Genomic characterization of large rearrangements of the LDLR gene in Czech patients with familial hypercholesterolemia.
BACKGROUND
Mutations in the LDLR gene are the most frequent cause of Familial hypercholesterolemia, an autosomal dominant disease characterised by elevated concentrations of LDL in blood plasma. In many populations, large genomic rearrangements account for approximately 10% of mutations in the LDLR gene.


METHODS
DNA diagnostics of large genomic rearrangements was based on Multiple Ligation dependent Probe Amplification (MLPA). Subsequent analyses of deletion and duplication breakpoints were performed using long-range PCR, PCR, and DNA sequencing.


RESULTS
In set of 1441 unrelated FH patients, large genomic rearrangements were found in 37 probands. Eight different types of rearrangements were detected, from them 6 types were novel, not described so far. In all rearrangements, we characterized their exact extent and breakpoint sequences.


CONCLUSIONS
Sequence analysis of deletion and duplication breakpoints indicates that intrachromatid non-allelic homologous recombination (NAHR) between Alu elements is involved in 6 events, while a non-homologous end joining (NHEJ) is implicated in 2 rearrangements. Our study thus describes for the first time NHEJ as a mechanism involved in genomic rearrangements in the LDLR gene.
Goldmann
Radan
R
University Hospital Brno, Centre of Molecular Biology and Gene Therapy, Cernopolní 9, CZ-62500 Brno, Czech Republic.
Tichý
Lukás
L
Freiberger
Tomás
T
Zapletalová
Petra
P
Letocha
Ondrej
O
Soska
Vladimír
V
Fajkus
Jirí
J
Fajkusová
Lenka
L
D020087:Alu Elements; D001483:Base Sequence; D018153:Czech Republic; D015321:Gene Rearrangement; D006801:Humans; D006938:Hyperlipoproteinemia Type II / Q000235:genetics*; D008969:Molecular Sequence Data; D011973:Receptors, LDL / Q000235:genetics*
D011973:Receptors, LDL