Molecular and clinical descriptions of patients with GABAA receptor gene variants (GABRA1, GABRB2, GABRB3, GABRG2): A cohort study, review of literature, and genotype-phenotype correlation

OBJECTIVE

γ-Aminobutyric acid (GABA)_A -receptor subunit variants have recently been associated with neurodevelopmental disorders and/or epilepsy. The phenotype linked with each gene is becoming better known. Because of the common molecular structure and physiological role of these phenotypes, it seemed interesting to describe a putative phenotype associated with GABA_A -receptor-related disorders as a whole and seek possible genotype-phenotype correlations.

METHODS

We collected clinical, electrophysiological, therapeutic, and molecular data from patients with GABA_A -receptor subunit variants (GABRA1, GABRB2, GABRB3, and GABRG2) through a national French collaboration using the EPIGENE network and compared these data to the one already described in the literature.

RESULTS

We gathered the reported patients in three epileptic phenotypes: 15 patients with fever-related epilepsy (40%), 11 with early developmental epileptic encephalopathy (30%), 10 with generalized epilepsy spectrum (27%), and 1 patient without seizures (3%). We did not find a specific phenotype for any gene, but we showed that the location of variants on the transmembrane (TM) segment was associated with a more severe phenotype, irrespective of the GABA_A -receptor subunit gene, whereas N-terminal variants seemed to be related to milder phenotypes.

SIGNIFICANCE

GABA_A -receptor subunit variants are associated with highly variable phenotypes despite their molecular and physiological proximity. None of the genes described here was associated with a specific phenotype. On the other hand, it appears that the location of the variant on the protein may be a marker of severity. Variant location may have important weight in the development of targeted therapeutics.

Novel partial loss-of-function variants in the tyrosyl-tRNA synthetase 1 (YARS1) gene involved in multisystem disease

Cytoplasmic aminoacyl-tRNA synthetases (ARSs) are emerging as a cause of numerous rare inherited diseases. Recently, biallelic variants in tyrosyl-tRNA synthetase 1 (YARS1) have been described in ten patients of three families with multi-systemic disease (failure to thrive, developmental delay, liver dysfunction, and lung cysts). Here, we report an additional subject with overlapping clinical findings, heterozygous for two novel variants in tyrosyl-tRNA synthetase 1 (NM_003680.3(YARS1):c.176T>C; p.(Ile59Thr) and NM_003680.3(YARS1):c.237C>G; p.(Tyr79*) identified by whole exome sequencing. The p.Ile59Thr variant is located in the highly conserved aminoacylation domain of the protein. Compared to subjects previously described, this patient presents a much more severe condition. Our findings support implication of two novel YARS1 variants in these disorders. Furthermore, we provide evidence for a reduced protein abundance in cells of the patient, in favor of a partial loss-of-function mechanism.

Correction: IQSEC2-related encephalopathy in males and females: a comparative study including 37 novel patients

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Clinical study of 19 patients with SCN8A-related epilepsy: Two modes of onset regarding EEG and seizures

OBJECTIVE

To describe the mode of onset of SCN8A-related severe epilepsy in order to facilitate early recognition, and eventually early treatment with sodium channel blockers.

METHODS

We reviewed the phenotype of patients carrying a mutation in the SCN8A gene, among a multicentric cohort of 638 patients prospectively followed by several pediatric neurologists. We focused on the way clinicians made the diagnosis of epileptic encephalopathy, the very first symptoms, electroencephalography (EEG) findings, and seizure types. We made genotypic/phenotypic correlation based on epilepsy-associated missense variant localization over the protein.

RESULTS

We found 19 patients carrying a de novo mutation of SCN8A, representing 3% of our cohort, with 9 mutations being novel. Age at onset of epilepsy was 1 day to 16 months. We found two modes of onset: 12 patients had slowly emerging onset with rare and/or subtle seizures and normal interictal EEG (group 1). The first event was either acute generalized tonic-clonic seizure (GTCS; Group 1a, n = 6) or episodes of myoclonic jerks that were often mistaken for sleep-related movements or other movement disorders (Group 1b, n = 6). Seven patients had a sudden onset of frequent tonic seizures or epileptic spasms with abnormal interictal EEG leading to rapid diagnosis of epileptic encephalopathy. Sodium channel blockers were effective or nonaggravating in most cases.

