Two imprinted gene mutations: three phenotypes

Genetic modifications of imprinted genes have been generated in the mouse to investigate the regulation of their expression. They show classical imprinted gene inheritances. Here we describe two imprinted gene mutations deriving from mutagenesis experiments. One is expressed only when transmitted through males. It causes a prenatal growth retardation which resembles that of the Igf2 knockout and maps close to the locus on chromosome 7. Differences from the knockout, which include an abnormal head phenotype, homozygous lethality, and an inability to rescue a TME: (Igf2r-deficient) lethality, suggest that Igf2 itself may not be directly affected. The second mutation maps close to the GNAS: cluster of imprinted genes on distal chromosome 2. It gives two distinct phenotypes according to parental origin, a gross neonatal oedema with microcardia and a postnatal growth retardation. The oedema phenotype is effectively lethal and resembles that of mice with paternal partial disomy for distal chromosome 2, as well as that of mice having a maternally derived GNAS: exon 2 knockout. However, the second growth retardation phenotype differs from that of the maternal partial disomy and the paternal knockout. A hypothesis to explain the phenotypes associated with the three genotypes based on the NESP:/NESPAS: sense/antisense and GNASXL: transcripts in the GNAS: cluster is offered.

Elevated levels of lipoprotein(a) in familial bone marrow edema syndrome of the hip

There is controversy whether bone marrow edema syndrome represents a distinct transient disease or reflects an early reversible phase of spontaneous osteonecrosis of the hip. Hypofibrinolysis on the basis of elevated plasma levels of plasminogen activator inhibitor or lipoprotein(a) or both has been reported to favor the development of bone marrow edema syndrome and nontraumatic avascular necrosis. The current authors report on the familial occurrence of transient bone marrow edema syndrome of the hip in three female family members. Plasma concentrations of lipoprotein(a) were elevated in all three patients, whereas serum levels of plasminogen activator inhibitor were within normal ranges. This first familial description of transient bone marrow edema syndrome of the hip strongly suggests that a genetically determined elevation of lipoprotein(a) may be an important predisposing factor in these patients.

Fatal bilateral chylothorax in mice lacking the integrin alpha9beta1

Members of the integrin family of adhesion receptors mediate both cell-cell and cell-matrix interactions and have been shown to play vital roles in embryonic development, wound healing, metastasis, and other biological processes. The integrin alpha9beta1 is a receptor for the extracellular matrix proteins osteopontin and tenacsin C and the cell surface immunoglobulin vascular cell adhesion molecule-1. This receptor is widely expressed in smooth muscle, hepatocytes, and some epithelia. To examine the in vivo function of alpha9beta1, we have generated mice lacking expression of the alpha9 subunit. Mice homozygous for a null mutation in the alpha9 subunit gene appear normal at birth but develop respiratory failure and die between 6 and 12 days of age. The respiratory failure is caused by an accumulation of large volumes of pleural fluid which is rich in triglyceride, cholesterol, and lymphocytes. alpha9(-/-) mice also develop edema and lymphocytic infiltration in the chest wall that appears to originate around lymphatics. alpha9 protein is transiently expressed in the developing thoracic duct at embryonic day 14, but expression is rapidly lost during later stages of development. Our results suggest that the alpha9 integrin is required for the normal development of the lymphatic system, including the thoracic duct, and that alpha9 deficiency could be one cause of congenital chylothorax.

A clinical, cytogenetic and molecular study of 47 females with r(X) chromosomes

We studied 47 patients with a 45,X/46,X,r(X) karyotype to identify phenotypic differences between these patients and 45,X patients, and to determine whether these differences could be explained by the status of genes within the ring. Only 2 patients had the 'severe' r(X) phenotype, and both were consistent with this resulting from functional disomy of genes normally subject to X inactivation. A further 7 patients also carried active rings but these patients did not have a more severe phenotype than those whose rings were inactivated, probably because their rings were smaller and did not contain the (as yet unidentified) genes whose functional disomy is particularly damaging. Patients with a r(X) did not show clear physical differences when compared with a 45,X series, except for a possible reduction in the frequency of oedema in those whose r(X) had an Xq breakpoint distal to DXS128E, at Xq13.2. Thus some protection from oedema may be provided by the presence of two copies of Xq13.2.

