 25 in normal individuals, and from 39 to over 100 in affected persons. Individuals with repeats between 25 and 34 have not been found with symptoms of HD, although some variable symptoms have been reported for repeat lengths from 35 to 39. However, these intermediate repeat lengths from 25 to 39 have been shown to be unstable and their children are at increased risk for HD.

TURN-AROUND TIME:
Most testing is completed within a time of 21 days following specimen receipt. Prenatal testing is usually completed within 7 days from specimen receipt.

TESTING REQUIREMENTS:
Molecular testing for HD is based on the protocol established by the Huntington Disease Society of America.

Presymptomatic Adults:
Adult at 50% risk are tested in conjunction with personal genetic counseling, psychological screening and possibly neurological evaluation.

Symptomatic Adults:
Specimens of 4 cc whole blood in EDTA tubes are accepted from symptomatic adults under the care of neurologists following counseling and informed consent.

Children:
Specimens from minors are not accepted in the absence of clinical symptoms.

COST:
The cost of testing is available upon request.

FOR MORE INFORMATION, PLEASE CONTACT:
Phone:
(727) 767-8985 (Laboratory)
            (727) 767-8611 (Director)
Fax: (727) 767-8367
E-mail: omuelle1@jhmi.edu

 


Related Information

Pathology & Laboratory Medicine
Physician Directory
Related Pages

Additional Info

Pocket Doc Mobile App
Maps and Locations (Mobile)
Programs & Services
Employment
For Health Professionals
For Patients & Families
Contact Us
Find a Doctor
News
CME

All Children's Hospital
501 6th Ave South
St. Petersburg, FL 33701
(727) 898-7451
(800) 456-4543

Use Normal Template
© 2014 All Children's Hospital - All Rights Reserved