SIGNIFICANCE

SCN8A is the third most prevalent early onset epileptic encephalopathy gene and is associated with two modes of onset of epilepsy.

IQSEC2-related encephalopathy in males and females: a comparative study including 37 novel patients

Purpose

Variants in IQSEC2, escaping X inactivation, cause X-linked intellectual disability with frequent epilepsy in males and females. We aimed to investigate sex-specific differences.

Methods

We collected the data of 37 unpublished patients (18 males and 19 females) with IQSEC2 pathogenic variants and 5 individuals with variants of unknown significance and reviewed published variants. We compared variant types and phenotypes in males and females and performed an analysis of IQSEC2 isoforms.

Results

IQSEC2 pathogenic variants mainly led to premature truncation and were scattered throughout the longest brain-specific isoform, encoding the synaptic IQSEC2/BRAG1 protein. Variants occurred de novo in females but were either de novo (2/3) or inherited (1/3) in males, with missense variants being predominantly inherited. Developmental delay and intellectual disability were overall more severe in males than in females. Likewise, seizures were more frequently observed and intractable, and started earlier in males than in females. No correlation was observed between the age at seizure onset and severity of intellectual disability or resistance to antiepileptic treatments.

Conclusion

This study provides a comprehensive overview of IQSEC2-related encephalopathy in males and females, and suggests that an accurate dosage of IQSEC2 at the synapse is crucial during normal brain development.

Missense mutation of TTC7A mimicking tricho-hepato-enteric (SD/THE) syndrome in a patient with very-early onset inflammatory bowel disease

Tricho-hepato-enteric syndrome (SD/THE) and Multiple intestinal atresia with combined immune deficiency (MIA-CID) are autosomal recessive disorders that present immunological and gastrointestinal features. There are two different phenotypes of patients with TTC7A mutations: the severe form, caused by null mutations and leading to the classical MIA-CID; and the mild form, caused by missense mutations and leading to predominant features of VEO-IBD, less severe immunological involvement and hair abnormalities. We expand the knowledge about TTC7A deficiency, describing a patient with the mild phenotype of TTC7A deficiency but presenting overlapping features of SD/THE and MIA-CID: intestinal atresia and inflammatory bowel disease evocative of MIA-CID, but also dental abnormalities, huge forehead, liver abnormalities, autoimmune thyroiditis and hypogammaglobulinemia, evocative of SD/THE.

[NISCH syndrome, a rare cause of neonatal cholestasis: A case report]

NISCH syndrome is a rare autosomal recessive disease. It is characterized by scalp hypotrichosis, scarring alopecia, ichthyosis, and neonatal sclerosing cholangitis. It is caused by mutations in the CLDN1 gene encoding the claudin-1 protein, which is located at tight junctions. Fifteen cases have been reported to date and three different mutations have been identified. We report on the case of a 2-year-old boy from a consanguineous Moroccan family, presenting with NISCH syndrome and carrying the so-called Moroccan homozygous mutation (c.200-201delTT). The patient presented with the characteristic symptoms of the syndrome and a favorable progression with normalization of hepatic analyses under symptomatic treatment (vitamin supplementation and ursodeoxycholic acid). The currently limited availability of clinical and therapeutic data does not allow accurate prediction of the course of the disease and short- and long-term prognosis. Moreover, substantial interindividual variability has been reported. Description of new cases will provide new insights into the understanding and the overall management of this syndrome, the course of which remains elusive.

A Kv7.2 mutation associated with early onset epileptic encephalopathy with suppression-burst enhances Kv7/M channel activity

Mutations in the KCNQ2 gene encoding the voltage-gated potassium channel subunit Kv7.2 cause early onset epileptic encephalopathy (EOEE). Most mutations have been shown to induce a loss of function or to affect the subcellular distribution of Kv7 channels in neurons. Herein, we investigated functional consequences and subcellular distribution of the p.V175L mutation of Kv7.2 (Kv7.2(V175L) ) found in a patient presenting EOEE. We observed that the mutation produced a 25-40 mV hyperpolarizing shift of the conductance-voltage relationship of both the homomeric Kv7.2(V175L) and heteromeric Kv7.2(V175L) /Kv7.3 channels compared to wild-type channels and a 10 mV hyperpolarizing shift of Kv7.2(V175L) /Kv7.2/Kv7.3 channels in a 1:1:2 ratio mimicking the patient situation. Mutant channels also displayed faster activation kinetics and an increased current density that was prevented by 1 μm linopirdine. The p.V175L mutation did not affect the protein expression of Kv7 channels and its localization at the axon initial segment. We conclude that p.V175L is a gain of function mutation. This confirms previous observations showing that mutations having opposite consequences on M channels can produce EOEE. These findings alert us that drugs aiming to increase Kv7 channel activity might have adverse effects in EOEE in the case of gain-of-function variants.

