Alu-repeat-induced deletions within the NCF2 gene causing p67-phox-deficient chronic granulomatous disease (CGD)

Mutations that impair expression or function of the components of the phagocyte NADPH oxidase complex cause chronic granulomatous disease (CGD), which is associated with life-threatening infections and dysregulated granulomatous inflammation. In five CGD patients from four consanguineous families of two different ethnic backgrounds, we found similar genomic homozygous deletions of 1,380 bp comprising exon 5 of NCF2, which could be traced to Alu-mediated recombination events. cDNA sequencing showed in-frame deletions of phase zero exon 5, which encodes one of the tandem repeat motifs in the tetratricopeptide (TPR4) domain of p67-phox. The resulting shortened protein (p67Delta5) had a 10-fold reduced intracellular half-life and was unable to form a functional NADPH oxidase complex. No dominant negative inhibition of oxidase activity by p67Delta5 was observed. We conclude that Alu-induced deletion of the TPR4 domain of p67-phox leads to loss of function and accelerated degradation of the protein, and thus represents a new mechanism causing p67-phox-deficient CGD.

Transient oligoarthritis of the lower extremity following influenza B virus infection: Case report

A 12-year-old girl developed influenza B virus infection proven by typical symptoms and detection of the virus in a nasopharyngeal swab by culture and PCR. Two weeks later she developed an otherwise unexplained transient oligoarthritis of small joints of the left foot. Influenza viruses may be a hitherto underappreciated cause of a post-infectious arthritis.

Dynamics of crowing development in the domestic Japanese quail (Coturnix coturnix japonica)

Species-specific behaviours gradually emerge, via incomplete patterns, to the final complete adult form. A classical example is birdsong, a learned behaviour ideally suited for studying the neural and molecular substrates of vocal learning. Young songbirds gradually transform primitive unstructured vocalizations (subsong, akin to human babbling) into complex, stereotyped sequences of syllables that constitute adult song. In comparison with birdsong, territorial and mating calls of vocal non-learner species are thought to exhibit little change during development. We revisited this issue using the crowing behaviour of domestic Japanese quail (Coturnix coturnix japonica). Crowing activity was continuously recorded in young males maintained in social isolation from the age of three weeks to four months. We observed developmental changes in crow structure, both the temporal and the spectral levels. Speed and trajectories of these developmental changes exhibited an unexpected high inter-individual variability. Mechanisms used by quails to transform sounds during ontogeny resemble those described in oscines during the sensorimotor phase of song learning. Studies on vocal non-learners could shed light on the specificity and evolution of vocal learning.

Good response to IL-1beta blockade by anakinra in a 23-year-old CINCA/NOMID patient without mutations in the CIAS1 gene. Cytokine profiles and functional studies

Chronic infantile neurological cutaneous and articular (CINCA) syndrome is an autoinflammatory disease, defined by the triad of urticarial rash, neurological manifestations, and arthropathy, accompanied by recurrent fevers and systemic inflammation. Increasing neurological deficits result from aseptic meningitis. Sensorineural hearing loss and progressive loss of vision caused by keratoconjunctivitis or papilloedema may emerge. An autosomal-dominant inheritance is suspected although sporadic cases are reported frequently. Sixty per cent of CINCA patients carry mutations in the cold-induced autoinflammatory syndrome (CIAS1) gene. We report the favourable response of a 23-year-old CINCA patient without CIAS1 mutations to treatment with the recombinant interleukin-1 (IL-1) receptor antagonist anakinra.

Bi-directional sexual dimorphisms of the song control nucleus HVC in a songbird with unison song

Sexually dimorphic anatomy of brain areas is thought to be causally linked to sex differences in behaviour and cognitive functions. The sex with the regional size advantage (male or female) differs between brain areas and species. Among adult songbirds, males have larger brain areas such as the HVC (proper name) and RA (robust nucleus of the arcopallium) that control the production of learned songs. Forest weavers (Ploceus bicolor) mated pairs sing a unison duet in which male and female mates learn to produce identical songs. We show with histological techniques that the volume and neuron numbers of HVC and RA were ≥1.5 times larger in males than in females despite their identical songs. In contrast, using in-situ hybridizations, females have much higher (30–70%) expression levels of mRNA of a number of synapse-related proteins in HVC and/or RA than their male counterparts. Male-typical and female-typical sexual differentiation appears to act on different aspects of the phenotypes within the same brain areas, leading females and males to produce the same behaviour using different cellular mechanisms.