Transcription-coupled and global genome repair differentially influence UV-B-induced acute skin effects and systemic immunosuppression

Exposure to UV-B radiation impairs immune responses in mammals by inhibiting especially Th1-mediated contact hypersensitivity and delayed-type hypersensitivity. Immunomodulation is not restricted to the exposed skin, but is also observed at distant sites, indicating the existence of mediating factors such as products from exposed skin cells or photoactivated factors present in the superficial layers. DNA damage appears to play a key role, because enhanced nucleotide excision repair (NER) strongly counteracts immunosuppression. To determine the effects of the type and genomic location of UV-induced DNA damage on immunosuppression and acute skin reactions (edema and erythema) four congenic mouse strains carrying different defects in NER were compared: CSB and XPC mice lacking transcription-coupled or global genome NER, respectively, as well as XPA and TTD/XPD mice carrying complete or partial defects in both NER subpathways, respectively. The major conclusions are that 1) transcription-coupled DNA repair is the dominant determinant in protection against acute skin effects; 2) systemic immunomodulation is only affected when both NER subpathways are compromised; and 3) sunburn is not related to UV-B-induced immunosuppression.

Genetic factors determine the contribution of leukotrienes to acute inflammatory responses

Leukotrienes (LT) are potent lipid mediators synthesized by the 5-lipoxygenase pathway of arachidonic acid (AA) metabolism. LT have been implicated in a broad spectrum of inflammatory processes. To investigate the influence of genetic factors on the contribution of LT to acute inflammation, we generated congenic 5-lipoxygenase-deficient 129, C57BL/6 (B6), and DBA/1Lac (DBA) mouse lines. Topical application of AA evoked a vigorous inflammatory response in 129 and DBA mice, whereas only a modest response was seen in B6 animals. The response to AA in 129 and DBA strains is LT dependent. In contrast, LT make little contribution to this response in B6 mice. AA-induced inflammation in B6 mice is prostanoid dependent, since this response was substantially reduced by treating B6 mice with a cyclooxygenase inhibitor. These data suggest that prostanoids are essential for AA-induced cutaneous inflammation in B6 mice, whereas LT are the major mediators of this response in 129 and DBA strains. In contrast, the response to AA in the peritoneal cavity is robust in the 129 and B6 strains, but was significantly blunted in DBA mice, showing that strain differences in the response to AA are tissue specific. Variations in these and other experimental models of inflammation appear to correlate directly with the ability of a particular mouse strain and a specific tissue to respond to LT, specifically LTC4. Taken together, these findings indicate that the relative contribution of prostanoids and LT to inflammatory responses is variable not only between strains but also between different tissues within these inbred mouse lines.

Deletion of crhr2 reveals an anxiolytic role for corticotropin-releasing hormone receptor-2

Corticotropin-releasing hormone (Crh), a 41-residue polypeptide, activates two G-protein-coupled receptors, Crhr1 and Crhr2, causing (among other transductional events) phosphorylation of the transcription factor Creb. The physiologic role of these receptors is only partially understood. Here we report that male, but not female, Crhr2-deficient mice exhibit enhanced anxious behaviour in several tests of anxiety in contrast to mice lacking Crhr1. The enhanced anxiety of Crhr2-deficient mice is not due to changes in hypothalamic-pituitary-adrenal (HPA) axis activity, but rather reflects impaired responses in specific brain regions involved in emotional and autonomic function, as monitored by a reduction of Creb phosphorylation in male, but not female, Crhr2-/- mice. We propose that Crhr2 predominantly mediates a central anxiolytic response, opposing the general anxiogenic effect of Crh mediated by Crhr1. Neither male nor female Crhr2-deficient mice show alterations of baseline feeding behaviour. Both respond with increased edema formation in response to thermal exposure, however, indicating that in contrast to its central role in anxiety, the peripheral role of Crhr2 in vascular permeability is independent of gender.

