Maternal uniparental disomy for chromosome 14 [upd(14)mat] is associated with a characteristic phenotype including pre‐ and postnatal growth retardation, muscular hypotonia, feeding problems, motor delay, small hands and feet, precocious puberty and truncal obesity. Patients with upd(14)mat show features overlapping with Prader–Willi syndrome (PWS) and are probably underdiagnosed. Maternal upd(14) is frequently described in carriers of a Robertsonian translocation involving chromosome 14, but is also found in patients with a normal karyotype. Based on the above mentioned criteria we have identified six patients with upd(14)mat including two patients with a normal karyotype, one patient with a de novo Robertsonian translocation (14;21), one patient with a familial Robertsonian translocation (13;14) and two patients with a marker chromosome. In addition, we analyzed a cohort of 33 patients with low birth weight, feeding difficulties and consecutive obesity in whom PWS had been excluded by methylation analysis of SNRPN. In four of these patients (12%) we detected upd(14)mat. For rapid testing of upd(14)mat we analyzed the methylation status of the imprinted MEG3 locus. In conclusion, we recommend considering upd(14)mat in patients with low birth weight, growth retardation, neonatal feeding problems, muscular hypotonia, motor delay, precocious puberty and truncal obesity as well as in patients with a PWS like phenotype presenting with low birth weight, feeding difficulties and obesity. © 2006 Wiley‐Liss, Inc.
Infertility – the inability to achieve conception or sustain a pregnancy through to live birth – is very common and affects about 15% of couples. While chromosomal or genetic abnormalities associated with azoospermia, severe oligozoospermia or primary ovarian failure were of no importance for reproduction prior to the era of in vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI), advances in assisted reproductive techniques (ART) now enable many infertile couples to have children. These developments have raised the question of the genetic consequences of ICSI: concerns of the potential harm of the invasive procedure and concerns about the genetic risk. The infertile male and female definitely have an increased risk to carry a chromosomal abnormality. Detection of such an abnormality is of fundamental importance for the diagnosis of infertility, the following treatment, the evaluation of the risk for the future child and the appropriate management of the pregnancy to be obtained. Therefore, cytogenetic screening of both partners is mandatory prior to any type of ART. The present review is based on several surveys on male and female infertility and analyzes the types and frequencies of the different reported chromosome abnormalities according to the type of impairment of spermatogenesis and the type of treatment planned or performed. With regard to assisted reproductive techniques (especially ICSI) the main types of chromosomal abnormalities are discussed and their potential risks for ICSI. If available, reported cases of performed ICSI and its outcome are presented. The detection of an abnormal karyotype should lead to comprehensive genetic counselling, which should include all well-known information about the individual type of anomaly, its clinical relevance, its possible inheritance, the genetic risk of unbalanced offspring, and the possibilities of prenatal diagnosis. Only this proceeding allows at-risk couples to make an informed decision regarding whether or not to proceed with ART. These decisions can be made only when both partners have clearly understood the genetic risks and possible consequences when ART is used.
Among full autosomal trisomies, only trisomies of chromosome 21 (Down syndrome), 18 (Edwards syndrome) and 13 (Patau syndrome) are compatible with postnatal survival. But the mechanisms, how a supernumerary chromosome disrupts the normal development and causes specific phenotypes, are still not fully explained. As an alternative to gene dosage effect due to the trisomic chromosome a genome-wide transcriptional dysregulation has been postulated. The aim of this study was to define the transcriptional changes in trisomy 13, 18, and 21 during early fetal development in order to obtain more insights into the molecular etiopathology of aneuploidy. Using oligonucleotide microarrays, we analyzed whole genome expression profiles in cultured amniocytes (AC) and chorionic villus cells (CV) from pregnancies with a normal karyotype and with trisomies of human chromosomes 13, 18 and 21. We observed a low to moderate up-regulation for a subset of genes of the trisomic chromosomes. Transcriptional levels of most of the genes on the supernumerary chromosome appeared similar to the respective chromosomal pair in normal karyotypes. A subset of chromosome 21 genes including the DSCR1 gene involved in fetal heart development was consistently up-regulated in different prenatal tissues (AC, CV) of trisomy 21 fetuses whereas only minor changes were found for genes of all other chromosomes. In contrast, in trisomy 18 vigorous downstream transcriptional changes were found. Global transcriptome analysis for autosomal trisomies 13, 18, and 21 supported a combination of the two major hypotheses.
Background: Logbooks are widely used to set learning outcomes and to structure and standardize teaching in clinical settings. Experience shows that logbooks are not always optimally employed in clinical training. In this article, we have summarized our own experiences as well as results of studies into twelve tips on how to successfully implement logbooks into clinical settings. Methods: We conducted both a workshop concerning the importance of logbook training to exchange experiences in teaching practice, organization, didactic knowledge and a literature research to compare our own experiences and add additional aspects. Results: Tips include the process of developing the logbook itself, the change-management process, conditions of training and the integration of logbooks into the curriculum. Conclusions: Logbooks can be a valuable tool for training in clinical settings, especially when multiple sites are involved, when you take our tips into consideration.
To date, uniparental disomy (UPD) with phenotypic relevance is described for different chromosomes and it is likely that additional as yet unidentified UPD phenotypes exist. Due to technical difficulties and limitations of time and resources, molecular analyses for UPD using microsatellite markers are only performed in cases with specific phenotypic features. In this study, we carried out a whole genome UPD screening based on a microarray genotyping technique. Six patients with the diagnosis of both complete or segmental UPD including Prader-Willi syndrome (PWS; matUPD15), Angelman syndrome (AS; patUPD15), Silver-Russell syndrome (SRS; matUPD7), Beckwith-Wiedemann syndrome (BWS; patUPD11p), pseudohypoparathyroidism (PHP; patUPD20q) and a rare chromosomal rearrangement (patUPD2p, matUPD2q), were genotyped using the GeneChip Human Mapping 10K Array. Our results demonstrate the presence of UPD in the patients with high efficiency and reveal clues about the mechanisms of UPD formation. We thus conclude that array based SNP genotyping is a fast, cost-effective, and reliable approach for whole genome UPD screening.
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