title: Mutational spectrum of CENP-B box and α-satellite DNA on chromosome 21 in Down syndrome children.
abstract: The centromere is responsible for the correct inheritance of eukaryotic chromosomes during cell division. Centromere protein B (CENP‑B) and its 17 base pair binding site (CENP‑B box), which appears at regular intervals in centromeric α-satellite DNA (α-satDNA), are important for the assembly of the centromere components. Therefore, it is conceivable that CENP-B box mutations may induce errors in cell division. However, the association between the deoxynucleotide alterations of the CENP‑B box and the extra chromosome 21 (Chr21) present in patients with Down syndrome (DS) remains to be elucidated. The mutational spectrum of the α‑satDNA, including 4 functional CENP‑B boxes in Chr21 from 127 DS and 100 healthy children were analyzed by direct sequencing. The de novo occurrences of mutations within CENP‑B boxes in patients with DS were excluded. The prevalence of 6 novel mutations (g.661delC, g.1035_1036insA, g.1076_1077insC, g.670T>G, g.1239A>T, g.1343T>C) and 3 single nucleotide polymorphisms (g.727C/T, g.863A/C, g.1264C/G) were not significantly different between DS and controls (P>0.05). However, g.525C/G (P=0.01), g.601T/C (P=0.00000002), g.1279A/G (P=0.002), g.1294C/T (P=0.0006) and g.1302 G/T (P=0.004) were significantly associated with the prevalence of DS (P<0.05). The results indicated that CENP‑B boxes are highly conserved in DS patients and may not be responsible for Chr21 nondisjunction events. However, α‑satDNA in Chr21 is variable and deoxynucleotide deletions, mutations and polymorphisms may act as potential molecular diagnostic markers of DS.
authors.affiliation: Department of Obstetrics and Gynecology, The First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, P.R. China.
authors.forename: Qian
authors.initials: Q
authors.lastname: Chen
authors.affiliation: Pediatrics Research Institute, Children's Hospital of Chongqing Medical University, Ministry of Education Key Laboratory of Child Development and Disorders, Chongqing 400014, P.R. China.
authors.forename: Bin
authors.initials: B
authors.lastname: Tan
authors.affiliation: Laboratory of Reproductive Biology, Public Health College, Chongqing Medical University, Chongqing 400016, P.R. China.
authors.forename: Jun-Lin
authors.initials: JL
authors.lastname: He
authors.affiliation: Laboratory of Reproductive Biology, Public Health College, Chongqing Medical University, Chongqing 400016, P.R. China.
authors.forename: Xue-Qing
authors.initials: XQ
authors.lastname: Liu
authors.affiliation: Laboratory of Reproductive Biology, Public Health College, Chongqing Medical University, Chongqing 400016, P.R. China.
authors.forename: Xue-Mei
authors.initials: XM
authors.lastname: Chen
authors.affiliation: Laboratory of Reproductive Biology, Public Health College, Chongqing Medical University, Chongqing 400016, P.R. China.
authors.forename: Ru-Fei
authors.initials: RF
authors.lastname: Gao
authors.affiliation: Pediatrics Research Institute, Children's Hospital of Chongqing Medical University, Ministry of Education Key Laboratory of Child Development and Disorders, Chongqing 400014, P.R. China.
authors.forename: Jing
authors.initials: J
authors.lastname: Zhu
authors.affiliation: Laboratory of Reproductive Biology, Public Health College, Chongqing Medical University, Chongqing 400016, P.R. China.
authors.forename: Ying-Xiong
authors.initials: YX
authors.lastname: Wang
authors.affiliation: Department of Obstetrics and Gynecology, The First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, P.R. China.
authors.forename: Hong-Bo
authors.initials: HB
authors.lastname: Qi
mesh_terms: D001483:Base Sequence; D051936:Centromere Protein B / Q000235:genetics*; D002648:Child; D002681:China / Q000453:epidemiology; D002891:Chromosomes, Human, Pair 21 / Q000235:genetics*; D004252:DNA Mutational Analysis; D004276:DNA, Satellite / Q000235:genetics*; D004314:Down Syndrome / Q000453:epidemiology / Q000235:genetics*; D006801:Humans; D009154:Mutation; D011110:Polymorphism, Genetic
chemical_list: D051936:Centromere Protein B; D004276:DNA, Satellite