Presymptomatic testing in Huntington's disease and autosomal dominant cerebellar ataxias.
OBJECTIVE
To report a 7-year experience of presymptomatic testing in persons at risk for Huntington disease (HD) and to compare their characteristics and outcomes with those of persons at risk for a less disabling condition, autosomal dominant cerebellar ataxias (ADCA).


METHODS
The authors collected data on presymptomatic testing for HD (n = 712) and ADCA (n = 46) in 10 French centers.


RESULTS
The characteristics of applicants were similar in HD and ADCA, revealing a predominance of women, a low rate of completing the presymptomatic testing program, and a high rate of follow-up. The frequency of serious events was low (2% for HD, 5% for ADCA), but such events were also found after favorable results. Family planning was a more frequent reason for seeking presymptomatic testing in ADCA than in HD. Prenatal diagnosis was performed in only half of the pregnancies in HD carriers (n = 35) but in all of those in ADCA carriers (n = 4).


CONCLUSIONS
Counseling in multistep and multidisciplinary teams is important not only for presymptomatic testing in HD but also for less disabling diseases.
Goizet
C
C
Service de Génétique Médicale, Hôpital Pellegrin-Enfants, Bordeaux, France.
Lesca
G
G
Dürr
A
A
D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D000368:Aged; D002524:Cerebellar Ataxia / Q000175:diagnosis* / Q000453:epidemiology / Q000235:genetics*; D005260:Female; D005602:France; D005799:Genes, Dominant; D005820:Genetic Testing / Q000523:psychology / Q000706:statistics & numerical data*; D006801:Humans; D006816:Huntington Disease / Q000175:diagnosis* / Q000453:epidemiology / Q000235:genetics*; D008297:Male; D008875:Middle Aged; D010342:Patient Acceptance of Health Care / Q000523:psychology / Q000706:statistics & numerical data; D012307:Risk Factors; D017678:Sex Distribution; D012923:Social Class