A management algorithm for congenital erythropoietic porphyria derived from a study of 29 cases

BACKGROUND

Congenital erythropoietic porphyria (CEP) is an autosomal recessive photomutilating porphyria with onset usually in childhood, where haematological complications determine prognosis. Due to its extreme rarity and clinical heterogeneity, management decisions in CEP are often difficult.

OBJECTIVES

To develop a management algorithm for patients with CEP based on data from carefully characterized historical cases.

METHODS

A single investigator collated data related to treatments and their outcomes in 29 patients with CEP from the U.K., France, Germany and Switzerland.

RESULTS

Six children were treated with bone marrow transplantation (BMT); five have remained symptomatically cured up to 11.5 years post-transplantation. Treatments such as oral charcoal, splenectomy and chronic hypertransfusion were either of no benefit or were associated with complications and negative impact on health-related quality of life. Lack of consistent genotype-phenotype correlation meant that this could not be used to predict disease prognosis. The main poor prognostic factors were early age of disease onset and severity of haematological manifestations.

CONCLUSIONS

A management algorithm is proposed where every patient, irrespective of disease severity at presentation, should receive a comprehensive, multidisciplinary clinical assessment and should then be reviewed at intervals based on their predicted prognosis, and the rate of onset of complications. A BMT should be considered in those with progressive, symptomatic haemolytic anaemia and/or thrombocytopenia. Uroporphyrinogen III synthase genotypes associated with poor prognosis would additionally justify consideration for a BMT. Rigorous photoprotection of the skin and eyes from visible light is essential in all patients.

Allogeneic bone marrow transplantation in a 7-year-old girl with congenital erythropoietic porphyria: a treatment dilemma

Congenital erythropoietic porphyria (CEP, Günther's disease) has a very variable phenotype. In the more severely affected, bone marrow transplantation (BMT) is potentially curative, but is not without risks. We describe a 7-year-old girl with CEP characterized by severe photosensitivity but only mild anaemia, in whom the difficult decision to proceed with allogeneic BMT was made after discussion in a multidisciplinary team. She has shown successful engraftment, accompanied by biochemical and clinical resolution of her metabolic disease. She remains well 3 years later, the oldest patient with CEP receiving BMT to survive beyond 12 months. However, she has experienced significant morbidity including florid cutaneous graft-versus-host disease with postinflammatory hypopigmentation. Her case is important in highlighting the delay in diagnosis not uncommon in this condition and the complex decision-making process involved in proceeding with BMT.

A randomised comparison of the effect of three patient information leaflet models on older patients' treatment intentions

One hundred and ninety-six patients over the age of 65 years suffering from joint pain were randomised to receive one of three patient information leaflets describing a hypothetical pain medication, a standard textual patient information leaflet (PIL) given out by a pharmaceutical chain, and two alternate-forms depicting information with icons and graphs. The results showed that patients randomised to the traditional PIL were less likely to consider taking the hypothetical medication.

Androgen-controlled specific gene expression in neuroblastoma cells

In Kennedy's syndrome, a mutation in the androgen receptor (AR) gene leads to sensory and lower motor neurone degeneration, therefore genes that are regulated by androgens in neurones may be important in the process of motor neurone cell death. The aim of this study was to identify androgen-inducible genes in the human neuroblastoma cell line SH-SY5Y. We have shown that SH-SY5Y cells expressed the AR by Northern blot analysis using a 32P-labelled probe derived from a human AR cDNA. Differential display of mRNAs has been used to identify and clone putative genes that are regulated by androgens in SH-SY5Y cells. Nine cDNA fragments, ranging in size from 180 bp to 480 bp, corresponding to mRNA species which appear to be differentially expressed in response to 5 alpha dihydrotestosterone (DHT), have been successfully cloned. These are now being sequenced and used as hybridisation probes for Northern blot analysis in order to confirm their induction by DHT. Characterisation of these genes may provide clues to the mechanisms of motor neurone degeneration.

