Double deletions and missense mutations in the first nucleotide-binding fold of the ATP-binding cassette transporter A1 (ABCA1) gene in Japanese patients with Tangier disease

Tangier disease (TD) is a rare autosomal recessive disease characterized by plasma high-density lipoprotein deficiency caused by an ATP-binding cassette transporter A1 (ABCA1) gene mutation. We describe three different mutations in Japanese patients with TD. The first patient was homozygous for double deletions of 1221 bp between intron 12 and 14 and 19.9 kb between intron 16 and 31. The breakpoint sequence analyses suggest that it is a simultaneous event caused by double-loop formation through multiple Alu. The second patient was homozygous for a novel mutation of A3198C in exon 19, resulting in Asn935His. The third patient was homozygous for A3199G of exon 19 that leads to Asn935Ser, which is the same mutation found in German and Spanish families. Both Asn mutations involved Walker A motif of the first nucleotide-binding fold.