|
| Family-HD Underestimated |
|
|
|
|
Family history and DNA analysis in patients
with suspected Huntington's disease S Siesling, M Vegter-van de Vlis, M Losekoot, R D M Belfroid, J A Maat-Kievit,H P H Kremer, and R A C Roos J Neurol Neurosurg Psychiatry 2000 69: 54-59 Read Full Text of Article: http://jnnp.bmjjournals.com/cgi/content/full/69/1/54
ABSTRACT
OBJECTIVES Until recently a definite diagnosis of Huntington's disease could be
made by a combination of clinical findings, a positive family history,
and pathological confirmation. Prevalence data are based on these
criteria. After finding the gene and its pathogenic mutation direct
diagnostic confirmation became available.
The aim of this study was to determine to what extent the direct
assessment of CAG repeat length has allowed the diagnoses of additional
patients, with atypical psychiatric or neurological disease, or those
without a family history, that could otherwise not be diagnosed using
traditional criteria.
PATIENTS AND METHODS
From all 191 referred patients suspected of having Huntington's disease
between July 1993 and January 1996 CAG repeat length was determined
and the family history was reviewed in the Leiden roster. After a retro-
spective search the patients were subdivided in positive, negative,
suspect, and unknown family histories. Patients with an expanded repeat
(>35) were finally diagnosed as having Huntington's disease. The family
history was compared with the repeat length and the clinical features.
RESULTS
Clinical information was obtained for 172 patients. Of these, 126 patients
had an expanded repeat, 77 had a positive, eight a negative, 40 a suspect,
and one an unknown family history. Of the 44 patients with a normal repeat
length four had a positive family history. Of the two patients with an
intermediate repeat (between 30-36 repeats), one with a negative family
history received a clinical diagnosis of Gilles de la Tourette's syndrome. The
other had an unknown family history.
CONCLUSION
Despite verification of the family history through the Leiden roster, many
more patients and families could be diagnosed with the new approach than
would have been possible with the traditional criteria. Because prevalence
studies have been based on this type of information, the data suggest an
underestimation of the prevalence of Huntington's disease in the community
of 14%.
(J Neurol Neurosurg Psychiatry 2000;69:54-59) |
|
|
|
|
|
| | |
|
|
|
| | |
|
|
|  | |
|
|
| | |
|
|
|