The lymphoblast beta-adrenergic receptor in bipolar depressed patients: effect of chronic incubation with lithium chloride

We have recently reported a study of beta-adrenergic receptor binding characteristics in lymphoblast cell lines derived from patients with bipolar disorder (BD) and healthy, matched control subjects. In the present study we have investigated the effects of incubating cells from the same subjects with lithium chloride (1 mM) for 7 days prior to assay. There was no difference in beta-adrenergic receptor number between control and BD cell lines and incubation with lithium had no effect on receptor number in either group. Exposure of the cells to isoprenaline (1 nM) for 24 h immediately prior to assay caused significantly less down-regulation in BD cells (15 +/- 5%) than control cells (39 +/- 4%), as described previously. Incubation with lithium significantly increased the down-regulation response to isoprenaline in BD cells (39 +/- 6%) but not in control cells (30 +/- 7%). After lithium, the agonist-induced decrease in beta-AR number in BD cells was no longer significantly different from that in control cells. We conclude that lithium selectively enhanced the agonist down-regulation of beta-adrenergic receptors in cells derived from patients with bipolar disorder. The functional significance of this result and the potential biochemical mechanisms responsible for this effect are discussed.

Failure to find linkage between schizophrenia and genetic markers on chromosome 21

We sought evidence for the involvement of mutations in the amyloid precursor protein gene (APP) in the pathogenesis of schizophrenia in two ways. First, linkage analysis was performed in a sample of 24 families multiply affected with schizophrenia. The genotypes were studied for GT12 (D21S210), a highly polymorphic microsatellite marker at the APP locus. Second, we used single strand conformation analysis (SSCA) to screen for mutations in exon 17 of APP in one affected member from each family and in a sample of 44 unrelated patients. In addition, we looked for linkage between schizophrenia and a series of highly polymorphic markers situated at approximately 20cM intervals along the long arm of chromosome 21. We were unable to find evidence for linkage to GT12 or the other markers studied. SSCA did not reveal any mutations in exon 17 of AP. We conclude that mutations within APP are an unlikely cause of schizophrenia. Moreover, this study provides no evidence for a major gene for schizophrenia on chromosome 21, and linkage can be excluded from much of this region under some genetic models.

The lymphoblast beta-adrenergic receptor in bipolar depressed patients: characterization and down-regulation

beta-Adrenergic receptor binding and adenylyl cyclase activity were examined in lymphoblast cell lines established from 12 patients with bipolar disorder and 10 unrelated healthy control subjects. No significant differences were found in [125I]iodocyanopindolol binding affinity or capacity or in isoprenaline-stimulated cAMP response. Incubation of lymphoblasts with isoprenaline (1 nM) for 24 h prior to assay reduced both receptor number and adenylyl cyclase activity. The extent of receptor down-regulation was significantly less in cells of bipolar disorder patients (20 +/- 5%) compared to controls (40 +/- 4%). Desensitization of adenylyl cyclase, however, was reduced to a similar degree in bipolar (65 +/- 14%) and control (68 +/- 20%) subjects. We conclude that basal beta-adrenergic receptor characteristics are not altered in bipolar disorder but that agonist down-regulation of receptor number may be less efficient than in control cells. The functional implications of this effect are discussed.

Exclusion of a schizophrenia susceptibility gene from the chromosome 5q11-q13 region: new data and a reanalysis of previous reports

The report of a putative schizophrenia susceptibility gene linked to markers in the chromosome 5q11-q13 region and subsequent failures of replication have provoked considerable controversy. We here report six Welsh families multiply affected with schizophrenia in which there is no evidence for linkage between a dominant-like schizophrenia gene and 5q11-q13 markers. It is argued that our new results together with a combined reanalysis of previous studies suggest that a schizophrenia susceptibility gene can be excluded from the 5q11-q13 region. The apparent disparities between published results are most likely to reflect a chance finding in the one positive study and probably should not be interpreted as resulting from true linkage heterogeneity.

The relationship of the rat brain 68 kDa microtubule-associated protein with synaptosomal plasma membranes and with the Drosophila 70 kDa heat-shock protein

A protein of molecular mass 68 kDa and pI5.6 is a major translation product of rat brain mRNA [Hall, Mahadevan, Whatley, Biswas & Lim (1984) Biochem. J. 219, 751-761]. In the rat brain this protein was associated with microtubule preparations and was present together with tubulin as a component of the synaptosomal plasma membranes, synaptic vesicles and post-synaptic structures. The brain mRNA for this protein was found to hybridize specifically to the Drosophila gene for the 70 kDa heat-shock protein, thus enabling its rapid isolation.