[Osteoid osteomas of the fingers: an atypical localization? Two case reports and a review of the literature]

Osteoid osteomas are painful bone tumors that usually occur in childhood or adolescence. Despite the small size of the bony lesions osteoid osteomas can cause persistent pain. Pathogenesis has not been completely understood. Remission usually occurs within several months to years. Therefore surgical therapy is not indicated in all cases. Nevertheless, as a result of reduced quality of life due to pain, sufficient analgesic/antiinflammatory therapy needs to be provided. We report on two male patients, aged 10 and 14 years, who presented with arthritis of the finger joints. As a result of both patients' histories, and following radiographic imaging and magnetic resonance imaging, a diagnosis of osteoid osteoma was made. Remission could be achieved in both patients following treatment with nonsteroidal antiinflammatory drugs (NSAIDs).In addition to the typical sites at the long bones of the lower extremity, osteoid osteomas can also localize to other sites such as fingers. In the case of definitive diagnosis and under close follow-up, medical treatment with NSAIDs is an alternative to surgical strategies. The operative risk should be weighed against the risk of long-term treatment with NSAIDs.

Socially induced brain differentiation in a cooperatively breeding songbird

Birds living in social groups establish dominance hierarchies, and taking up the dominant position influences behaviour and physiological parameters. In cooperatively breeding white-browed sparrow weavers (Plocepasser mahali), the transition from subordinate helper to dominant breeder male induces the production of a new type of song. This song contains a large number of new syllables and differs in temporal pattern from duet songs produced by all other group members. Here we show that this change in social status of adult males affects the morphology of a behavioural control circuit, the song control system of songbirds that is composed of large neuron populations. The volume of the song control areas HVC and RA and their gene-expression levels depend on males' social status. Dominant males have several times larger testes than subordinates, which is not reflected in circulating androgen and oestrogen levels. Our findings suggest a remarkable differentiation of adult vertebrate brains in relation to changing social cues.

[Wegener's granulomatosis in pediatric patients]

Wegener's Granulomatosis (WG) is a disease occurring rarely in childhood and adolescence. Together with the Churg-Strauss-Syndrome and the microscopic Polyangiitis it belongs to the vasculitis syndromes associated with ANCA. WG mostly affects the upper and lower respiratory tract and kidneys. It is characterized by a chronic development and high tendency to relapse. In cases of persistent disturbances of the respiratory system which do not have infectious or allergic geneses differential diagnosis should also consider WG. Although clinical course and prognosis have improved since the introduction of immunosuppressive therapy, WG, leading to renal failure in about one third of all cases, remains a disease which has to be taken seriously. Early treatment has been proven to improve prognosis. Due to the necessity of longterm treatment less toxic immunosuppressive therapy should be applied (e.g. Methotrexate).

Mutations in the gene encoding the 3'-5' DNA exonuclease TREX1 are associated with systemic lupus erythematosus

TREX1 acts in concert with the SET complex in granzyme A-mediated apoptosis, and mutations in TREX1 cause Aicardi-Goutières syndrome and familial chilblain lupus. Here, we report monoallelic frameshift or missense mutations and one 3' UTR variant of TREX1 present in 9/417 individuals with systemic lupus erythematosus but absent in 1,712 controls (P = 4.1 x 10(-7)). We demonstrate that two mutant TREX1 alleles alter subcellular targeting. Our findings implicate TREX1 in the pathogenesis of SLE.

