title: Large pathogenic expansions in the SCA2 and SCA7 genes can be detected by fluorescent repeat-primed polymerase chain reaction assay.
abstract: Large expansions in the SCA2 and SCA7 genes (>100 CAG repeats) have been associated with juvenile and infantile forms of cerebellar ataxias that cannot be detected using standard polymerase chain reaction (PCR). Here, we describe a successful application of the fluorescent short tandem repeat-primed PCR method for accurate identification of these expanded repeats. The test is robust, reliable, and inexpensive and can be used to screen large series of patients, although it cannot give a precise evaluation of the size of the expansion. This test may be of practical value in prenatal diagnoses offered to affected or pre-symptomatic at-risk parents, in which a very large expansion inherited from one of the parents can be missed in the fetus by standard PCR.
authors.affiliation: Dipartimento di Genetica Biologia e Biochimica, Università degli Studi di Torino, via Santena 19, 10126, Torino, Italy.
authors.forename: Claudia
authors.initials: C
authors.lastname: Cagnoli
authors.forename: Giovanni
authors.initials: G
authors.lastname: Stevanin
authors.forename: Chiara
authors.initials: C
authors.lastname: Michielotto
authors.forename: Giovanni
authors.initials: G
authors.lastname: Gerbino Promis
authors.forename: Alessandro
authors.initials: A
authors.lastname: Brussino
authors.forename: Patrizia
authors.initials: P
authors.lastname: Pappi
authors.forename: Alexandra
authors.initials: A
authors.lastname: Durr
authors.forename: Elisa
authors.initials: E
authors.lastname: Dragone
authors.forename: Michelle
authors.initials: M
authors.lastname: Viemont
authors.forename: Cinzia
authors.initials: C
authors.lastname: Gellera
authors.forename: Alexis
authors.initials: A
authors.lastname: Brice
authors.forename: Nicola
authors.initials: N
authors.lastname: Migone
authors.forename: Alfredo
authors.initials: A
authors.lastname: Brusco
mesh_terms: D000067719:Ataxin-7; D000067528:Ataxins; D016022:Case-Control Studies; D005453:Fluorescence; D006580:Genetic Carrier Screening; D005820:Genetic Testing; D006801:Humans; D009419:Nerve Tissue Proteins / Q000235:genetics* / Q000378:metabolism; D016133:Polymerase Chain Reaction / Q000379:methods*; D013132:Spinocerebellar Degenerations / Q000175:diagnosis* / Q000235:genetics; D019680:Trinucleotide Repeat Expansion / Q000235:genetics*
chemical_list: C000593829:ATXN7 protein, human; D000067719:Ataxin-7; D000067528:Ataxins; D009419:Nerve Tissue Proteins