Report of a new mutation in CYBB gene in two patients with X linked chronic granulomatous disease

Background: The X-linked form of chronic granulomatous disease (CGD) is a primary immunodeficiency that affects phagocytes of the innate immune system and is characterized by an increased susceptibility to severe bacterial and fungal infections. It is caused by mutations in the CYBB gene, which encodes the 91-kD subunit of phagocyte NADPH oxidase. Aim: To identify the mutation in the CYBB gene in two unrelated patients from Chile with, the diagnosis of X-linked CGD and their families. Patients and methods: The molecular genetic defects of two unrelated patients from Chile with X-linked CGD caused by defects in the CYBB gene were investigated. The underlying mutation was investigated by single strand conformation polymorphism (SSCP) analysis of PCR-amplified genomic DNA and by sequencing of the affected gene region. Results: We found an insertion c.1267_1268insA in exon 10 leading to a frameshift mutation. This mutation is a novel report. We also identified a splice site mutation in the other patient, that presented a c.1326 +1 G > A substitution in intron 10. The mutation was also detectable in his heterozygous mother. Conclusions: This is the first report of the clinical and molecular characterization of Chilean patients with mutations in CYBB gene (Rev Med Chile 2006; 134: 965-72).134896597

Mitochondrial phylogeography and demographic history of the Vicuña: implications for conservation

The vicuña (Vicugna vicugna; Miller, 1924) is a conservation success story, having recovered from near extinction in the 1960s to current population levels estimated at 275 000. However, lack of information about its demographic history and genetic diversity has limited both our understanding of its recovery and the development of science-based conservation measures. To examine the evolution and recent demographic history of the vicuña across its current range and to assess its genetic variation and population structure, we sequenced mitochondrial DNA from the control region (CR) for 261 individuals from 29 populations across Peru, Chile and Argentina. Our results suggest that populations currently designated as Vicugna vicugna vicugna and Vicugna vicugna mensalis comprise separate mitochondrial lineages. The current population distribution appears to be the result of a recent demographic expansion associated with the last major glacial event of the Pleistocene in the northern (18 to 22°S) dry Andes 14–12 000 years ago and the establishment of an extremely arid belt known as the 'Dry Diagonal' to 29°S. Within the Dry Diagonal, small populations of V. v. vicugna appear to have survived showing the genetic signature of demographic isolation, whereas to the north V. v. mensalis populations underwent a rapid demographic expansion before recent anthropogenic impacts