A mutation in TREX1 that impairs susceptibility to granzyme A-mediated cell death underlies familial chilblain lupus

We recently described a novel autosomal-dominant genodermatosis, termed familial chilblain lupus, and mapped its genetic locus to chromosome 3p21. Familial chilblain lupus manifests in early childhood with ulcerating acral skin lesions and is associated with arthralgias and circulating antinuclear antibodies. In this study, we report the identification of a heterozygous missense mutation (D18N) in TREX1 encoding the 3'-5'repair exonuclease 1 in affected individuals of the family with chilblain lupus. The homodimeric TREX1 is the most abundant intracellular DNase in mammalian cells. We have recently shown that TREX1 plays a role in apoptotic single-stranded DNA damage induced by the killer lymphocyte protease granzyme A. D18N affects a highly conserved amino acid residue critical for catalytic activity. Recombinant mutant TREX1 homodimers are enzymatically inactive, while wild type/mutant heterodimers show residual exonucleolytic activity, suggesting a heterozygous loss of function. Lymphoblastoid cells carrying the D18N mutation are significantly less sensitive to granzyme A-mediated cell death, suggesting a novel role for this caspase-independent form of apoptosis in the pathogenesis of familial chilblain lupus. Our findings also warrant further investigation of TREX1 in common forms of lupus erythematosus.

Spatial ability is impaired and hippocampal mineralocorticoid receptor mRNA expression reduced in zebra finches (Taeniopygia guttata) selected for acute high corticosterone response to stress

In mammals, stress hormones have profound influences on spatial learning and memory. Here, we investigated whether glucocorticoids influence cognitive abilities in birds by testing a line of zebra finches selectively bred to respond to an acute stressor with high plasma corticosterone (CORT) levels. Cognitive performance was assessed by spatial and visual one-trial associative memory tasks. Task performance in the high CORT birds was compared with that of the random-bred birds from a control breeding line. The birds selected for high CORT in response to an acute stressor performed less well than the controls in the spatial task, but there were no significant differences between the lines in performance during the visual task. The birds from the two lines did not differ in their plasma CORT levels immediately after the performance of the memory tasks; nevertheless, there were significant differences in peak plasma CORT between the lines. The high CORT birds also had significantly lower mineralocorticoid receptor mRNA expression in the hippocampus than the control birds. There was no measurable difference between the lines in glucocorticoid receptor mRNA density in either the hippocampus or the paraventricular nucleus. Together, these findings provide evidence to suggest that stress hormones have important regulatory roles in avian spatial cognition.

Early condition, song learning, and the volume of song brain nuclei in the zebra finch (Taeniopygia guttata)

Songbirds are an important model system for the study of the neurological bases of song learning, but variation in song learning accuracy and adult song complexity remains poorly understood. Current models of sexual selection predict that signals such as song must be costly to develop or maintain to constitute honest indicators of male quality. It has been proposed that reductions of nestling condition during song development might limit the expression of song learning. Adult song could thus act as an indicator of early stress as only males that enjoy good condition during development could learn accurately and sing long songs or large repertoires. We tested this hypothesis in the zebra finch by modifying early condition through cross-fostering chicks to small, medium, and large broods. Song learning was very accurate and was found to reflect very closely tutor song characteristics and to depend on the number of males in the tutoring group. Although the brood size manipulation strongly affected several measures of nestling condition and adult biometry, we found no relationship between early condition and song learning scores or song characteristics. Similarly, brain mass and high vocal center (HVC), robust nucleus of the arcopallium (RA), and lateral magnocellular nucleus of the anterior nidopallium (LMAN) volumes did not covary with nestling condition and growth measurements. We found no significant relationship between song repertoire size and HVC and RA volumes, although there was a nonsignificant trend for HVC to increase with increasing proportion of learnt elements in a song. In conclusion, the results provide no evidence for song learning to be limited by nestling condition during the period of nutritional dependence from the parents in this species.

Sexual Differentiation of the Vocal Control System of Birds

Birds evolved neural circuits of various complexities in relation to their capacity to produce learned or unlearned vocalizations. These vocalizations, in particular those that function in the realm of reproduction, are frequently sexually dimorphic, both in vocal learners (songbirds, parrots, some hummingbirds) and vocal nonlearners (all other birds). In many cases, the development and/or the adult differentiation of vocalizations of sociosexual function is sensitive to sex hormones, androgens and estrogens. The underlying mechanisms have been studied in detail in songbirds, a bird group that comprises about half of all bird species. Next to unlearned calls, songbirds produce learned songs that require forebrain vocal control areas that express receptors for androgens and estrogens. These forebrain vocal areas are sexually dimorphic in many species, but a clear relation between the degree of "brain sex" and sex differences in vocal pattern is lacking, except that a minimum number of vocal neurons is necessary to sing learned songs. Genetic brain-intrinsic mechanisms are likely to determine the neuron pools that develop into forebrain song control areas. Subsequently, gonadal steroid hormones, androgens and estrogens, modulate the fate of these neurons and thus the functionality of the vocal control systems. Further action of gonadal hormones, and may be other factors signaling the sociosexual and physical environment, affect the phenotype of vocal control areas in adulthood. Despite the clear evidence of hormone dependency of both adult vocalizations and phenotypes of vocal neuron pools, their causal relation is little understood.