[Use of hyaluronidase to correct hyaluronic acid injections in aesthetic medicine]

Hyaluronic acid (HA) is the most commonly used filler in aesthetic medicine. However, overcorrections are frequent even with experienced practitioner. Hyaluronidase is an enzyme that hydrolyzes HA. Hyaluronidase has been recently proposed to correct unsatisfactory results of HA injections in aesthetic medicine (overcorrection, asymmetry, Tyndall effect) and to treat immediate complications such as arterial or venous thrombosis. The objective of this technical note was to summarize the literature data regarding the efficacy, safety and technique of use of hyaluronidase. Hyaluronidase may be responsible for allergies. The practitioner should take this risk and the possible drug interactions into account before using this antidote in order to weigh up the risk/benefit ratio.

Is there a justification for hysterectomy in patients with borderline ovarian tumors?

OBJECTIVE

To determine the frequency of uterine involvement in patients with borderline ovarian tumors (BOT) and to evaluate the recurrence risk and survival after hysterectomy.

MATERIALS AND METHODS

In two French hospitals: A tertiary referral centre (University hospital centre of Tours, France) and the Alliance community hospital of Tours (France), we reviewed data of consecutive women undergoing surgery for presumed stage I BOT between January 1997 and December 2012. Patients were divided into two groups: patients treated with fertility sparing surgery (group 1) and those treated with radical surgery (group 2).

RESULTS

A total of 135 patients were evaluated. 35 had fertility sparing surgery, 81 had radical surgery with hysterectomy and 19 had previous hysterectomy for other reasons. There were more recurrent borderline ovarian disease and more ovarian invasive disease developed in group 1 (p = 0.02, p = 0.04, respectively). Hysterectomy affected favorably borderline disease-free survival, OR = 0.09 95%CI (0.005-0.69), p = 0.04, but perceived benefits may be related to bilateral salpingo-oophorectomy and not hysterectomy directly.

Epileptic patients with de novo STXBP1 mutations: Key clinical features based on 24 cases

OBJECTIVE

Mutations in the syntaxin binding protein 1 gene (STXBP1) have been associated mostly with early onset epileptic encephalopathies (EOEEs) and Ohtahara syndrome, with a mutation detection rate of approximately 10%, depending on the criteria of selection of patients. The aim of this study was to retrospectively describe clinical and electroencephalography (EEG) features associated with STXBP1-related epilepsies to orient molecular screening.

METHODS

We screened STXBP1 in a cohort of 284 patients with epilepsy associated with a developmental delay/intellectual disability and brain magnetic resonance imaging (MRI) without any obvious structural abnormality. We reported on patients with a mutation and a microdeletion involving STXBP1 found using array comparative genomic hybridization (CGH).

RESULTS

We found a mutation of STXBP1 in 22 patients and included 2 additional patients with a deletion including STXBP1. In 22 of them, epilepsy onset was before 3 months of age. EEG at onset was abnormal in all patients, suppression-burst and multifocal abnormalities being the most common patterns. The rate of patients carrying a mutation ranged from 25% in Ohtahara syndrome to <5% in patients with an epilepsy beginning after 3 months of age. Epilepsy improved over time for most patients, with an evolution to West syndrome in half. Patients had moderate to severe developmental delay with normal head growth. Cerebellar syndrome with ataxic gait and/or tremor was present in 60%.

SIGNIFICANCE

Our data confirm that STXBP1 mutations are associated with neonatal-infantile epileptic encephalopathies. The initial key features highlighted in the cohort of early epileptic patients are motor seizures either focal or generalized, abnormal initial interictal EEG, and normal head growth. In addition, we constantly found an ongoing moderate to severe developmental delay with normal head growth. Patients often had ongoing ataxic gait with trembling gestures. Altogether these features should help the clinician to consider STXBP1 molecular screening.

Incidence of ATRX mutations in myelodysplastic syndromes, the value of microcytosis

Acquired α-thalassemia myelodysplastic syndrome (MDS) (ATMDS) is an acquired syndrome characterized by a somatic point mutation or splicing defect in the ATRX gene in patients with myeloid disorders, primarily MDS. In a large MDS patient series, the incidence of ATMDS was below 0.5%. But no large series has yet assessed the incidence of ATMDS in microcytic MDS. In this study, we focused on patients with MDS and unexplained microcytosis, which was defined as absence of iron deficiency, inflammatory disease, or history of inherited hemoglobinopathy. Our data confirm the low frequency of ATRX mutations in MDS: 0% in an unselected clinical trial cohort of 80 low risk MDS, 0.2-0.8% in a multicenter registry of 2,980 MDS and 43% of MDS with unexplained microcytosis in this same registry. In addition, we reported four novel mutations of the ATRX gene in ATMDS. This study further determines the frequency of ATRX mutations and highlights the importance of microcytosis to detect ATRX mutations within MDS patients.

Malignant Melanoma Arising in Patients with a Large Congenital Melanocytic Naevus: Retrospective Study of 10 Cases with Cytogenetic Analysis

Large congenital melanocytic naevi (LCMN) represent the main risk factor for development of melanoma in childhood. This retrospective study of 10 cases of melanoma in patients with LCMN used fluorescence in situ hybridization (FISH) and comparative genomic hybridization (CGH) (6 cases) to elucidate the clinical, histological, and cytogenetic characteristics of this rare disorder. Six melanomas were found within the LCMN, the others in lymph nodes, subcutis and brain. The LCMN was located on the trunk in 8 cases, with satellite naevi in 6 cases. Two distinct groups emerged: 5 melanomas that developed before the age of 10 years and the other after 20 years. The mortality rate was 60% and clearly correlated with clinical stage at diagnosis. Histological diagnosis was difficult in only 2 patients in whom neither immunohistochemistry nor FISH were helpful. Otherwise, CGH showed a high number of chromosomal aberrations leading to a formal diagnosis.

Increased Susceptibility to Aphids of Flowering Wheat Plants Exposed to Low Temperatures

Frost is known to directly affect flowering wheat plants (Triticum aestivum L.) and lead to reduced grain yield. Additionally, it may increase wheat susceptibility to economically important pests, such as aphids (Hemiptera: Aphididae). Wheat plants at flowering stage were exposed to one of the three temperature treatments: ambient (11-12°C), 0°C, and -3°C for 60 min. Preference (3-choice) and performance (no-choice) bioassays with aphids (Rhopalosiphum padi L.) were conducted 1, 3, 6, and 12 d after temperature treatments to assess effects of temperature-induced stress over time. As an initial feasibility study of using remote sensing technologies to detect frost-induced stress in flowering wheat plants, hyperspectral imaging data were acquired from wheat plants used in preference bioassays. Element analysis of wheat plants was included to determine the effect of temperature-induced stress on the nutritional composition of flowering wheat plants. The results from this study support the following cause-effect scenario: a 60-min exposure to low temperatures caused a significant decrease in potassium and copper content of wheat plants 6 d after temperature exposure, and it coincided with a marked increase in preference by aphids of wheat plants. The preference exhibited by aphids correlated positively with performance of aphids, so the preference-performance hypothesis was confirmed and possibly driven by potassium and copper content of wheat plants. In addition, we demonstrated that hyperspectral imaging data can be used to detect frost-induced susceptibility to aphid infestation in flowering wheat plants. These findings justify further research into airborne remote sensing of frost-induced stress and the possible secondary effects on crop susceptibility to arthropod pests.

