Search

Transthyretin gene mutations are associated with autosomal dominant familial amyloidosis. The commonest phenotype in the patients is peripheral neuropathy, but restrictive cardiomyopathy is also a frequent sign. More than 70 different mutations in the gene have been described. Although these mutations are randomly distributed, some hot spots have also been reported notably at position 6, 30, 33, 58, 109, 119 and 122. A few of these codons contain a CpG dinucleotide. We describe an additional ‘hot spot’ occurring at codon 47, in which we report one novel and two previously described mutations. This codon, however, does not contain a CpG dinucleotide, suggesting that other mechanisms might be responsible for the allelic heterogeneity. All the reported mutations in codon 47 are located in the exon 2 consensus sequence and are potentially involved in splicing. We performed transcription analysis on two livers obtained from transplanted patients carrying the Ala47 mutation. These livers showed a normally spliced message, indicating that this mutation does not affect splicing. [ABSTRACT FROM AUTHOR]

HTIF1α, a transcription coactivator which is able to mediate RAR3 activity and functionally interact with PML, is encoded by a gene on chromosome 7q32-34, which is a critical region in acute myeloid leukemias (AML). With the assumption that this gene may be related to AML, we investigated the HTIF1α DNA structure and RNA expression in leukemic cells from 36 M1-M5 AML patients (28 'de novo' and eight 'secondary' to myelodysplastic syndrome (MDS)). Abnormal HTIF1α DNA fragments were never found, whereas loss of HTIF1α DNA was observed in the patients with chromosome 7q32 deletion and translocation, and in one case without detectable chromosome 7 abnormality. HTIF1α RNA was found in acute myelocytic leukemic blasts, and was almost undetectable in normal mono-nuclear cells. The expression varied among the patients: higher in M1 to M3 subtypes, with the highest values in M1; low levels were constantly observed in M4 and M5 AML. In addition, HTIF1α was significantly overexpressed in MDS-related AML (MDR-AML), but not in MDS. We also found that HTIF1α expression was high in myeloid cell lines. In myeloblastic HL60 and promyelocytic NB4 cells, induced to differentiate along the monocytic -- macrophage pathway by TPA or vitamin D3, HTIF1α expression decreased, whereas it was maintained at high levels on induction to granulocytic differentiation by RA or DMSO. In K562 cells, HTIF1α RNA levels did not change after hemin-induced erythroid differentiation. These results suggest that HTIF1α could play a role in myeloid differentiation, being distinctly regulated in hematopoietic lineages. [ABSTRACT FROM AUTHOR]