Systemischer Lupus erythematodes im Kindes- und Jugendalter

Children and adolescents represent 15-20% of all systemic lupus erythematosus (SLE) patients. Although the clinical presentation and immunological findings are similar to those of adult SLE, children usually have a more severe disease at onset with higher rates of organ involvement. Rapid diagnosis and subsequent therapy are necessary to prevent major organ damage. The survival of children with SLE has improved dramatically over the past decades due to the introduction of steroids and immunosuppressive drugs. New strategies to improve the long-term course of the disease and to reduce potential drug toxicities are necessary. A common concept does not exist. There are some promising new drugs. This review article summarizes the epidemiology, pathogenesis, clinical manifestations and therapy of childhood and adolescent-onset SLE.

Familial chilblain lupus, a monogenic form of cutaneous lupus erythematosus, maps to chromosome 3p

Systemic lupus erythematosus is a prototypic autoimmune disease. Apart from rare monogenic deficiencies of complement factors, where lupuslike disease may occur in association with other autoimmune diseases or high susceptibility to bacterial infections, its etiology is multifactorial in nature. Cutaneous findings are a hallmark of the disease and manifest either alone or in association with internal-organ disease. We describe a novel genodermatosis characterized by painful bluish-red inflammatory papular or nodular lesions in acral locations such as fingers, toes, nose, cheeks, and ears. The lesions sometimes appear plaquelike and tend to ulcerate. Manifestation usually begins in early childhood and is precipitated by cold and wet exposure. Apart from arthralgias, there is no evidence for internal-organ disease or an increased susceptibility to infection. Histological findings include a deep inflammatory infiltrate with perivascular distribution and granular deposits of immunoglobulins and complement along the basement membrane. Some affected individuals show antinuclear antibodies or immune complex formation, whereas cryoglobulins or cold agglutinins are absent. Thus, the findings are consistent with chilblain lupus, a rare form of cutaneous lupus erythematosus. Investigation of a large German kindred with 18 affected members suggests a highly penetrant trait with autosomal dominant inheritance. By single-nucleotide-polymorphism-based genomewide linkage analysis, the locus was mapped to chromosome 3p. Haplotype analysis defined the locus to a 13.8-cM interval with a LOD score of 5.04. This is the first description of a monogenic form of cutaneous lupus erythematosus. Identification of the gene responsible for familial chilblain lupus may shed light on the pathogenesis of common forms of connective-tissue disease such as systemic lupus erythematosus.

Neural mechanisms of birdsong memory

The process through which young male songbirds learn the characteristics of the songs of an adult male of their own species has strong similarities with speech acquisition in human infants. Both involve two phases: a period of auditory memorization followed by a period during which the individual develops its own vocalizations. The avian 'song system', a network of brain nuclei, is the probable neural substrate for the second phase of sensorimotor learning. By contrast, the neural representation of song memory acquired in the first phase is localized outside the song system, in different regions of the avian equivalent of the human auditory association cortex.

A splice-supporting intronic mutation in the last bp position of a cryptic exon within intron 6 of the CYBB gene induces its incorporation into the mRNA causing chronic granulomatous disease (CGD)

Chronic granulomatous disease (CGD) is caused by a defect in both the host's defenses and its regulation of inflammation normally provided by phagocytes and other leukocytes. As in the case described here, it is not uncommon that CGD patients are diagnosed late, only after organ-damaging manifestations have already progressed. In this patient, we found that CGD arose due to a splice-supporting mutation in the last position of a cryptic exon towards the middle of intron 6 of the CYBB (gp91-phox) gene. The mutation led to the insertion of 56 bp into most of the CYBB mRNA of leukocytes causing a frame shift and a premature stop codon. The normal cryptic exon was also found to be mildly active in some tissues other than leukocytes in healthy donors, to be conserved in many primates, and to a lesser degree in other mammals. Some sequence similarity suggests that the cryptic exon may have originated from a mammalian interspersed repetitive (MIR) element. Taken together, we clarify an unusual disease-causing mutation, indicate its evolutionary background and emphasize the importance of a timely diagnosis of CGD.