A recurrent KCNQ2 pore mutation causing early onset epileptic encephalopathy has a moderate effect on M current but alters subcellular localization of Kv7 channels

Mutations in the KCNQ2 gene encoding the voltage-dependent potassium M channel Kv7.2 subunit cause either benign epilepsy or early onset epileptic encephalopathy (EOEE). It has been proposed that the disease severity rests on the inhibitory impact of mutations on M current density. Here, we have analyzed the phenotype of 7 patients carrying the p.A294V mutation located on the S6 segment of the Kv7.2 pore domain (Kv7.2(A294V)). We investigated the functional and subcellular consequences of this mutation and compared it to another mutation (Kv7.2(A294G)) associated with a benign epilepsy and affecting the same residue. We report that all the patients carrying the p.A294V mutation presented the clinical and EEG characteristics of EOEE. In CHO cells, the total expression of Kv7.2(A294V) alone, assessed by western blotting, was only 20% compared to wild-type. No measurable current was recorded in CHO cells expressing Kv7.2(A294V) channel alone. Although the total Kv7.2(A294V) expression was rescued to wild-type levels in cells co-expressing the Kv7.3 subunit, the global current density was still reduced by 83% compared to wild-type heteromeric channel. In a configuration mimicking the patients' heterozygous genotype i.e., Kv7.2(A294V)/Kv7.2/Kv7.3, the global current density was reduced by 30%. In contrast to Kv7.2(A294V), the current density of homomeric Kv7.2(A294G) was not significantly changed compared to wild-type Kv7.2. However, the current density of Kv7.2(A294G)/Kv7.2/Kv7.3 and Kv7.2(A294G)/Kv7.3 channels were reduced by 30% and 50% respectively, compared to wild-type Kv7.2/Kv7.3. In neurons, the p.A294V mutation induced a mislocalization of heteromeric mutant channels to the somato-dendritic compartment, while the p.A294G mutation did not affect the localization of the heteromeric channels to the axon initial segment. We conclude that this position is a hotspot of mutation that can give rise to a severe or a benign epilepsy. The p.A294V mutation does not exert a dominant-negative effect on wild-type subunits but alters the preferential axonal targeting of heteromeric Kv7 channels. Our data suggest that the disease severity is not necessarily a consequence of a strong inhibition of M current and that additional mechanisms such as abnormal subcellular distribution of Kv7 channels could be determinant.

Similar early characteristics but variable neurological outcome of patients with a de novo mutation of KCNQ2

Background

Early onset epileptic encephalopathies (EOEEs) are dramatic heterogeneous conditions in which aetiology, seizures and/or interictal EEG have a negative impact on neurological development. Several genes have been associated with EOEE and a molecular diagnosis workup is challenging since similar phenotypes are associated with mutations in different genes and since mutations in one given gene can be associated with very different phenotypes. Recently, de novo mutations in KCNQ2, have been found in about 10% of EOEE patients. Our objective was to confirm that KCNQ2 was an important gene to include in the diagnosis workup of EOEEs and to fully describe the clinical and EEG features of mutated patients.

Methods

We have screened KCNQ2 in a cohort of 71 patients with an EOEE, without any brain structural abnormality. To be included in the cohort, patient’s epilepsy should begin before three months of age and be associated with abnormal interictal EEG and neurological impairment. Brain MRI should not show any structural abnormality that could account for the epilepsy.

Results

Out of those 71 patients, 16 had a de novo mutation in KCNQ2 (23%). Interestingly, in the majority of the cases, the initial epileptic features of these patients were comparable to those previously described in the case of benign familial neonatal epilepsy (BFNE) also caused by KCNQ2 mutations. However, in contrast to BFNE, the interictal background EEG was altered and displayed multifocal spikes or a suppression-burst pattern. The ongoing epilepsy and development were highly variable but overall severe: 15/16 had obvious cognitive impairment, half of the patients became seizure-free, 5/16 could walk before the age of 3 and only 2/16 patient acquired the ability to speak.

Conclusion

This study confirms that KCNQ2 is frequently mutated de novo in neonatal onset epileptic encephalopathy. We show here that despite a relatively stereotyped beginning of the condition, the neurological and epileptic evolution is variable.

[Leg ulcer associated with type I cryoglobulinaemia due to incipient B-cell lymphoma]

BACKGROUND

Skin lesions are frequent in monoclonal cryoglobulinaemia and may be the first sign of B-cell lymphoma, especially multiple myeloma, Waldenström's macroglobulinaemia and B-cell chronic lymphocytic leukaemia.

