UK families with children with rare chromosome disorders: Changing experiences of diagnosis and counselling (2003-2013).

The latest United Kingdom (UK) strategy for rare diseases emphasises the need to empower affected populations to improve diagnosis, intervention, and coordination of care. Families who have a child with a rare chromosome disorder (RCD) are a challenging group to include. We report the findings of 2 large-scale surveys, undertaken by the UK RCD Support Group Unique, of these families' experiences over a 10-year period. Seven stages of the patient journey were examined. From pre-testing, through diagnosis, genetics consultation, clinical follow-up and peer support. Overall, 1158 families replied; 36.4% response rate (2003) and 53.6% (2013). Analysis of responses identifies significant differences (P < .001) over time with a decrease in results reported face to face (76%-62%), doubling by telephone (12%-22%), improved explanation of chromosome disorder (57%-75%), and increased signposting to peer support group (34%-62%). However, conduct of the consultation raises a number of important questions. Overall, 28 aspects of the patient journey are recognised as requiring improvement; only 12/28 are currently incorporated in UK service specifications. Involvement of RCD families has identified key service improvements. This approach can empower those affected by such extremely rare disorders, and also enable professionals to design improved services in partnership with "expert families." Further surveys are planned.

Self-assessed remission rates after electroconvulsive therapy of depressive disorders.

BACKGROUND: Electroconvulsive therapy (ECT) effectively treats severe depression, but not all patients remit. The aim of the study was to identify clinical factors that associate with ECT-induced remission in a community setting. METHODS: Depressed patients who underwent ECT in 2011-2014 were identified from the Swedish National Quality Register for ECT. Remission was defined as self-rated Montgomery-Åsberg Depression Rating Scale scores of 0-10 after ECT. Other registers provided data on previous antidepressant use, comorbidities, and demographics. RESULTS: Of 1671 patients fulfilling the inclusion criteria, 42.8% achieved remission. Older age, education length over 9 years, psychotic symptoms, shorter duration of preceding antidepressant use, pulse width stimulus≥0.50ms, absence of substance use disorders, anxiety diagnosis, lamotrigine, and benzodiazepines, were associated with remission. CONCLUSIONS: This study shows that psychotic subtype of depression and older age are clinically relevant predictors of a beneficial ECT effect. Additionally, ECT outcomes can be further improved by optimizing the treatment technique and concomitant medication.

Trace element and isotope deposition across the air-sea interface: progress and research needs.

The importance of the atmospheric deposition of biologically essential trace elements, especially iron, is widely recognized, as are the difficulties of accurately quantifying the rates of trace element wet and dry deposition and their fractional solubility. This paper summarizes some of the recent progress in this field, particularly that driven by the GEOTRACES, and other, international research programmes. The utility and limitations of models used to estimate atmospheric deposition flux, for example, from the surface ocean distribution of tracers such as dissolved aluminium, are discussed and a relatively new technique for quantifying atmospheric deposition using the short-lived radionuclide beryllium-7 is highlighted. It is proposed that this field will advance more rapidly by using a multi-tracer approach, and that aerosol deposition models should be ground-truthed against observed aerosol concentration data. It is also important to improve our understanding of the mechanisms and rates that control the fractional solubility of these tracers. Aerosol provenance and chemistry (humidity, acidity and organic ligand characteristics) play important roles in governing tracer solubility. Many of these factors are likely to be influenced by changes in atmospheric composition in the future. Intercalibration exercises for aerosol chemistry and fractional solubility are an essential component of the GEOTRACES programme.This article is part of the themed issue 'Biological and climatic impacts of ocean trace element chemistry'.

Trisomy 21 mosaicism: we may all have a touch of Down syndrome.

Ever increasing sophistication in the application of new analytical technology has revealed that our genomes are much more fluid than was contemplated only a few years ago. More specifically, this concerns interindividual variation in copy number (CNV) of structural chromosome aberrations, i.e. microdeletions and microduplications. It is important to recognize that in this context, we still lack basic knowledge on the impact of the CNV in normal cells from individual tissues, including that of whole chromosomes (aneuploidy). Here, we highlight this challenge by the example of the very first chromosome aberration identified in the human genome, i.e. an extra chromosome 21 (trisomy 21, T21), which is causative of Down syndrome (DS). We consider it likely that most, if not all, of us are T21 mosaics, i.e. everyone carries some cells with an extra chromosome 21, in some tissues. In other words, we may all have a touch of DS. We further propose that the occurrence of such tissue-specific T21 mosaicism may have important ramifications for the understanding of the pathogenesis, prognosis and treatment of medical problems shared between people with DS and those in the general non-DS population.

