Predicting Disease Onset from Mutation Status Using Proband and Relative Data with Applications to Huntington's Disease

Huntington's disease (HD) is a progressive neurodegenerative disorder caused by an expansion of CAG repeats in the IT15 gene. The age-at-onset (AAO) of HD is inversely related to the CAG repeat length and the minimum length thought to cause HD is 36. Accurate estimation of the AAO distribution...

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Main Authors: Tianle Chen, Yuanjia Wang, Yanyuan Ma, Karen Marder, Douglas R. Langbehn
Format: Article
Language:English
Published: Wiley 2012-01-01
Series:Journal of Probability and Statistics
Online Access:http://dx.doi.org/10.1155/2012/375935
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author Tianle Chen
Yuanjia Wang
Yanyuan Ma
Karen Marder
Douglas R. Langbehn
author_facet Tianle Chen
Yuanjia Wang
Yanyuan Ma
Karen Marder
Douglas R. Langbehn
author_sort Tianle Chen
collection DOAJ
description Huntington's disease (HD) is a progressive neurodegenerative disorder caused by an expansion of CAG repeats in the IT15 gene. The age-at-onset (AAO) of HD is inversely related to the CAG repeat length and the minimum length thought to cause HD is 36. Accurate estimation of the AAO distribution based on CAG repeat length is important for genetic counseling and the design of clinical trials. In the Cooperative Huntington's Observational Research Trial (COHORT) study, the CAG repeat length is known for the proband participants. However, whether a family member shares the huntingtin gene status (CAG expanded or not) with the proband is unknown. In this work, we use the expectation-maximization (EM) algorithm to handle the missing huntingtin gene information in first-degree family members in COHORT, assuming that a family member has the same CAG length as the proband if the family member carries a huntingtin gene mutation. We perform simulation studies to examine performance of the proposed method and apply the methods to analyze COHORT proband and family combined data. Our analyses reveal that the estimated cumulative risk of HD symptom onset obtained from the combined data is slightly lower than the risk estimated from the proband data alone.
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spelling doaj-art-7702cf7245524fe5aace4a4a4c32c07a2025-02-03T06:12:09ZengWileyJournal of Probability and Statistics1687-952X1687-95382012-01-01201210.1155/2012/375935375935Predicting Disease Onset from Mutation Status Using Proband and Relative Data with Applications to Huntington's DiseaseTianle Chen0Yuanjia Wang1Yanyuan Ma2Karen Marder3Douglas R. Langbehn4Department of Biostatistics, Mailman School of Public Health, Columbia University, 722 West 168th Street, New York, NY 10032, USADepartment of Biostatistics, Mailman School of Public Health, Columbia University, 722 West 168th Street, New York, NY 10032, USADepartment of Statistics, Texas A&M University, College Station, TX 77843, USADepartments of Neurology and Psychiatry and Sergievsky Center and the Taub Institute, Columbia University Medical Center, New York, NY 10032, USADepartment of Psychiatry and Biostatistics (Secondary), University of Iowa, Iowa City, IA 52242, USAHuntington's disease (HD) is a progressive neurodegenerative disorder caused by an expansion of CAG repeats in the IT15 gene. The age-at-onset (AAO) of HD is inversely related to the CAG repeat length and the minimum length thought to cause HD is 36. Accurate estimation of the AAO distribution based on CAG repeat length is important for genetic counseling and the design of clinical trials. In the Cooperative Huntington's Observational Research Trial (COHORT) study, the CAG repeat length is known for the proband participants. However, whether a family member shares the huntingtin gene status (CAG expanded or not) with the proband is unknown. In this work, we use the expectation-maximization (EM) algorithm to handle the missing huntingtin gene information in first-degree family members in COHORT, assuming that a family member has the same CAG length as the proband if the family member carries a huntingtin gene mutation. We perform simulation studies to examine performance of the proposed method and apply the methods to analyze COHORT proband and family combined data. Our analyses reveal that the estimated cumulative risk of HD symptom onset obtained from the combined data is slightly lower than the risk estimated from the proband data alone.http://dx.doi.org/10.1155/2012/375935
spellingShingle Tianle Chen
Yuanjia Wang
Yanyuan Ma
Karen Marder
Douglas R. Langbehn
Predicting Disease Onset from Mutation Status Using Proband and Relative Data with Applications to Huntington's Disease
Journal of Probability and Statistics
title Predicting Disease Onset from Mutation Status Using Proband and Relative Data with Applications to Huntington's Disease
title_full Predicting Disease Onset from Mutation Status Using Proband and Relative Data with Applications to Huntington's Disease
title_fullStr Predicting Disease Onset from Mutation Status Using Proband and Relative Data with Applications to Huntington's Disease
title_full_unstemmed Predicting Disease Onset from Mutation Status Using Proband and Relative Data with Applications to Huntington's Disease
title_short Predicting Disease Onset from Mutation Status Using Proband and Relative Data with Applications to Huntington's Disease
title_sort predicting disease onset from mutation status using proband and relative data with applications to huntington s disease
url http://dx.doi.org/10.1155/2012/375935
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