Characterization of translation products of the polyadenylated RNA of free and membrane-bound polyribosomes of rat forebrain

Poly(A)+ RNA (polyadenylated RNA) isolated from membrane-bound and free polyribosomes was translated in reticulocyte lysates, and the products were analysed by two-dimensional gel electrophoresis. Several translation products were specific to membrane-bound polyribosomal mRNA, including polypeptides of 47kDa, 35kDa and 21 kDa, whereas others (e.g. of 37 kDa, 17 kDa and 14 kDa) were specific to free polyribosomal mRNA. Although many products were common to both mRNA species, cross-contamination could be ruled out on the basis of the presence of these and other specific products. The common products included a 68 kDa microtubule-associated protein, tubulin, actin, the brain form of creatine kinase, neuron-specific enolase and protein 14-3-3 and calmodulin, all of which were identified on the basis of two-dimensional gel and peptide analyses. The 35 kDa protein product of membrane-specific mRNA was co-translationally processed in vitro by microsomal membranes, resulting in its cleavage to 33 kDa (and partial glycosylation). The 33 kDa processed protein (but not the 35 kDa precursor) was integrated into both dog pancreas and rat brain microsomal membranes. The occurrence of the enzymes and calmodulin as products of membrane-bound polyribosomal mRNA is discussed in the light of their presence on rat brain synaptic plasma membranes [Lim, Hall, Leung, Mahadevan & Whatley (1983) J. Neurochem. 41, 1177-1182] and their existence in a specific component of axonal flow. It is suggested that some of these translation products of the rough endoplasmic reticulum may represent proteins destined for the plasma membrane. However, the identity and location of the 35 kDa membrane-specific product (or its processed form) still remain unestablished.

Neurone-specific enolase and creatine phosphokinase are protein components of rat brain synaptic plasma membranes

Neuron-specific enolase and creatine phosphokinase were found, by 2-dimensional gel analysis, in rat brain synaptic plasma membranes (SPM). The identity of these enzymes was confirmed by comigration with purified rat brain NSE and CPK and by peptide analysis. The specific enzymatic activities of enolase and creatine phosphokinase, as well as of pyruvate kinase, also present on the membranes, were comparable to those in the homogenates when these three enzymes were fully activated. In the SPM all three enzymes, particularly enolase, were partially cryptic in that enzymatic activities were very low unless the membranes were treated with Triton X-100. They were resistant to both low-salt and high-salt extraction and to trypsin, except when Triton X-100 was present. These results suggest that the enzymes are tightly bound protein components of the membrane and that they may constitute an assembly capable of generating ATP.

Evidence that transcription changes in ageing cultures are terminal events occurring after the expression of a reduced replicative potential

There is a progressive decline in replicative capacity with increasing age as expressed in terms of percentage labelled nuclei with 3H-thymidine and altered saturation density at confluency. This expression of ageing in vitro is seen in three different lines of human embryo diploid fibroblasts, although the pattern and rate of decline is different in each case. Generalization about in vitro ageing from studies with one cell line should therefore be made with care or avoided. There was an increase in total cellular RNA content as cultures aged which was more pronounced as cells entered the senescent or terminal phase of their lifespan. This increase appeared to be accompanied by a slightly elevated uptake and incorporation of 3H-uridine per cell. Template activity of isolated nuclei was markedly reduced in very late passage or phase III cells, but did not show a progressive decline with increasing age. These studies show that there is a reduced replicative potential which is not accompanied by a detectable decline in transcription, and suggest that the altered template activity should be regarded as an effect of ageing in vitro.

Resistance to Mycoplasma synoviae is bursal dependent

Bursectomizing small bursa line birds produced susceptibility to Mycoplasma synoviae. This suggested that M. synoviae is B cell dependent, but does not rule out a T cell effect.