caa a22 4500 46798476X CHVBK 20180323112528.0 cr unu---uuuuu 170328e19901001xx s 000 0 eng 10.1007/BF00193580 doi (NATIONALLICENCE)springer-10.1007/BF00193580 X chromosome imprinting in fragile×syndrome [Elektronische Daten] [Wei-Dong Yu, Sharon Wenger, Mark Steele] Summary: Laird et al. (1987) hypothesized that there are at least four cis-acting alleles or ‘chromosome states' at Xq27 that increasingly delay replication at this chromosomal area resulting in its increasing fragility in vitro. When on the inactive×chromosome, the proposed third (‘mutated') allele can permanently block reactivation of its cis Xq27 area as the chromosome passes through female meiosis. Males and some females who inherit such an ‘imprinted' fragile×chromosome (the fourth proposed allele) will be clinically affected due to impaired transcription of genes in the ‘imprinted' Xq27 area. To test this hypothesis, late replication reverse banding patterns at Xq27 were evaluated in cultured lymphoblastoid cell lines from 25 subjects. Our data suggest that DNA replication of the presumed ‘imprinted' Xq27 region in affected fragile×patients is indeed later relative to Xq27 on the active×chromosome in other subjects. These results support in part Laird's hypothesis of chromosomal imprinting in fragile×syndrome. Springer-Verlag, 1990 Yu Wei-Dong Department of Pediatrics, School of Medicine, University of Pittsburgh, 15213-2583, Pittsburgh, PA, USA aut Wenger Sharon Department of Pediatrics, School of Medicine, University of Pittsburgh, 15213-2583, Pittsburgh, PA, USA aut Steele Mark Department of Pediatrics, School of Medicine, University of Pittsburgh, 15213-2583, Pittsburgh, PA, USA aut Human Genetics Springer-Verlag 85/6(1990-10-01), 590-594 0340-6717 85:6<590 1990 85 439 https://doi.org/10.1007/BF00193580 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF00193580 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Yu Wei-Dong Department of Pediatrics, School of Medicine, University of Pittsburgh, 15213-2583, Pittsburgh, PA, USA aut NATIONALLICENCE 700 1- Wenger Sharon Department of Pediatrics, School of Medicine, University of Pittsburgh, 15213-2583, Pittsburgh, PA, USA aut NATIONALLICENCE 700 1- Steele Mark Department of Pediatrics, School of Medicine, University of Pittsburgh, 15213-2583, Pittsburgh, PA, USA aut NATIONALLICENCE 773 0- Human Genetics Springer-Verlag 85/6(1990-10-01), 590-594 0340-6717 85:6<590 1990 85 439 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer