Yunis-Varón syndrome (YVS) is an autosomal-recessive disorder with cleidocranial dysplasia, digital anomalies, and severe neurological involvement. Enlarged vacuoles are found in neurons, muscle, and cartilage. By whole-exome sequencing, we identified frameshift and missense mutations of FIG4 in affected individuals from three unrelated families. FIG4 encodes a phosphoinositide phosphatase required for regulation of PI(3,5)P(2) levels, and thus endosomal trafficking and autophagy. In a functional assay, both missense substitutions failed to correct the vacuolar phenotype of Fig4-null mouse fibroblasts. Homozygous Fig4-null mice exhibit features of YVS, including neurodegeneration and enlarged vacuoles in neurons. We demonstrate that Fig4-null mice also have small skeletons with reduced trabecular bone volume and cortical thickness and that cultured osteoblasts accumulate large vacuoles. Our findings demonstrate that homozygosity or compound heterozygosity for null mutations of FIG4 is responsible for YVS, the most severe known human phenotype caused by defective phosphoinositide metabolism. In contrast, in Charcot-Marie-Tooth disease type 4J (also caused by FIG4 mutations), one of the FIG4 alleles is hypomorphic and disease is limited to the peripheral nervous system. This genotype-phenotype correlation demonstrates that absence of FIG4 activity leads to central nervous system dysfunction and extensive skeletal anomalies. Our results describe a role for PI(3,5)P(2) signaling in skeletal development and maintenance.
Pathogenic factors suggest that different forms of vascular injury to the fetal brain (emboli, haemorrhage, vasoconstriction, disseminated intravascular coagulation) can produce partial brain destruction, diminished intracranial pression and skull collapse in the fetal brain disruption sequence.
Mexico is recognized as a country with a high prevalence of gastroschisis, although the cause of this remains unclear. We define the prevalence and potential risk factors for gastroschisis in a public hospital from west México. A casecontrol study was conducted among 270 newborns, including 90 patients with nonsyndromic gastroschisis (cases) and 180 infants without birth defects (controls), born all during the period 2009 to 2013 at the Hospital Civil de Guadalajara "Dr. Juan I. Menchaca" (Guadalajara, Mexico), from a total of 51 145 live births. Potential maternal risk factors for gastroschisis were compared using multivariate logistic regression analysis to evaluate the deviance explained by different variables of interest. The overall prevalence of gastroschisis in live births was 17.6 per 10 000 births (95% confidence interval [CI] 14.0-21.2), whereas in offspring of women ≤19 years old was 29.9 per 10 000 births (95% CI 21.9-38.0). Mothers ≤19 years (adjusted odds ratio [aOR] 2.8: 95% CI 1.5-5.1), anemia during pregnancy (aOR 10.7; 95% CI 2.0-56.9), first-trimester exposure to hormonal contraceptives (aOR 3.7; 95% CI 1.0-13.0), and first-trimester alcohol consumption (aOR 3.4; 95% CI 1.6-7.3), were associated with gastroschisis. Contrarily, adjusted OR for pre-pregnancy body mass index ≥25 kg/m 2 has protective odds (aOR 0.2; 95% CI 0.1-0.5). Our results suggest an increased risk for gastroschisis among mothers under the age of 20, with anemia during pregnancy, and those who used hormonal contraceptives or consumed alcohol during early pregnancy, whereas, pre-pregnancy overweight has a protective OR, and they are discussed as clues in its pathogenesis.
Dietary polyphenolics, such as curcumin, have shown antioxidant and anti-inflammatory effects. Some antioxidants cause DNA strand breaks in excess of transition metal ions, such as copper. The aim of this study was to evaluate the in vitro effect of curcumin in the presence of increasing concentrations of copper to induce DNA damage in murine leukocytes by the comet assay. Balb-C mouse lymphocytes were exposed to 50 microM curcumin and various concentrations of copper (10 microM, 100 microM and 200 microM). Cellular DNA damage was detected by means of the alkaline comet assay. Our results show that 50 microM curcumin in the presence of 100-200 microM copper induced DNA damage in murine lymphocytes. Curcumin did not inhibit the oxidative DNA damage caused by 50 microM H2O2 in mouse lymphocytes. Moreover, 50 microM curcumin alone was capable of inducing DNA strand breaks under the tested conditions. The increased DNA damage by 50 mM curcumin was observed in the presence of various concentrations of copper, as detected by the alkaline comet assay.
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