[Significance of nuchal edema in fetuses of pregnant women under 35 years of age]

The aim of this study was to survey the connection between the fetal nuchal oedema and the increased risk of the aneuploidies. According to the prenatal care the thickness of the nuchal fold was measured on the 11-12th gestational week by 6.5 MHz transvaginal transducer (ATL-HDI and Hitachi EUB-450). Cases were underlined where the presence of nuchal oedema (> or = 3 mm) made the indication for chromosomal analysis among the 280 single pregnancies and fetal karyotyping was carried out. Nuchal oedema was observed in 72/280 cases of pregnant women under 35 years old and in 20/280 cases of that above 35 years old, the nuchal oedema was another indication beside the age. Abnormal karyotype was observed in 9/72 (12.5%) cases among the pregnant women under 35 years old and in 10/92 (10.87%) cases among the pregnancies with fetal nuchal oedema. It was also observed abnormal karyotype in 6/188 (3.19%) cases of pregnancies without nuchal oedema and in 16/280 (5.71%) cases of chromosomal analyses with or without nuchal oedema. This can be an effective method for screening the fetal aneuploidies and other fetal anomalies, both in the high risk and the normal pregnant population, especially in cases of pregnant women under 35 years old belonging to the normal genetical risk population.

Identification of supernumerary marker chromosomes derived from chromosomes 5, 6, 19, and 20 using FISH

A large number of cases with supernumerary marker chromosomes (SMCs) should be compared to achieve a better delineation of karyotype-phenotype correlations. Here we present four phenotypically abnormal patients with autosomal marker chromosomes analysed by fluorescence in situ hybridisation using centromeric, telomeric, and unique sequence probes, as well as forward and reverse painting. We also report the first case, to the best of our knowledge, of an SMC derived from chromosome 5. Furthermore, a marker chromosome 20 in a patient with sex differentiation abnormalities, a double mar(6) in a boy with psychomotor retardation, and the association of r(19) with dup(21q21.2q22.12) are described. Although the mar(6) was very small, the presence of euchromatin was shown, suggesting that the partial trisomy of pericentric region derived sequences is implicated in the aetiology of the abnormal phenotypes.

Imprinting of distal mouse chromosome 2 is associated with phenotypic anomalies in utero

Previous studies have shown that the distal region on mouse chromosome (Chr) 2 is subject to imprinting as mice with maternal duplication/paternal deficiency (MatDp.dist2) and the reciprocal (PatDp.dist2) for this region exhibit phenotypic anomalies at birth and die neonatally. We show here that imprinting effects are detectable in utero. Notably PatDp.dist2 embryos show an increase in wet weight compared with normal, which peaks at 16.5 d post coitum (dpc), and diminishes by birth, whereas the wet weight of placenta is slightly reduced in the latter half of gestation. Newborns have increased length of the long bones. By contrast, the wet weight of MatDp.dist2 embryos decreases during the second half of gestation. Measurements of dry weights of embryos at 16.5 dpc have indicated that there is no difference in either PatDp.dist2 or MatDp.dist2 compared with normal so that the wet weight differences are due to fluid retention in PatDp.dist2 but fluid loss in MatDp.dist2. In PatDp.dist2 embryos excess fluid is particularly prominent in the subcuticular skin layer, whereas by birth fluid is evident around the neck and tongue. At 16.5 dpc the PatDp.dist2 embryos are severely oedematous, as the average fluid content per unit dry weight per embryo was increased by 40%, whereas the MatDp.dist2 embryos are dehydrated as the average water content per unit dry weight per embryo was reduced by 6%. A preliminary conclusion is that there is neither growth enhancement in PatDp.dist2 nor growth retardation in MatDp.dist2 offspring.

Nevo syndrome

We report on a patient with Nevo syndrome manifesting intrauterine and postpartum overgrowth, accelerated osseous maturation, dolichocephaly, highly arched palate, large, low-set ears, cryptorchidism, delayed neuropsychological development, hypotonia, adema, contractures of the hands and feet, a single a transverse palmar crease, and tapering digits. After meningococcal sepsis at age 6 months, he remained decerebrate. Thereafter, overgrowth and especially weight gain were extremely accelerated until his death at age 18 months, at which time his height was 103 cm and his weight was 23 kg. In addition to low plasma concentrations of growth hormone and insulin-like growth factor, severe insulin resistance was observed. It is presumed that a selective defect in insulin-stimulated glucose uptake, with preservation of anabolic effect, was one of the causes of his "overgrowth without growth hormone," at least in the last 12 months of life after severe brain damage.