Clinical spectrum of immunodeficiency, centromeric instability and facial dysmorphism (ICF syndrome).

BACKGROUND: Immunodeficiency, centromeric instability and facial dysmorphism (ICF syndrome) is a rare autosomal recessive disease characterised by facial dysmorphism, immunoglobulin deficiency and branching of chromosomes 1, 9 and 16 after PHA stimulation of lymphocytes. Hypomethylation of DNA of a small fraction of the genome is an unusual feature of ICF patients which is explained by mutations in the DNA methyltransferase gene DNMT3B in some, but not all, ICF patients. OBJECTIVE: To obtain a comprehensive description of the clinical features of this syndrome as well as genotype-phenotype correlations in ICF patients. METHODS: Data on ICF patients were obtained by literature search and additional information by means of questionnaires to corresponding authors. RESULTS AND CONCLUSIONS: 45 patients all with proven centromeric instability were included in this study. Facial dysmorphism was found to be a common characteristic (n = 41/42), especially epicanthic folds, hypertelorism, flat nasal bridge and low set ears. Hypo- or agammaglobulinaemia was demonstrated in nearly all patients (n = 39/44). Opportunistic infections were seen in several patients, pointing to a T cell dysfunction. Haematological malignancy was documented in two patients. Life expectancy of ICF patients is poor, especially those with severe infections in infancy or chronic gastrointestinal problems and failure to thrive. Early diagnosis of ICF is important since early introduction of immunoglobulin supplementation can improve the course of the disease. Allogeneic stem cell transplantation should be considered as a therapeutic option in patients with severe infections or failure to thrive. Only 19 of 34 patients showed mutations in DNMT3B, suggesting genetic heterogeneity. No genotype-phenotype correlation was found between patients with and without DNMT3B mutations.

Nucleocapsid protein VP15 is the basic DNA binding protein of white spot syndrome virus of shrimp.

White spot syndrome virus (WSSV) is type species of the genus Whispovirus of the new family Nimaviridae. Despite the elucidation of its genomic sequence, very little is known about the virus as only 6% of its ORFs show homology to known genes. One of the structural virion proteins, VP15, is part of the nucleocapsid of the virus and shows homology to some putative baculovirus DNA binding proteins. These DNA-binding or histone-like proteins are thought to be involved in the condensation and packaging of the genome in the nucleocapsid. Using bacterially expressed VP15 fusion proteins in ELISA and Far-Western experiments showed that VP15 interacts with itself, forming homomultimers, but not with the other major structural proteins of the WSSV virion. Antibodies against phosphorylated proteins revealed that VP15 originating from different sources was not phosphorylated. WSSV VP15 binds non-specifically to double-stranded DNA, but has a clear preference to supercoiled DNA suggesting that VP15 is involved in the packaging of the WSSV genome in the nucleocapsid. This research shed further light on the composition of WSSV virions and the function of one of its nucleocapsid proteins.

DNMT3B mutations and DNA methylation defect define two types of ICF syndrome.

ICF syndrome is a rare autosomal recessive disease characterized by variable immunodeficiency, centromeric instability, and facial abnormalities. Mutations in the catalytic domain of DNMT3B, a gene encoding a de novo DNA methyltransferase, have been recognized in a subset of patients. ICF syndrome is a genetic disease directly related to a genomic methylation defect that mainly affects classical satellites 2 and 3, both components of constitutive heterochromatin. The variable incidence of DNMT3B mutations and the differential methylation defect of alpha satellites allow the identification of two types of patients, both showing an undermethylation of classical satellite DNA. This classification illustrates the specificity of the methylation process and raises questions about the genetic heterogeneity of the ICF syndrome.

Inter-sex variation in synaptonemal complex lengths largely determine the different recombination rates in male and female germ cells.

