Two novel mutations consisting in minor gene rearrangements in the human low density lipoprotein receptor gene in Italian patients affected by familial hypercholesterolemia. Mutations in brief no. 194. Online.

Mutations in the low density lipoprotein (LDL)-receptor gene cause familial hypercholesterolemia (FH), an autosomal dominant disease associated to an increased risk of premature atherosclerosis. We describe two novel mutations found in Italian families and consisting in minor gene rearrangements. The first one (FH-Pisa) is a tetranucleotide insertion occurring in exon 8, which causes a frameshift and a premature stop codon. The second one (FH-Chieti3) occurs at the 3'-end of exon 4 and consists in a trinucleotide deletion replaced by a six-base insertion, so that the reading frame is maintained with a glutamic acid-to-cysteine substitution at codon 207 and the insertion of a lysine at codon 208. Both mutations occur in regions of the LDL-receptor gene which can be considered hotspots for minor rearrangements.