@article {10515, title = {A complete duplication of X chromosome resulting in a tricentric isochromosome originated by centromere repositioning.}, journal = {Mol Cytogenet}, volume = {10}, year = {2017}, month = {2017}, pages = {22}, abstract = {

BACKGROUND: Neocentromeres are rare and considered chromosomal aberrations, because a non-centromeric region evolves in an active centromere by mutation. The literature reported several structural anomalies of X chromosome and they influence the female reproductive capacity or are associated to Turner syndrome in the presence of monosomy X cell line.

CASE PRESENTATION: We report a case of chromosome X complex rearrangement found in a prenatal diagnosis. The fetal karyotype showed a mosaicism with a 45,X cell line and a 46 chromosomes second line with a big marker, instead of a sex chromosome. The marker morphology and fluorescence in situ hybridization (FISH) characterization allowed us to identify a tricentric X chromosome constituted by two complete X chromosome fused at the p arms telomere and an active neocentromere in the middle, at the union of the two Xp arms, where usually are the telomeric regions. FISH also showed the presence of a paracentric inversion of both Xp arms. Furthermore, fragility figures were found in 56\% of metaphases from peripheral blood lymphocytes culture at birth: a shorter marker chromosome and an apparently acentric fragment frequently lost.

CONCLUSIONS: At our knowledge, this is the first isochromosome of an entire non-acrocentric chromosome. The neocentromere is constituted by canonical sequences but localized in an unusual position and the original centromeres are inactivated. We speculated that marker chromosome was the result of a double rearrangement: firstly, a paracentric inversion which involved the Xp arm, shifting a part of the centromere at the p end and subsequently a duplication of the entire X chromosome, which gave rise to an isochromosome. It is possible to suppose that the first event could be a result of a non-allelic homologous recombination mediated by inverted low-copy repeats. As expected, our case shows a Turner phenotype with mild facial features and no major skeletal deformity, normal psychomotor development and a spontaneous development of puberty and menarche, although with irregular menses since the last follow-up.

}, issn = {1755-8166}, doi = {10.1186/s13039-017-0323-7}, author = {Villa, N and Conconi, D and Benussi, D Gambel and Tornese, G and Crosti, F and Sala, E and Dalpr{\`a}, L and Pecile, V} } @article {10564, title = {Impaired fasting glucose and impaired glucose tolerance in children and adolescents with overweight/obesity.}, journal = {J Endocrinol Invest}, volume = {40}, year = {2017}, month = {2017 Apr}, pages = {409-416}, abstract = {

OBJECTIVE: To investigate in a large sample of overweight/obese (OW/OB) children and adolescents the prevalence of prediabetic phenotypes such as impaired fasting glucose (IFG) and impaired glucose tolerance (IGT), and to assess their association with cardiometabolic risk (CMR) factors including hepatic steatosis (HS).

METHODS: Population data were obtained from the CARdiometabolic risk factors in children and adolescents in ITALY study. Between 2003 and 2013, 3088 youths (972 children and 2116 adolescents) received oral glucose tolerance test (OGTT) and were included in the study. In 798 individuals, abdominal ultrasound for identification of HS was available.

RESULTS: The prevalence of IFG (3.2 vs. 3.3\%) and IGT (4.6 vs. 5.0\%) was similar between children and adolescents. Children with isolated IGT had a 2-11 fold increased risk of high LDL-C, non-HDL-C, Tg/HDL-C ratio, and low insulin sensitivity, when compared to those with normal glucose tolerance (NGT). No significant association of IFG with any CMR factor was found in children. Among adolescents, IGT subjects, and to a lesser extent those with IFG, showed a worse CMR profile compared to NGT subgroup. In the overall sample, IGT phenotype showed a twofold increased risk of HS compared to NGT subgroup.

CONCLUSIONS: Our study shows an unexpected similar prevalence of IFG and IGT between children and adolescents with overweight/obesity. The IGT phenotype was associated with a worse CMR profile in both children and adolescents. Phenotyping prediabetes conditions by OGTT should be done as part of prediction and prevention of cardiometabolic diseases in OW/OB youth since early childhood.

}, keywords = {Adolescent, Blood Glucose, Case-Control Studies, Child, Fasting, Female, Glucose Intolerance, Glucose Tolerance Test, Humans, Insulin, Insulin Resistance, Italy, Male, Obesity, Overweight, Prediabetic State, Prevalence}, issn = {1720-8386}, doi = {10.1007/s40618-016-0576-8}, author = {Di Bonito, P and Pacifico, L and Chiesa, C and Valerio, G and Miraglia Del Giudice, E and Maffeis, C and Morandi, A and Invitti, C and Licenziati, M R and Loche, S and Tornese, G and Franco, F and Manco, M and Baroni, M G} }