0000000000343391
AUTHOR
Bärbel Grossmann
Genomic structure and paralogous regions of the inversion breakpoint occurring between human chromosome 3p12.3 and orangutan chromosome 2.
Intrachromosomal duplications play a significant role in human genome pathology and evolution. To better understand the molecular basis of evolutionary chromosome rearrangements, we performed molecular cytogenetic and sequence analyses of the breakpoint region that distinguishes human chromosome 3p12.3 and orangutan chromosome 2. FISH with region-specific BAC clones demonstrated that the breakpoint-flanking sequences are duplicated intrachromosomally on orangutan 2 and human 3q21 as well as at many pericentromeric and subtelomeric sites throughout the genomes. Breakage and rearrangement of the human 3p12.3-homologous region in the orangutan lineage were associated with a partial loss of dup…
Isolation and differential expression of two isoforms of the ROBO2/Robo2 axon guidance receptor gene in humans and mice.
AbstractExpression of Robo receptor molecules is important for axon guidance across the midline of the mammalian central nervous system. Here we describe novel isoform a of human ROBO2, which is initially strongly expressed in the fetal human brain but thereafter only weakly expressed in adult brain and a few other tissues. The known isoform b of ROBO2 shows a more or less ubiquitous expression pattern, suggesting diverse functional roles. The genomic structure and distinct expression patterns of Robo2a and Robo2b have been conserved in the mouse, but in contrast to human ROBO2a mouse Robo2a is also abundant in adult brain. Exons 1 and 2 of human ROBO2a lie in an inherently unstable DNA seg…
Disruption of TCBA1 associated with a de novo t(1;6)(q32.2;q22.3) presenting in a child with developmental delay and recurrent infections
A boy with developmental delay, particularly of speech, a distinct face, antineutrophil cytoplasmic antibodies, and recurrent infections was found to have an apparently balanced de novo t(1;6)(q32.3;q22.3) translocation. Fluorescent in situ hybridisation with BAC/PAC clones and long range polymerase chain reaction products assessed in the human genome sequence localised the chromosome 1 breakpoint to a 9.8 kb segment within a hypothetical gene, LOC388735, and the chromosome 6 breakpoint to a 12.8 kb segment in intron 4 of the T-cell lymphoma breakpoint-associated target 1 (TCBA1) gene. Disruption and/or formation of TCBA1 fusion genes in T cell lymphoma and leukaemia cell lines suggests a r…
A high oocyte yield for intracytoplasmic sperm injection treatment is associated with an increased chromosome error rate.
Objective To compare the chromosome error rate among oocytes from stimulated ovaries after retrieval of 1–5 oocytes, 6–10 oocytes, and >10 oocytes. Design Retrospective cohort study. Setting A university-based human genetic institute in collaboration with a private fertility center. Patient(s) Nine hundred thirty-three women undergoing intracytoplasmic sperm injection (ICSI) with a poor prognosis. Intervention(s) Oocyte collection with ovarian stimulation. Polar body testing of ICSI oocytes for common chromosome errors. Main Outcome Measure(s) Chromosome error rate in oocytes, as determined by five-color fluorescence in situ hybridization. Result(s) In women less than 35 years and women bet…
Comparative cytogenetics of human chromosome 3q21.3 reveals a hot spot for ectopic recombination in hominoid evolution
Fluorescence in situ hybridization mapping of fully integrated human BAC clones to primate chromosomes, combined with precise breakpoint localization by PCR analysis of flow-sorted chromosomes, was used to analyze the evolutionary rearrangements of the human 3q21.3-syntenic region in orangutan, siamang gibbon, and silvered-leaf monkey. Three independent evolutionary breakpoints were localized within a 230-kb segment contained in BACs RP11-93K22 and RP11-77P16. Approximately 200 kb of the human 3q21.3 sequence was not present on the homologous orangutan, siamang, and Old World monkey chromosomes, suggesting a genomic DNA insertion into the breakpoint region in the lineage leading to humans a…
Homozygous disruption of PDZD7 by reciprocal translocation in a consanguineous family: a new member of the Usher syndrome protein interactome causing congenital hearing impairment.