Neutrophil emigration in the skin, lungs, and peritoneum: different requirements for CD11/CD18 revealed by CD18-deficient mice

To determine the role of CD11/CD18 complexes in neutrophil emigration, inflammation was induced in the skin, lungs, or peritoneum of mutant mice deficient in CD18 (CD18-/- mutants). Peripheral blood of CD18-/- mutants contained 11-fold more neutrophils than did blood of wild-type (WT) mice. During irritant dermatitis induced by topical application of croton oil, the number of emigrated neutrophils in histological sections of dermis was 98% less in CD18-/- mutants than in WT mice. During Streptococcus pneumoniae pneumonia, neutrophil emigration in CD18-/- mutants was not reduced. These data are consistent with expectations based on studies using blocking antibodies to inhibit CD11/CD18 complexes, and on observations of humans lacking CD11/CD18 complexes. The number of emigrated neutrophils in lung sections during Escherichia coli pneumonia, or in peritoneal lavage fluid after 4 h of S. pneumoniae peritonitis, was not reduced in CD18-/- mutants, but rather was greater than the WT values (240 +/- 30 and 220 +/- 30% WT, respectively). Also, there was no inhibition of neutrophil emigration during sterile peritonitis induced by intraperitoneal injection of thioglycollate (90 +/- 20% WT). These data contrast with expectations. Whereas CD11/CD18 complexes are essential to the dermal emigration of neutrophils during acute dermatitis, CD18-/- mutant mice demonstrate surprising alternative pathways for neutrophil emigration during pneumonia or peritonitis.

Genes specifying receptors for F18 fimbriated Escherichia coli, causing oedema disease and postweaning diarrhoea in pigs, map to chromosome 6

The study comprised 236 pigs selected for resistance or susceptibility to oedema disease. The susceptibility to colonization of the small intestine by an Escherichia coli strain causing oedema disease was determined: (1) by monitoring faecal excretion of weaned pigs orally inoculated with E. coli strain O139:K12(B):H1:F18ab serotype; and (2) by an in vitro adhesion assay using an F18ab positive E. coli strain and small intestinal enterocyte preparations. Susceptibility to adhesion by these bacteria was shown to be controlled by a dominant (B) allele of the ECF18R locus and resistance by the alternative recessive allele (b). Pigs were typed for 14 blood group systems, 11 biochemical polymorphisms and the polymorphism at nucleotide 1843 of the RYR1 locus. Linkage was demonstrated between the locus for F18 E. coli receptors and the loci S, RYR1, GPI, EAH, A1BG and PGD (Z > 20). The most likely gene orders are: S-ECF18R-RYR1-GPI-PGD or GPI-RYR1-ECF18R-S-PGD. The recombination frequencies between ECF18R-S and ECF18R-RYR1 were estimated to be theta = 0.5% and 3.1%, respectively.

Macula halo syndrome and non-pitting lid oedema in an Italian family

We report an undocumented association of macula halo syndrome and mechanical ptosis secondary to nonpitting oedema in two members of an Italian family. Macula halo syndrome is universally recognised to be variant of Niemann-Pick disease type B, a lipid storage disorder which is ultimately diagnosed by measuring sphingomyelinase activity levels. Although the diagnosis could not be confirmed because of our patients' refusal to undergo enzymatic investigation, the clinical picture proved to be highly compatible with the suggested diagnosis. We discuss the possible clinical differential diagnosis of lipid storage diseases involving the retina.

Expression of vascular permeability factor (VPF/VEGF) messenger RNA by plasma cells: possible involvement in the development of edema in chronic inflammation

