Premium
Factors associated with ATXN2 CAG/CAA repeat intergenerational instability in Spinocerebellar ataxia type 2
Author(s) -
AlmaguerMederos L.E.,
Mesa J.M.L.,
GonzálezZaldívar Y.,
AlmaguerGotay D.,
CuelloAlmarales D.,
AguileraRodríguez R.,
Falcón N.S.,
Gispert S.,
Auburger G.,
VelázquezPérez L.
Publication year - 2018
Publication title -
clinical genetics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.543
H-Index - 102
eISSN - 1399-0004
pISSN - 0009-9163
DOI - 10.1111/cge.13380
Subject(s) - spinocerebellar ataxia , genetics , locus (genetics) , allele , biology , cytosine , gene , genetic counseling , instability , physics , mechanics
Spinocerebellar ataxia type 2 (SCA2) is a neurodegenerative disorder caused by the unstable expansion of a cytosine‐adenine‐guanine (CAG)/cytosine‐adenine‐adenine (CAA) repeat in the ATXN2 gene, which normally encodes 22 glutamines (Q22). A large study was conducted to characterize the CAG/CAA repeat intergenerational instability in SCA2 families. Large normal alleles (Q24‐31) were significantly more unstable upon maternal transmissions. In contrast, expanded alleles (Q32‐750) were significantly more unstable during paternal transmissions, in correlation with repeat length. Significant correlations were found between the instability and the age at conception in paternal transmissions. In conclusion, intergenerational instability at ATXN2 locus is influenced by the sex, repeat length and age at conception of the transmitting parent. These results have profound implications for genetic counseling services.