Hormonal influence on song structure and organization: The role of estrogen

The development of song in songbirds is a complex phenomenon that involves memory and learning, sensorimotor integration, and neural and muscular maturation. Gonadal hormones are involved in each of these steps, as they influence the differentiation of the neural song system, the incorporation and survival of neurones, and the development of muscles used for song production. In young males the development of song, therefore, is closely linked to the secretion of testosterone by the testicles. Castration results in the development of incomplete or unstable songs, and hormone replacement leads to the development of crystallized or stable song. However, testosterone does not act solely as an androgen. The brain of songbirds contains high concentrations of the enzyme aromatase, which converts testosterone into estradiol. Estradiol then binds to estrogen receptors, which in the song system are found only in the nucleus HVC. This forebrain nucleus, also called the "master nucleus," codes for the syntactic structure of song, i.e. for the particular combination of simple elements-syllables-that characterize the song of an individual. In this paper, we will review our studies on the role of estrogen in guiding the organization of song in canaries.

P-glycoprotein expression increases ATP release in respiratory cystic fibrosis cells

P-glycoprotein (Pgp) is a well-defined ATP-binding cassette (ABC) protein and a close relative of cystic fibrosis transmembrane conductance regulator (CFTR), whose dysfunction causes cystic fibrosis (CF). It is postulated that Pgp can complement deficient CFTR functions because of structural and functional homologies. One of the most relevant functions appears to be the regulation of ATP release, which influences mucociliary clearance in respiratory epithelia by nucleotide receptor stimulation. However, mechanisms involved in ATP secretion remain a controversial issue. In the present study, CF epithelial cells (sigmaCFTE29ó) were transduced with the retroviral vector MP1m encoding Pgp, and thus, a stable Pgp-overexpressing CF cell line (sigmaCFTE29óPgp) was established and used for studies of hypothesized CFTR complementation. In addition, overexpression of native Pgp in sigmaCFTE29ó could also be achieved by long-term treatment with colchicine, a drug, which may be of great interest in CF therapy. We confirmed that overexpression of Pgp causes a significant increase in cellular ATP release, which could even be enhanced by stimulation with hypoosmolar medium. A potential clinical benefit is discussed.

Benefit assessment of preventive medical check-ups in patients suffering from chronic granulomatous disease (CGD)

BACKGROUND

Chronic granulomatous disease (CGD) patients are susceptible to recurrent opportunistic infections and to recurrent or chronic inflammations of presumably non-infectious origin. Both types of manifestations are often accompanied by granuloma formation. Both can remain unnoticed until they deteriorate considerably and can become life-threatening if not treated in time.

OBJECTIVE

To evaluate the effectiveness of regular follow-up visits in CGD patients.

METHODS

Findings of imaging (ultrasound, radiographs, computer-tomography, magnetic resonance imaging), lung function tests, histopathological and microbiological assessments of biopsies have been reviewed.

RESULTS

A total of 32 CGD patients have been evaluated within 15 years. Of these eight patients have been checked regularly for more than 5 years. Early detection prior to specific clinical signs and consecutive treatment of six lung manifestations and one liver manifestation such as interstitial pneumonia with formation of small granulomas, formation of large granulomas, fibrosis, Aspergillus infections, and abscesses could presumably prevent considerable aggravation in seemingly healthy or mildly symptomatic patients. In contrast, patients without surveillance who presented with severe symptoms (seven manifestations) often had irreversible organ damage or even died.

CONCLUSIONS

Regular follow-up visits can help prevent or mitigate clinical manifestations, improve life quality and expectancy and weigh indication for bone marrow transplantation in CGD patients.