Edema occurs in some types of chronic inflammation such as nasal polyps, uterine cervical polyps and gastric hyperplastic polyps. However, the factors or cellular components involved in the development of edema in chronic inflammation remain to be clarified. Recently, the gene encoding vascular permeability factor (VPF) or vascular endothelial growth factor (VEGF) and the genes encoding its receptors (kinase insert domain-containing receptor (KDR) and fms-like tyrosine kinase-1 [fit-1]) have been cloned. VPF/VEGF induces vascular hyperpermeability and vascular endothelial proliferation through KDR or fit-1 receptors. As there is a possibility that VPF/VEGF may play a role in the development of edema in chronic inflammation, we examined the messenger (m) RNA expression of VPF/VEGF and its receptors in nasal polyp tissues, which is an example of chronic inflammation with remarkable edema. Using northern blotting, all nasal polyp tissues examined expressed mRNA of VPF/VEGF and KDR. In situ hybridization revealed that VPF/VEGF mRNA-expressing cells were scattered in the edematous stroma of nasal polyps. In the adjacent sections, these cells showed the morphological features of plasma cells and expressed mRNA of immunoglobulin light chains. Human B cell leukemia and plasmacytoma cell lines expressed VPF/VEGF mRNA but human mast-cell leukemia and T cell leukemia cell lines did not. The alternatively spliced pattern of VPF/VEGF transcripts observed in nasal polyp tissues was consistent with that in plasmacytoma cell lines. Taken together, the VPF/VEGF mRNA-expressing cells in nasal polyps appeared to be plasma cells, suggesting that plasma cells may play an important role in the development of edema in chronic inflammation through the production of VPF/VEGF.

Familial enteropathy with villous edema and immunoglobulin G2 subclass deficiency

We describe a familial form of recurrent acute, life-threatening secretory diarrhea associated with distinctive jejunal histologic changes and IgG2 subclass deficiency. Symptoms begin abruptly with anorexia and vomiting, and progress within hours to massive secretory diarrhea and shock with profound neutropenia and hypoproteinemia, including hypoalbuminemia and hypogammaglobulinemia. Affected survivors recover quickly and thereafter grow and develop normally. Biopsy specimens obtained during remission from 3 adults and 11 children show club-shaped jejunal villi broadened by edema and histiocytes with imbibed fluid; the overlying intestinal epithelium and brush border appear normal, but the basement membrane is interrupted in some areas. No characteristic microorganisms have been identified in association with the syndrome. Clinical manifestations cease in the second decade, but the abnormal jejunal histologic pattern persists into adult life. Female and male patients are equally affected, although all fatal cases have been in female subjects. Inheritance appears dominant with variable penetrance: one family member without a history of diarrhea has characteristic biopsy findings and another appears to be an obligate carrier with normal biopsy findings. Affected individuals have a reduced serum concentration of IgG2. We believe that this familial enteropathy is a unique entity, not previously described.

First trimester diagnosis of fetal nuchal edema. Report of 29 cases

During a 4-year period, 29 fetal nuchal edemas were observed, associated with other ultrasound abnormalities in 7 cases (24%). Fetal karyotypes were abnormal in 10 cases: 6 trisomy 21; 3 trisomy 18, and 1 Turner's syndrome. Isolated fetal nuchal edema was associated with aneuploidy in 4 cases: 3 trisomy 21, and 1 trisomy 18. The average age of the women carrying a fetus with nuchal edema associated or not with a trisomy 21 was 38.3 and 30.8 years, respectively. These results are similar to those found in the literature. It would appear that maternal age is a better marker in trisomy 21 screening than isolated fetal nuchal edema.

Fetal nuchal oedema and antenatal diagnosis of trisomy 10

Trisomy 10 was detected at amniocentesis undertaken following observation of fetal nuchal oedema. This is the first report of fetal trisomy 10 in association with nuchal oedema. The physical features of fetal trisomy 10 are described.

Nitric oxide- and hydrogen peroxide-mediated gene expression by glucocorticoids and FK506 in histamine paw edema of mice

An immunosuppressant FK506 binds with a component (hsp 56) of glucocorticoid receptor (GR) complex. Dexamethasone (Dex) never suppressed histamine paw edema of mice before 1 hr after its dosing as new protein(s) synthesis is required. However, FK506 (0.01-10 mg/kg, oral) 1.5 hr before 0.1 mg/kg Dex (s.c.), suppressed edema at 30 min. This suppression and that at 3 hr, were abolished by nitric oxide (NO) synthesis inhibitors (1-300 mg/kg). Nitroprusside (NO donor), catalase and molybdate (GR complex stabilizing protease inhibitor) enhanced the suppression. FK506, not cyclosporin A, was demonstrated for the first time in vivo to enhance GR and a hypothesis is proposed that FK506 might enhance GR and AP-1 signalings in a system reciprocally controlled by NO and H2O2.