PATIENTS AND METHODS

A 74-year-old woman with no prior medical history presented with necrotic leg ulcer. Skin biopsy showed dermal angiomatosis with numerous PAS+ thromboses, associated with monoclonal intravascular deposits of IgM kappa, indicating monoclonal cryoglobulin, which was confirmed by laboratory tests. Subsequent blood immunophenotyping revealed an inconspicuous circulating monoclonal CD5(+) B-cell population and small B-cell clusters in the bone marrow, while the B-cell count was normal and no lymphadenopathy or splenomegaly were present. Overall, these findings indicated a small B-cell lymphoma, classed as non-MALT marginal zone lymphoma on the WHO classification, at a very early stage of development. The patient was first treated by cyclophosphamide and oral steroids without success. Subsequent administration of six cycles of rituximab, cyclophosphamide, vincristine and prednisone (RCVP) led to remission of her leg ulcer, cryoglobulinaemia and lymphoma.

CONCLUSION

Skin biopsies of necrotic ulcers should undergo routine screening for intravascular deposits of type 1 cryoglobulin. Leg ulcers due to monoclonal cryoglobulinaemia may reveal incipient marginal zone B-cell lymphoma at the stage of circulating monoclonal lymphocytosis.

Molecular screening of MECP2 gene in a cohort of Lebanese patients suspected with Rett syndrome: report on a mild case with a novel indel mutation

BACKGROUND

Rett syndrome (RTT), an X-linked, dominant, neurodevelopment disorder represents 10% of female subjects with profound intellectual disability. Mutations in the MECP2 gene are responsible for up to 95% of the classical RTT cases, and nearly 500 different mutations distributed throughout the gene have been reported.

METHODS

We report here the molecular study of two isoforms, MECP2_e1 and MECP2_e2, in 45 Lebanese girls presenting developmental delay and at least one of the following features: microcephaly, neurodegeneration, abnormal behaviour, stereotypical hand movements, teeth grinding and difficulty in walking. Mutation screening was performed by denaturating high-performance liquid chromatography combined with direct sequencing.

RESULTS

Sixteen variants were noted, of which 14 have been previously reported: five suspected polymorphisms and nine mutations. Two variants were novel mutations in exon 4: c.1093_1095delGAG (p.E365del) and c.1164_1184delACCTCCACCTGAGCCCGAGAGinsCTGAGCCCCAGGACTTGAGCA (p.P388PfsX389). The deletion was found in an 8-year-old girl with typical clinical features of RTT. The indel was found in a 6-year-old girl with a very mild phenotype.

CONCLUSION

Genotype/phenotype correlation is discussed and the importance of a molecular study of MECP2 gene in patients with very mild features or a regression after the age of 2 is raised.

Reliability of a simple fluoroscopic method to study sagittal plane femorotibial contact changes in total knee arthroplasties during flexion

Clinical interest in sagittal plane kinematic analysis of the knee undergoing total knee replacement fosters the development of simple, reliable methods to estimate femorotibial contact in a regular clinical setting. In this study, the sagittal femorotibial contact was analysed in lateral X-rays and lateral fluoroscopic views, from extension to knee flexion. Quantitative and categorical data were obtained from these views by two different observers, and compared with data from direct views of the components. Interobserver and intermethod errors for quantitative and categorical data were evaluated based on correlation, kappa coefficient, and Bland-Altman graphs. Interobserver reproducibility of quantitative measurement from fluoroscopic views was r=0.96 while categorical assignment exhibited a kappa coefficient of 0.95. Reproducibility from plain radiographs was not so high, with a kappa coefficient of 0.64. High concordance was also obtained when the method was compared with the direct view of the implant, supporting these measurement techniques. Bland-Altman graphs confirmed the absence of bias in the intermethod comparison. Therefore, with the obvious limitation of rotational assessment, lateral fluoroscopic evaluation enhanced by a simple fitting technique can be used as a valuable tool for clinical evaluation of knee kinematics in the sagittal plane.

Partial duplications of the ATRX gene cause the ATR-X syndrome

ATR-X syndrome is a rare syndromic X-linked mental retardation disorder. We report that some of the patients suspected of ATR-X carry large intragenic duplications in the ATRX gene, leading to an absence of ATRX mRNA and of the protein. These findings underscore the need for including quantitative analyses to mutation analysis of the ATRX gene.

