AUTHOR=Liu Chaorong , Song Yanmin , Yuan Ying , Peng Ying , Pang Nan , Duan Ranhui , Huang Wen , Qin Xuehui , Xiao Wenbiao , Long Hongyu , Huang Sha , Zhou Pinting , Long Lili , Xiao Bo 

TITLE=TTTCA Repeat Expansion of SAMD12 in a New Benign Adult Familial Myoclonic Epilepsy Pedigree

JOURNAL=Frontiers in Neurology

VOLUME=Volume 11 - 2020

YEAR=2020

URL=https://www.frontiersin.org/journals/neurology/articles/10.3389/fneur.2020.00068

DOI=10.3389/fneur.2020.00068

ISSN=1664-2295

ABSTRACT=Benign adult familial myoclonic epilepsy (BAFME) is an autosomal dominant disorder characterized by adult-onset cortical myoclonus with or without seizures. Recently, it was reported to be associated with an intronic TTTTA/TTTCA expansions. To investigate whether these abnormal expansions are involved in our new pedigree from China, whole exome sequencing (WES) and repeat-primed polymerase chain reaction (RP-PCR) analysis were performed to detect potential mutation in pedigree members. Neither causal mutations co-segregated with the disease in the family nor any novel mutation was identified through WES. While an abnormal TTTCA expansion in SAMD12 was identified by RP-PCR and then proved to be co-segregated in the pedigree. All the 12 alive affected individuals (M/F = 4/8; average age = 46.7 years old, range from 27 to 66) showed typical characteristics of BAFME. In addition, maternal clinical anticipation was observed in six mother/child pairs. In conclusion, our study offered the evidence of intronic pentanucleotide expansions in SAMD12 from a new Chinese BAFME pedigree, which further confirmed the association between this expansion and the pathogenesis of BAFME.