Huntington's Disease with Small CAG Repeat Expansions.
Mov Disord
; 38(7): 1294-1306, 2023 07.
Article
en En
| MEDLINE
| ID: mdl-37288993
ABSTRACT
BACKGROUND:
Carriers of small cytosine-adenine-guanine (CAG) repeats below 39 in the HTT gene are traditionally associated with milder Huntington's disease, but their clinical profile has not been extensively studied.OBJECTIVE:
To study the phenotype of CAG36-38 repeat carriers.METHODS:
We included 35 patients and premanifest carriers of CAG36-38 repeats. We compared clinical and neuropsychological profiles of 11 CAG36-38 patients with 11 matched CAG40-42 patients. In addition, we analyzed 243 CAG36-38 individuals from the ENROLL study to complete the phenotype description.RESULTS:
Global cognitive efficiency and performance in different cognitive subdomains were similar in small CAG36-38 and typically CAG40-42 expanded individuals. Chorea as the first symptom was significantly less frequent for CAG36-38 patients (P = 0.04) despite similar total motor scores at first visit. Total motor score at last visit was significantly lower in CAG36-38 carriers (P = 0.003). The similar cognitive and different motor profile of CAG36-38 (n = 243) and CAG40-42 (n = 4675) carriers was confirmed in the ENROLL database. Additionally, clinicians were significantly less confident in diagnosing Huntington's disease (P = 2.4e-8) and diagnosis happened significantly later in CAG36-38 (P = 2.2e-6) despite a similar age at symptom onset (P = 0.29).CONCLUSIONS:
We showed that small CAG36-38 expansion carriers had a similar cognitive profile to those with the more common CAG40-42 expansions. These individuals may evade molecular diagnosis because of the absence of chorea rather than because of a low penetrance of symptoms. This finding should encourage neurologists to consider Huntington's disease in cognitively impaired elderly patients without typical chorea and anticipate consequences for genetic counseling in their offspring. © 2023 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.Palabras clave
Texto completo:
1
Colección:
01-internacional
Banco de datos:
MEDLINE
Asunto principal:
Corea
/
Enfermedad de Huntington
Tipo de estudio:
Diagnostic_studies
Límite:
Humans
Idioma:
En
Revista:
Mov Disord
Asunto de la revista:
NEUROLOGIA
Año:
2023
Tipo del documento:
Article
País de afiliación:
Francia