Maximal γ-globin expression in the compound heterozygous state for –175 ^Gγ HPFH and β⁰39 nonsense thalassaemia: a case study

The –175 (T→C) Gγ hereditary persistence of fetal haemoglobin is a very rare promoter mutation occurring in Caucasians as well as in African-Americans. Heterozygotes for this non-deletional HPFH show 20% HbF, mostly of Gγ type. We describe here a healthy Sardinian man who coinherited –175 (T→C) Gγ HPFH with the β-thalassaemia codon 39 nonsense mutation in trans; he showed 64% HbF, 100% of Gγ type. Although the β-globin haplotype pattern (II/II) was indicative of the presence of the AγT allele on both chromosomes, the AγT expression was undetectable by HPLC even in red cell populations separated by age. The proband was, moreover, homozygous for the –4 bp deletion at position -225 to -222 of Aγ promoter which has recently been associated with decreased AγT globin expression. These findings suggest that this maximal overexpression of Gγ-globin probably reflects intensified stimulation of the mutated Gγ promoter in this hitherto undescribed genetic condition

Fetal hemoglobin expression in compound heterozygotes for -117 (G→A) ^Aγ HPFH and β⁰39 nonsense thalassemia

The-117(G→A) Aγ hereditary persistence of fetal hemoglobin (Greek HPFH) and β039-thal mutations are rather frequent in Sardinia so that their interaction is to be expected. Characterization of eight compound heterozygotes for these defects indicated that HPFH was linked to haplotype VII and β039-thal to haplotype II. Haplotype II β039-thal chromosome carries the AγT gene which is a useful marker of γ-gene expression. Since the Hb F level in these compound heterozygotes was significantly higher than in 46 -117 HPFH carriers, the Aγt, and Gγ globin level was determined. AγT was underexpressed while Gγ was significantly increased, which suggests that in -117 Aγ HPFH/β039-thal healthy subjects the increase in Hb F production is determined only by the -117 mutated Aγ gene and the adjacent Gγ gene

Genome-wide association analyses identify 18 new loci associated with serum urate concentrations

<p>Elevated serum urate concentrations can cause gout, a prevalent and painful inflammatory arthritis. By combining data from >140,000 individuals of European ancestry within the Global Urate Genetics Consortium (GUGC), we identified and replicated 28 genome-wide significant loci in association with serum urate concentrations (18 new regions in or near TRIM46, INHBB, SEMBT1, TMEM171, VEGFA, BAZ1B, PRKAG2, STC1, HNF4G, A1CF, ATXN2, UBE2Q2, IGF1R, NFAT5, MAF, HLF, ACVR1B-ACVRL1 and B3GNT4). Associations for many of the loci were of similar magnitude in individuals of non-European ancestry. We further characterized these loci for associations with gout, transcript expression and the fractional excretion of urate. Network analyses implicate the inhibins-activins signaling pathways and glucose metabolism in systemic urate control. New candidate genes for serum urate concentration highlight the importance of metabolic control of urate production and excretion, which may have implications for the treatment and prevention of gout.</p>