CONICET | Buscador de Institutos y Recursos Humanos

Introduction: Severe deficiency of ADAMTS13 may cause thrombotic thrombocytopenic purpura (TTP). Mutations in the ADAMTS13 gene have been causatively linked to hereditary TTP. There are evidences that single nucleotide polymorphisms (SNPs) influence ADAMTS13 activity levels. The aim of our ongoing study is to describe three new SNPs located in intron 2.Severe deficiency of ADAMTS13 may cause thrombotic thrombocytopenic purpura (TTP). Mutations in the ADAMTS13 gene have been causatively linked to hereditary TTP. There are evidences that single nucleotide polymorphisms (SNPs) influence ADAMTS13 activity levels. The aim of our ongoing study is to describe three new SNPs located in intron 2. Methods: We studied patients with thrombotic microangiopathy (TMA), all with ADAMTS13 deficiency (P1-P9), P8 and P9 with circulating inhibitory ADAMTS13 antibody. P1's parents and three normal controls were studied. Coding regions, intron/exon boundaries and 5' and 3' regions of exon 3 of ADAMTS13 gene was amplified in all samples. Exons 5, 6, 9, 12, 15, 20, 21, 25-29 of ADAMTS13 gene were also amplified in P1. Sequence analysis of DNA fragments was performed with the use of a DYEnamic ET Terminator Cycle Sequencing Kit. Automated sequencing of PCR fragments was performed on an ABI Prism 310 Genetic Analyzer.We studied patients with thrombotic microangiopathy (TMA), all with ADAMTS13 deficiency (P1-P9), P8 and P9 with circulating inhibitory ADAMTS13 antibody. P1's parents and three normal controls were studied. Coding regions, intron/exon boundaries and 5' and 3' regions of exon 3 of ADAMTS13 gene was amplified in all samples. Exons 5, 6, 9, 12, 15, 20, 21, 25-29 of ADAMTS13 gene were also amplified in P1. Sequence analysis of DNA fragments was performed with the use of a DYEnamic ET Terminator Cycle Sequencing Kit. Automated sequencing of PCR fragments was performed on an ABI Prism 310 Genetic Analyzer. Results: Studies in intron 2: a) SNPs G173-18T was found in P1 and his father (homozygous), P1's mother and P8 (heterozygous). b) SNPs G173-48A was identified in P1 and his father (homozygous), P1's mother, P2 and P8 (heterozygous). c) SNPs G173-67C was found in P1 and his father, P2, P4-P8, and two normal controls (homozygous), P1's mother, P9 and a normal control (heterozygous). No mutations or SNPs were identified in exons 5, 6, 9, 12, 15, 20, 21, 25-29 of ADAMTS13 gene of patient 1.Studies in intron 2: a) SNPs G173-18T was found in P1 and his father (homozygous), P1's mother and P8 (heterozygous). b) SNPs G173-48A was identified in P1 and his father (homozygous), P1's mother, P2 and P8 (heterozygous). c) SNPs G173-67C was found in P1 and his father, P2, P4-P8, and two normal controls (homozygous), P1's mother, P9 and a normal control (heterozygous). No mutations or SNPs were identified in exons 5, 6, 9, 12, 15, 20, 21, 25-29 of ADAMTS13 gene of patient 1. Conclusions: Recent findings provided evidence that common SNPs may differently modulate ADAMTS13 function in addition to its protease levels, and some SNPs combinations (on a single allele) may produce the absence of ADAMTS13 secretion. We reported three new SNPs (G173-18T, G173-48A and G173-67C) in intron 2. Their significance, alone or in combination is uncertain. This consideration is reinforced by the finding of normal ADAMTS13 activity in P1's father.Recent findings provided evidence that common SNPs may differently modulate ADAMTS13 function in addition to its protease levels, and some SNPs combinations (on a single allele) may produce the absence of ADAMTS13 secretion. We reported three new SNPs (G173-18T, G173-48A and G173-67C) in intron 2. Their significance, alone or in combination is uncertain. This consideration is reinforced by the finding of normal ADAMTS13 activity in P1's father.