1. Ciccoli L, De Felice C, Paccagnini E, Leoncini S, Pecorelli A, Signorini C, Belmonte G, Valacchi G, Rossi M, Hayek J. {{Morphological changes and oxidative damage in Rett Syndrome erythrocytes}}. {Biochim Biophys Acta};2011 (Dec 13)
BACKGROUND: Hypoxemia and increased oxidative stress (OS) have been reported in Rett Syndrome (RTT), a genetical neurodevelopmental disorder. Although OS and hypoxemia can lead to red blood cells (RBCs) shape abnormalities, no information on RBCs morphology in RTT exists. Here, RBCs shape was evaluated in RTT patients and healthy subjects as a function of OS markers, blood oxygenation, pulmonary gas exchange, and cardio-respiratory parameters. METHODS: RBCs morphology was evaluated by Scanning Electron Microscopy. Intraerythrocyte and plasma non protein-bound iron (NPBI), esterified F(2)-Isoprostanes, 4-HNE protein adducts (4-HNE PAs) were measured. Pulmonary oxygen gradients and PaO(2) were evaluated by gas analyzers and cardiopulmonary variables by pulse oximetry. In RTT patients these parameters were assessed before and after omega-3 polyunsaturated fatty acids (omega-3 PUFAs) administration. RESULTS: Altered RBCs shapes (leptocytes) and increased NPBI were present in RTT, together with increased erythrocyte membrane esterified F(2)-IsoPs and 4-HNE PAs. Abnormal erythrocyte shapes were related to OS markers levels, pulmonary gas exchange, PaO(2) and cardio-respiratory variables. After omega-3 PUFAs, a decrease of leptocytes was accompanied by a progressive increase in reversible forms of RBCs. This partial RBCs morphology rescue was related to decreased OS damage markers, improved pulmonary oxygen exchange, and cardiopulmonary physiology. CONCLUSIONS: These findings indicate that in RTT 1) RBCs shape is altered; 2) the OS-hypoxia diad is critical in generating altered RBCs shape and membrane damage; 3) omega-3 PUFAs are able to partially rescue RBCs morphology and the OS-derived damage. GENERAL SIGNIFICANCE: RBCs morphology is an important biosensor for OS imbalance and chronic hypoxemia.
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2. Zhang J, Bao X, Cao G, Jiang S, Zhu X, Lu H, Jia L, Pan H, Fehr S, Davis M, Leonard H, Ravine D, Wu X. {{What does the nature of the MECP2 mutation tell us about parental origin and recurrence risk in Rett syndrome?}}. {Clin Genet};2011 (Dec 19)
The MECP2 mutations occurring in the severe neurological disorder Rett syndrome are predominantly de novo, with familial cases rare. The aims of this study were to provide a precise estimate of the parental origin of MECP2 mutations using a large Chinese sample and to assess whether parental origin varied by mutation type. The parental origin was paternal in 84/88 (95.5%, (95% CI 88.77-98.75)) of sporadic Chinese cases. However in a pooled sample including data from the literature the spectrum of mutations occurring on maternally and paternally derived chromosomes differed significantly. The excess we found of ‘single base pair gains or losses’ on maternally derived MECP2 gene alleles suggests that this mutational category is associated with an elevated risk of gonadal mosaicism, which has implications for genetic counseling.
