Open AccessAnalysis of unstable DNA sequence in FMR1 gene in Polish families with fragile X syndrome.
Author(s) -
Michał Milewski,
Marta Zygulska,
Jerzy Bal,
Wout H. Deelen,
Ewa Obersztyn,
Ewa Bocian,
Dicky Halley,
Jürgen Horst,
Tadeusz Mazurczak
Publication year - 1996
Publication title -
acta biochimica polonica
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.452
H-Index - 78
eISSN - 1734-154X
pISSN - 0001-527X
DOI - 10.18388/abp.1996_4508
Subject(s) - fragile x syndrome , genetics , allele , fmr1 , biology , gene , mutation , sequence (biology) , repeated sequence , fragile x , chromosomal fragile site , microbiology and biotechnology , genome , chromosome
The unstable DNA sequence in the FMR1 gene was analyzed in 85 individuals from Polish families with fragile X syndrome in order to characterize mutations responsible for the disease in Poland. In all affected individuals classified on the basis of clinical features and expression of the fragile site at X(q27.3) a large expansion of the unstable sequence (full mutation) was detected. About 5% (2 of 43) of individuals with full mutation did not express the fragile site. Among normal alleles, ranging in size from 20 to 41 CGG repeats, allele with 29 repeats was the most frequent (37%). Transmission of premutated and fully mutated alleles to the offspring was always associated with size increase. No change in repeat number was found when normal alleles were transmitted.