A homozygous reciprocal translocation, 46,XY,t(10;11),t(10;11), was detected in a boy with non-syndromic congenital sensorineural hearing impairment. Both parents and their four other children were heterozygous translocation carriers, 46,XX,t(10;11) and 46,XY,t(10;11), respectively. Fluorescence in situ hybridization of region-specific clones to patient chromosomes was used to localize the breakpoints within bacterial artificial chromosome (BAC) RP11-108L7 on chromosome 10q24.3 and within BAC CTD-2527F12 on chromosome 11q23.3. Junction fragments were cloned by vector ligation and sequenced. The chromosome 10 breakpoint was identified within the PDZ domain containing 7 (PDZD7) gene, disrupti…
Plasticity of human chromosome 3 during primate evolution.
Comparative mapping of more than 100 region-specific clones from human chromosome 3 in Bornean and Sumatran orangutans, siamang gibbon, and Old and New World monkeys allowed us to reconstruct ancestral simian and hominoid chromosomes. A single paracentric inversion derives chromosome 1 of the Old World monkey Presbytis cristata from the simian ancestor. In the New World monkey Callithrix geoffroyi and siamang, the ancestor diverged on multiple chromosomes, through utilizing different breakpoints. One shared and two independent inversions derive Bornean orangutan 2 and human 3, implying that neither Bornean orangutans nor humans have conserved the ancestral chromosome form. The inversions, f…
Segmental duplication associated with evolutionary instability of human chromosome 3p25.1
Fluorescence in situ hybridization (FISH) of human bacterial artificial chromosome (BAC) clones to orangutan metaphase spreads localized a breakpoint between human chromosome 3p25.1 and orangutan chromosome 2 to a <30-kb interval. The inversion occurred in a relatively gene-rich region with seven genes within 500 kb. The underlying breakpoint is closely juxtaposed to validated genes, however no functional gene has been disrupted by the evolutionary rearrangement. An approximately 21-kb DNA segment at the 3p25.1 breakpoint region has been duplicated intrachromosomally and interchromosomally to multiple regions in the orangutan and human genomes, providing additional evidence for the role …
De novo t(12;17)(p13.3;q21.3) translocation with a breakpoint near the 5' end of the HOXB gene cluster in a patient with developmental delay and skeletal malformations.
A boy with severe mental retardation, funnel chest, bell-shaped thorax, and hexadactyly of both feet was found to have a balanced de novo t(12;17)(p13.3;q21.3) translocation. FISH with BAC clones and long-range PCR products assessed in the human genome sequence localized the breakpoint on chromosome 17q21.3 to a 21-kb segment that lies <30 kb upstream of the HOXB gene cluster and immediately adjacent to the 3′ end of the TTLL6 gene. The breakpoint on chromosome 12 occurred within telomeric hexamer repeats and, therefore, is not likely to affect gene function directly. We propose that juxtaposition of the HOXB cluster to a repetitive DNA domain and/or separation from required cis-regulatory …
Outcome of intracytoplasmic sperm injection with and without polar body diagnosis of oocytes.
Objective To compare the reproductive outcome of women undergoing intracytoplasmic sperm injection (ICSI) with or without polar body diagnosis of oocytes. Design Nonrandomized retrospective study. Setting University-based human genetic institute in collaboration with a private fertility center. Patient(s) Six hundred seven women undergoing ICSI with polar body diagnosis and 591 women undergoing ICSI without polar body diagnosis at the same time in the same fertility center. Intervention(s) Polar body testing of ICSI oocytes by five-color fluorescence in situ hybridization. Main Outcome Measure(s) Pregnancy rate (positive fetal heartbeats) and live-birth rate (of at least one child). Result(…