Meiotic chromosomes in human oocytes are packaged differently than in spermatocytes at the pachytene stage of meiosis I, when crossing-over takes place. Thus the meiosis-specific pairing structure, the synaptonemal complex (SC), is considerably longer in oocytes in comparison to spermatocytes. The aim of the present study was to examine the influence of this length factor on meiotic recombination in male and female human germ cells. The positions of crossovers were identified by the DNA mismatch repair protein MLH1. Spermatocytes have approximately 50 crossovers per cell in comparison to more than 70 in oocytes. Analyses of inter-crossover distances (and presumptively crossover interference) along SCs suggested that while there might be inter-individual variation, there was no consistent difference between sexes. Thus the higher rate of recombination in human oocytes is not a consequence of more closely spaced crossovers along the SCs. The rate of recombination per unit length of SC is higher in spermatocytes than oocytes. However, when the so-called obligate chiasma is excluded from the analysis, then the rates of recombination per unit length of SC are essentially identical in the two sexes. Our analyses indicate that the inter-sex difference in recombination is largely a consequence of the difference in meiotic chromosome architecture in the two sexes. We propose that SC length per se, and therefore the size of the physical platform for crossing-over (and not the DNA content) is the principal factor determining the difference in rate of recombination in male and female germ cells. A preliminary investigation of SC loop size by fluorescence in situ hybridization (FISH) indicated loops may be shorter in oocytes than in spermatocytes.

The initiation of homologous chromosome synapsis in mouse fetal oocytes is not directly driven by centromere and telomere clustering in the bouquet.

We investigated the behaviour of centromeres and distal telomeres during the initial phases of female meiosis in mice. In particular, we wished to determine whether clustering of centromeres and telomeres (bouquet formation) played the same crucial role in homologous chromosome pairing in female meiosis as it does in the male. We found that synapsis (intimate homologous chromosome pairing) is most frequently initiated in the interstitial regions of homologous chromosomes, apparently ahead of the distal regions. The proximal ends of the chromosomes appear to be disfavoured for synaptic initiation. Moreover, initiation of synapsis occurred in oocytes that showed little or no evidence of bouquet formation. A bouquet was present in a substantial proportion of cells at mid to late zygotene, and was still present in some pachytene oocytes. This pattern of bouquet formation and pairing initiation is in stark contrast to that previously described in the male mouse. We propose that although dynamic movements of centromeres and telomeres to form clusters may facilitate alignment of homologues or homologous chromosome segments during zygotene, in the female mouse positional control of synaptic initiation is dependent on some other mechanism.

Genetic variation among isolates of White spot syndrome virus.

White spot syndrome virus (WSSV), member of a new virus family called Nimaviridae, is a major scourge in worldwide shrimp cultivation. Geographical isolates of WSSV identified so far are very similar in morphology and proteome, and show little difference in restriction fragment length polymorphism (RFLP) pattern. We have mapped the genomic differences between three completely sequenced WSSV isolates, originating from Thailand (WSSV-TH), China (WSSV-CN) and Taiwan (WSSV-TW). Alignment of the genomic sequences of these geographical isolates revealed an overall nucleotide identity of 99.32%. The major difference among the three isolates is a deletion of approximately 13 kb (WSSV-TH) and 1 kb (WSSV-CN), present in the same genomic region, relative to WSSV-TW. A second difference involves a genetically variable region of about 750 bp. All other variations >2 bp between the three isolates are located in repeat regions along the genome. Except for the homologous regions ( hr1, hr3, hr8 and hr9), these variable repeat regions are almost exclusively located in ORFs, of which the genomic repeat regions in ORF75, ORF94 and ORF125 can be used for PCR based classification of WSSV isolates in epidemiological studies. Furthermore, the comparison identified highly invariable genomic loci, which may be used for reliable monitoring of WSSV infections and for shrimp health certification.

Meiotic chromosome pairing in fetal oocytes of trisomy 21 human females.

The influence of trisomy on meiotic chromosome association and synapsis was studied in oocytes of two trisomy 21 fetuses. The patterns of association of the three chromosomes 21 were determined by analysis of late zygotene to early diplotene fetal oocytes after immunofluorescent staining of synaptonemal complexes. The identity of chromosome 21 was confirmed using FISH with either a whole chromosome 21 paint or an alpha-satellite DNA repeat probe. In both fetuses, a wide variety of configurations was present at pachytene. The most common configurations were a trivalent (35.5% and 51.6% of analyzable cells) and a bivalent plus univalent (62.9% and 45.2%). These different frequencies between the fetuses were not significant. Trivalents showed either triple synapsis or double synapsis with pairing-partner switches. The extent of triple synapsis varied from a short segment, either terminal or interstitial, to the whole chromosome length. Through use of immunofluorescent staining of the centromeres, we identified novel types of abnormal chromosome behavior in trisomy 21 fetal oocytes. Thus, we found that 6/41 trivalents had one of the chromosomes associated "out of register," i.e., in a nonhomologous fashion, with its two homologs. Likewise, we found three cells with bivalent plus univalent configurations, in which the univalent showed self-synapsis. The presence of three copies of chromosome 21 therefore results not only in the formation of complex and highly variable synaptic associations but also causes a significant increase in the occurrence of nonhomologous synapsis in human fetal oocytes.

