Ainhi D Ha1, Joseph Jankovic. 1. Parkinson's Disease Center and Movement Disorders Clinic, Department of Neurology, Baylor College of Medicine, Houston, TX 77030, USA.
Abstract
OBJECTIVE: To explore the clinical phenotype in individuals with huntingtin gene CAG repeat lengths between 27 and 35, a range that is termed "intermediate" and below one traditionally considered diagnostic of Huntington disease (HD). BACKGROUND: The Prospective Huntington Disease At-Risk Observational Study (PHAROS) found that patients with intermediate CAG lengths overlapped with those diagnosed as HD (≥ 37 CAG repeats) on the Unified Huntington's Disease Rating Scale (UHDRS) behavioral measures. Furthermore, several patients with intermediate CAG repeats demonstrating clinical (and pathological) evidence of HD have been reported. METHODS: We reviewed all cases with intermediate CAG repeats who have presented to our clinic, as well as those reported in the literature. RESULTS: We describe 4 patients with intermediate repeats evaluated at our center whose clinical features were highly suggestive of HD. Investigations for HD phenocopies were negative. Anticipation was demonstrated in 1 case with supportive neuropathological evidence of HD. Additionally, we describe the clinical features of 5 other patients reported in the literature. CONCLUSION: Individuals with huntingtin gene CAG repeats in the intermediate (27-35) range should be considered at risk for the development of HD, particularly if they have a family history of HD, whether they exhibit clinical features of the disease.
OBJECTIVE: To explore the clinical phenotype in individuals with huntingtin gene CAG repeat lengths between 27 and 35, a range that is termed "intermediate" and below one traditionally considered diagnostic of Huntington disease (HD). BACKGROUND: The Prospective Huntington Disease At-Risk Observational Study (PHAROS) found that patients with intermediate CAG lengths overlapped with those diagnosed as HD (≥ 37 CAG repeats) on the Unified Huntington's Disease Rating Scale (UHDRS) behavioral measures. Furthermore, several patients with intermediate CAG repeats demonstrating clinical (and pathological) evidence of HD have been reported. METHODS: We reviewed all cases with intermediate CAG repeats who have presented to our clinic, as well as those reported in the literature. RESULTS: We describe 4 patients with intermediate repeats evaluated at our center whose clinical features were highly suggestive of HD. Investigations for HD phenocopies were negative. Anticipation was demonstrated in 1 case with supportive neuropathological evidence of HD. Additionally, we describe the clinical features of 5 other patients reported in the literature. CONCLUSION: Individuals with huntingtin gene CAG repeats in the intermediate (27-35) range should be considered at risk for the development of HD, particularly if they have a family history of HD, whether they exhibit clinical features of the disease.
Authors: Annie Killoran; Kevin M Biglan; Joseph Jankovic; Shirley Eberly; Elise Kayson; David Oakes; Anne B Young; Ira Shoulson Journal: Neurology Date: 2013-04-26 Impact factor: 9.910
Authors: Marianne O Klein; Daniella S Battagello; Ariel R Cardoso; David N Hauser; Jackson C Bittencourt; Ricardo G Correa Journal: Cell Mol Neurobiol Date: 2018-11-16 Impact factor: 5.046