Influence of CARD15 mutations on disease activity and response to therapy in 65 pediatric Crohn patients from Saxony, Germany

OBJECTIVES

Certain genetic variants in the CARD15 gene are accompanied by an enhanced risk to develop Crohn disease with the main activity in the terminal ileum and ensuing stricturing early in life. The objective of this study was to evaluate the relation between CARD15 mutations and overall disease activity and response to therapy in pediatric patients.

METHODS

65 genomic DNA samples from such patients were tested for the presence of three main Crohn associated mutations in CARD15 by direct genomic sequencing. The number of mutations (none, one or two alleles affected) was correlated with body mass index and height, Pediatric Crohn Disease Activity Index, therapy and therapeutical success in terms of body mass index and Pediatric Crohn Disease Activity Index improvement.

RESULTS

The authors found a nonsignificant trend of a lower body mass index and higher Pediatric Crohn Disease Activity Index in patients with CARD15 mutations. Physicians uninformed about their CARD15 status prescribed significantly more budesonide and prednisolone intermittently and more alimentary supplementation to these patients. The average improvement in terms of body mass index and Pediatric Crohn Disease Activity Index after 2 years of therapy was roughly similar in all patient groups.

CONCLUSIONS

Pediatric Crohn patients with CARD15 mutations have a higher disease activity and need a more intensive therapy. With some exceptions, their medium-term response to therapy is nevertheless satisfying.

Haploinsufficiency, rather than the effect of an excessive production of soluble CD95 (CD95{Delta}TM), is the basis for ALPS Ia in a family with duplicated 3' splice site AG in CD95 intron 5 on one allele

Autoimmune lymphoproliferative syndrome type Ia (ALPS Ia) is caused by mutations in the CD95/APO1/FAS (TN-FRSF6) gene, which lead to a defective CD95 ligand (CD95L)-induced apoptosis. Soluble CD95 (sCD95) has been suggested to play an important role in the pathogenesis of diverse autoimmune and malignant diseases by antagonizing CD95L. Here we evaluate a family with 4 of its 5 members harboring an ex-6-3C-->G mutation that affects the splice cis regulatory region (cctacag/ex-6-->cctagag/ex-6) of the CD95 gene. The mutation causes skipping of exon-6, which encodes the transmembrane region of CD95, and thereby leads to an excessive production of sCD95 in all 4 affected individuals. The mutation is associated with a low penetrance of disease phenotype and caused mild and transient ALPS in one male patient whereas all other family members are completely healthy. In all family members with the mutation we found that the cell surface expression of CD95 was low and the activated T cells were resistant to CD95-induced apoptosis. Unexpectedly, excessive production or addition of sCD95 had no effect on the CD95-induced apoptosis in diverse cells. In contrast, increasing the surface expression of CD95 was able to correct the defect in apoptosis. Thus we conclude that the ALPS in the one male patient was caused by haploinsufficiency of membrane CD95 expression. Our data challenge the hypothesis that sCD95 causes autoimmunity.

Identification of novel GCK and HNF1A/TCF1 mutations and polymorphisms in German families with maturity-onset diabetes of the young (MODY)

Maturity-onset diabetes of the young is a genetically heterogeneous autosomal dominant form of diabetes mellitus, characterized by an early age at onset and a primary defect in beta-cell function. Forty families with a clinical presentation suggestive of MODY were screened for the most common MODY subtypes caused by mutations in the genes encoding glucokinase (GCK, MODY2) and hepatocyte nuclear 1-alpha (HNF1A/TCF1, MODY3). Overall, 14 mutations were found (35%) giving a relative frequency of 22.5% and 12.5% for MODY2 and MODY3, respectively. Five of the nine GCK mutations identified were novel and included two deletions, two nonsense, and one splice site mutation. The GCK splice donor mutation was shown to result in an aberrant transcript owing to the recruitment of a cryptic splice site. The translated protein is predicted to contain an in frame insertion of nine amino acids. Among the five HNF1A mutations identified, three were novel comprising one missense mutation, one deletion, and one insertion. In addition, several novel polymorphisms within GCK were identified and their allele frequencies estimated. Knowledge of the genetic cause of MODY has significant impact on therapeutic decision making and may help to identify family members at risk for diabetes.