Familial cold urticaria--a rare cause of lip swelling

Cold urticaria is an unusual condition characterised by wealing of the skin or mucous membranes following exposure to cold. This report describes a presentation with recurrent lip swelling.

Diagnostic criteria and genetics of the PEHO syndrome

The PEHO syndrome (progressive encephalopathy with oedema, hypsarrhythmia, and optic atrophy) is a recently recognised disorder of unknown biochemical background. Diagnostic features have been found in neuroradiological and neuropathological studies, which show characteristic severe cerebellar atrophy. In combined neuroradiological and ophthalmological studies, 10 out of 21 possible PEHO patients fulfilled the criteria for true PEHO syndrome. All were abnormal at birth showing hypotonia, drowsiness, or poor feeding. Head circumference was normal, but usually dropped to 2 SD below average during the first year of life. Visual fixation was either absent from birth or lost during the first months of life. Nine patients had peripheral oedema in early childhood. The mean age of onset of infantile spasms was 4.9 months. All patients were extremely hypotonic and no motor milestones were reached. Patellar reflexes were brisk. Brain stem and somatosensory evoked potentials were abnormal in each case studied, cortical responses of somatosensory evoked potentials could not be elicited, and motor conduction velocities became delayed with age. Altogether 19 PEHO patients were found in 14 Finnish families. Autosomal recessive inheritance is likely.

Epilepsy and the electroencephalogram in progressive encephalopathy with edema, hypsarrhythmia, and optic atrophy (the PEHO syndrome)

Progressive encephalopathy with edema, hypsarrhythmia, and optic atrophy (PEHO) syndrome) is an apparently autosomal recessive disorder manifested by infantile spasms, severe hypotonia, and early arrest of psychomotor development. Subcutaneous edema in the limbs, typical facial features, and blindness with optic atrophy are also present. Neuropathologic and radiographic studies show progressive brain atrophy, which is accentuated infratentorially. We recorded 85 EEGs from 10 patients between the ages of 3 weeks and 12.7 years; follow-up ranged from 7 months to 12.1 years. The infantile spasms were preceded by other neurological symptoms in all patients. Seven of nine patients showed focal or generalized epileptiform activity or abnormal EEG background. All patients developed hypsarrhythmia, first recorded between 3 and 11 months of age, that was resistant to therapy with ACTH and antiepileptic drugs. After the hypsarrhythmia disappeared, five patients showed slow spike-wave activity generally seen in the Lennox-Gastaut syndrome, and three patients showed background EEG abnormality with generalized or diffuse paroxysmal activity. There were no specific EEG features that could help in the diagnosis of PEHO. The PEHO syndrome should be borne in mind in the diagnostic work-up of patients with infantile spasms, so that potentially harmful treatment can be avoided, and the parents can be counseled about the inheritability of the disorder.

Familial idiopathic oedema in prepubertal children: a new syndrome

Idiopathic oedema has not been previously described in prepubertal children. Between 1977 and 1991, eighteen children (15 girls, three boys) from 13 unrelated kindreds presented with the clinical features of idiopathic oedema commencing between the neonatal period and 12 years. These comprised a triad of swelling, affective disturbance and functional autonomic symptoms. There was a family history of idiopathic oedema in 16 (89%) children, including all 15 girls, and of diabetes mellitus in 12 (67%) children, suggesting a major genetic basis for the syndrome. Laboratory investigations excluded cardiovascular, hypoproteinaemic, allergic and obstructive causes of oedema. Adherence to a restricted carbohydrate diet, the avoidance of refined carbohydrate and the correction of precipitating weight gain controlled symptoms in most children. Relapses followed dietary non-compliance and life-event stress. A neurotransmitter-based autonomic abnormality of vascular and visceral smooth muscle tone modulated by metabolic and neuroendocrine mechanisms provides a partial explanation for this syndrome. Insulin-mediated modulation of capillary permeability to water and electrolytes may also be involved. The pathogenesis, clinical features and management of paediatric idiopathic oedema may provide a model for the adult syndrome.

A new ectrodactyly syndrome?

We report a fetus with hydrops, ectrodactyly, syndactyly, duplication of the great toes and several other features. From a review of the literature we suggest that this constellation of abnormalities has not previously been reported.