Mutations in PHD-like domain of the ATRX gene correlate with severe psychomotor impairment and severe urogenital abnormalities in patients with ATRX syndrome

Mutations in ATRX are associated with a wide and clinically heterogeneous spectrum of X-linked mental retardation syndromes. The ATRX protein, involved in chromatin remodelling, belongs to the family of SWI/SNF DNA helicases and contains a plant homeodomain (PHD)-like domain. To date, more than 60 different mutations have been reported in ATRX. One of them is recurrent and accounts for 20% of all the reported mutations, whereas all others are private. Most mutations are clustered in the two major functional domains, the helicase and the PHD-like domain. So far, no clear genotype-phenotype correlation has been established, with exception to the rare truncating mutations located at the C-terminal part of the protein, which are consistently associated with severe urogenital defects. In this study, we report the molecular analysis performed in 16 families positive for ATRX. Our findings indicate that, in addition to the previously described mutation 'hotspot' in the PHD-like domain, two other protein sections emerge as minor 'hotspots' in the helicase region encoded by exons 18-20 and 26-29, respectively, gathering 33% of all described mutations. Additionally, based on the clinical data collected for 22 patients from the 16 families, we observe that mutations in the PHD-like domain produce severe and permanent psychomotor deficiency, usually preventing patients from walking, as well as constant urogenital abnormalities, while mutations in the helicase domain lead to delayed but correct psychomotor acquisitions together with mild or absent urogenital abnormalities. In summary, mutations in the helicase domain are associated with milder phenotypes than mutations in the PHD-like domain.

MAU-8 is a Phosducin-like Protein required for G protein signaling in C. elegans

The mau-8(qm57) mutation inhibits the function of GPB-2, a heterotrimeric G protein beta subunit, and profoundly affects behavior through the Galphaq/Galphao signaling network in C. elegans. mau-8 encodes a nematode Phosducin-like Protein (PhLP), and the qm57 mutation leads to the loss of a predicted phosphorylation site in the C-terminal domain of PhLP that binds the Gbetagamma surface implicated in membrane interactions. In developing embryos, MAU-8/PhLP localizes to the cortical region, concentrates at the centrosomes of mitotic cells and remains associated with the germline blastomere. In adult animals, MAU-8/PhLP is ubiquitously expressed in somatic tissues and germline cells. MAU-8/PhLP interacts with the PAR-5/14.3.3 protein and with the Gbeta subunit GPB-1. In mau-8 mutants, the disruption of MAU-8/PhLP stabilizes the association of GPB-1 with the microtubules of centrosomes. Our results indicate that MAU-8/PhLP modulates G protein signaling, stability and subcellular location to regulate various physiological functions, and they suggest that MAU-8 might not be limited to the Galphaq/Galphao network.

Point processes for unsupervised line network extraction in remote sensing

This paper addresses the problem of unsupervised extraction of line networks (for example, road or hydrographic networks) from remotely sensed images. We model the target line network by an object process, where the objects correspond to interacting line segments. The prior model, called "Quality Candy," is designed to exploit as fully as possible the topological properties of the network under consideration, while the radiometric properties of the network are modeled using a data term based on statistical tests. Two techniques are used to compute this term: one is more accurate, the other more efficient. A calibration technique is used to choose the model parameters. Optimization is done via simulated annealing using a Reversible Jump Markov Chain Monte Carlo (RJMCMC) algorithm. We accelerate convergence of the algorithm by using appropriate proposal kernels. The results obtained on satellite and aerial images are quantitatively evaluated with respect to manual extractions. A comparison with the results obtained using a previous model, called the "Candy" model, shows the interest of adding quality coefficients with respect to interactions in the prior density. The relevance of using an offline computation of the data potential is shown, in particular, when a proposal kernel based on this computation is added in the RJMCMC algorithm.

Phenylphenols, biphenols, bisphenol-A and 4-tert-octylphenol exhibit alpha and beta estrogen activities and antiandrogen activity in reporter cell lines

