title: Huntington Disease: Molecular Diagnostics Approach.
abstract: Huntington disease (HD) is caused by expansion of a CAG trinucleotide repeat in the first exon of the Huntingtin (HTT) gene. Molecular testing of Huntington disease for diagnostic confirmation and disease prediction requires detection of the CAG repeat expansion. There are three main types of HD genetic testing: (1) diagnostic testing to confirm or rule out disease, (2) presymptomatic testing to determine whether an at-risk individual inherited the expanded allele, and (3) prenatal testing to determine whether the fetus has inherited the expanded allele. This unit includes protocols that describe the complementary use of polymerase chain reactions (PCR) and Southern blot hybridization to accurately measure the CAG trinucleotide repeat size and interpret the test results. In addition, an indirect linkage analysis that does not reveal the unwanted parental HD status in a prenatal testing will also be discussed.
authors.affiliation: Neurogenetics DNA Diagnostic Laboratory, Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts.|Genetics Training Program, Harvard Medical School, Boston, Massachusetts.|Endocrine Unit, Department of Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts.
authors.forename: Murat
authors.initials: M
authors.lastname: Bastepe
authors.affiliation: Neurogenetics DNA Diagnostic Laboratory, Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts.|Center for Human Genetic Research, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts.
authors.forename: Winnie
authors.initials: W
authors.lastname: Xin
mesh_terms: D000483:Alleles; D015139:Blotting, Southern / Q000379:methods; D019075:Electrophoresis, Capillary / Q000379:methods; D006801:Humans; D000071058:Huntingtin Protein; D006816:Huntington Disease / Q000175:diagnosis* / Q000235:genetics*; D025202:Molecular Diagnostic Techniques; D009419:Nerve Tissue Proteins / Q000235:genetics; D016133:Polymerase Chain Reaction / Q000379:methods; D019680:Trinucleotide Repeat Expansion; D018911:Trinucleotide Repeats
chemical_list: C086055:HTT protein, human; D000071058:Huntingtin Protein; D009419:Nerve Tissue Proteins
keywords: HTT; Huntington disease; Huntington disease testing protocol; triplet repeat expansion