Growth factors promote meiosis in mouse fetal ovaries in vitro.

Mouse fetal ovaries were cultured to investigate germ cell development in the presence of a combination of the growth factors (GFs) stem cell factor, insulin-like growth factor-1 and leukaemia inhibitory factor. Ovaries were isolated from fetal mice at 13 and 14 days post-coitum (dpc) and cultured to the equivalent of 17 dpc. Culture conditions comprised minimal essential medium-alpha plus 5% fetal calf serum, with or without GFs. Oocytes were assessed using immunofluorescence to illustrate synaptonemal complexes and recombination foci. The proportions of pachytene cells in freshly isolated 13, 14 and 17 dpc ovaries were 0, 8 and 74% respectively. There was a significant (P < 0.0001) increase in the number of pachytene cells after 4 days culture with GFs, with 24% of germ cells from 13 dpc ovaries reaching pachytene. In contrast, no pachytene cells were detected in cultures of 13 dpc ovaries without GFs. After 3 days in culture with GFs, 38% of germ cells from 14 dpc ovaries were at pachytene compared with 19% without GFs. In conclusion, we have demonstrated positive effects of GFs upon oocyte formation by meiosis in vitro. The observed results could be explained by an increased survival of premeiotic oogonia entering meiosis, or by effects on oocytes already in early meiosis.

MECP2 gene mutation analysis in the British and Italian Rett Syndrome patients: hot spot map of the most recurrent mutations and bioinformatic analysis of a new MECP2 conserved region.

Rett syndrome (RTT) is an X-linked dominant neurological disorder, which appears to be the most common genetic cause of profound combined intellectual and physical disability in Caucasian females. This syndrome has been associated with mutations of the MECP2 gene, a transcriptional repressor of unknown target genes. We report a detailed mutational analysis of a large cohort of RTT patients from the UK and Italy. This study has permitted us to produce a hot spot map of the mutations identified. Bioinformatic analysis of the mutations, taking advantage of structural and evolutionary data, leads us to postulate the existence of a new functional domain in the MeCP2 protein, conserved among brain-specific regulatory factors.

GELFISH--graphical environment for labelling fluorescence in-situ hybridization images.

Signal (dot) counting in fluorescence in-situ hybridization (FISH) images that relies on an automatic focusing method for obtaining clearly defined images is a time-consuming procedure prone to errors. Our recently developed system has dispensed with automatic focusing, and instead relies on a neural network classifying focused and unfocused signals into valid and artefact data, respectively, and thereby discriminating between in- and out-of-focus images. However, to train the classifier accurate labelling of the image signals is required. GELFISH is a Graphical Environment for Labelling FISH images that enables the rejection of unanalysable nuclei and labelling of FISH signals simply and rapidly. GELFISH is flexible and can be modified easily for additional FISH applications. Also, implemented using popular software, the environment can be employed on any computer by any user. Finally, GELFISH is proposed in controlling a classifier-based dot counting system.

The white spot syndrome virus DNA genome sequence.

White spot syndrome virus (WSSV) is at present a major scourge to worldwide shrimp cultivation. We have determined the entire sequence of the double-stranded, circular DNA genome of WSSV, which contains 292,967 nucleotides encompassing 184 major open reading frames (ORFs). Only 6% of the WSSV ORFs have putative homologues in databases, mainly representing genes encoding enzymes for nucleotide metabolism, DNA replication, and protein modification. The remaining ORFs are mostly unassigned, except for five, which encode structural virion proteins. Unique features of WSSV are the presence of a very long ORF of 18,234 nucleotides, with unknown function, a collagen-like ORF, and nine regions, dispersed along the genome, each containing a variable number of 250-bp tandem repeats. The collective information on WSSV and the phylogenetic analysis on the viral DNA polymerase suggest that WSSV differs profoundly from all presently known viruses and that it is a representative of a new virus family.