We previously demonstrated the interactions of different chemical compounds with estrogen receptors ERalpha and ERbeta and the androgen receptor (AR) using different reporter cell lines. In this study, we characterize the ERalpha, ERbeta and AR activity of different biphenyls using the same tools. We provide evidence that several phenyl derivatives present both estrogenic and antiandrogenic activity. The extent of hydroxylation and the position of the hydroxyl function were important in determining their estrogenicity and antiandrogenicity. Of the tested compounds, bisphenol-A and 4,4' biphenol had very high estrogenic activity, although it was lower than that of the strong estrogenic alkylphenol, 4-tert-octylphenol. Bisphenol-A and 4,4' biphenol were able to activate ERs at concentrations lower than 1 microM, whereas the other compounds only activated at concentrations above 1 microM. Interestingly, 4,4' biphenol was a better agonist for ERbeta than for ERalpha. No androgenic activity was detected for any of these compounds. Bisphenol-A, 3-OH phenylphenol, 4-OH phenylphenol and 4,4' biphenol exhibited antiandrogenic activity close to that of 4-tert-octylphenol (IC(50) approximately 5 microM). In whole cell binding assays, these compounds displaced [3H] R1881 with Ki = 10 microM. Although these Ki values seem high in comparison with that of hydroxyflutamide (0.4 microM), one must keep in mind that environmental chemicals can accumulate in adipose tissues for several years. In conclusion, these environmental chemicals may have a negative impact on androgen action during fetal and post-natal life.

[Segmental rehabilitation in cardiac failure: short and long-term results]

Many patients with chronic cardiac failure may benefit from exercise rehabilitation. However, the usual protocols, which may lead to haemodynamic disturbances or induce arrhythmias, are rarely applicable in the most severe cases. Therefore, the authors developed a protocol of segmental rehabilitation where the same muscle groups as in global readaptation are involved, but successively and not simultaneously. This study included 25 patients in the NYHA class III. Many parameters were analysed before and after forty sessions. Although the resting isotopic ejection fraction (0.26 +/- 0.1 vs 0.27 +/- 0.11; p = NS), oxygen consumption at the ventilatory threshold (14.3 +/- 3.5 vs 18.3 +/- 5.2 ml/kg/min; p = NS) or at peak effort (17.4 +/- 4.7 versus 18.3 +/- 5.2 ml/kg/min, p = NS) were unchanged, three other parameters were significantly improved: the duration of exercise (9.2 +/- 2.4 vs 10.4 +/- 3.4 min; p < 0.02) maximum work load (3 046 +/- 1 510 vs 3 992 +/- 2 482; p < 0.01) and muscular force (151 +/- 35 versus 220 +/- 41 kg; p < 0.0001). In addition, after a follow-up period of 43 +/- 18 months, a close inverse relationship was observed between the gains obtained in terms of duration of exercise and maximum work load and the number of hospital readmissions. Similarly, the 10 patients having undergone rehabilitation with this protocol had 11.7 times fewer hospital readmissions than the other 15. Segmental rehabilitation would therefore seem to be a safe technique for patients with severe cardiac for significantly increasing exercise capacity and lowering the number of readmissions to hospital.

Vitreous fluorescein accumulation determined by in vivo fluorophotometry and by vitreous extraction in normal and diabetic rats

Vitreous fluorophotometry was performed on pigmented male rats (Piebald strain) 2 weeks after induction of diabetes by streptozotocin. In vivo fluorophotometry data were compared with measurements obtained by direct extraction of the vitreous 60 min after an intravenous injection of sodium fluorescein. In addition, the rate of fluorescein disappearance from blood plasma, plasma protein binding of fluorescein and the effect of insulin treatment of diabetic animals were investigated. Age-matched nondiabetic animals served as controls. In vivo fluorophotometric measurements showed a good correlation with fluorescein determinations after direct extraction of the vitreous. Vitreous fluorescein concentrations were similar in diabetic and normal rats and were strongly related to the dye plasma levels within each group of animals. In the diabetic rats, however, the elimination of plasma fluorescein was accelerated and the percentage of free fluorescein, as determined by ultrafiltration and equilibrium dialysis, was consistently higher (130-150% of controls). The ratios of vitreous to total or free plasma fluorescein levels were elevated in diabetic rats. Experimental data indicate that plasma concentration of free fluorescein is crucial for vitreous dye accumulation. Insulin treatment of diabetic rats markedly improved their metabolic state and normalized the plasma fluorescein elimination and the vitreous to plasma fluorescein concentration ratios. It is concluded that vitreous fluorophotometry can be adequately applied to pigmented rats, provided that plasma fluorescein elimination rate and protein binding are considered in the interpretation of the results, since both influence the vitreous fluorescein accumulation and both may be altered by disease and drug treatment.