Somatic overgrowth associated with overexpression of insulin-like growth factor II

Overexpression of the normally imprinted fetal insulin-like growth factor II (IGF2) has been implicated in the pathogenesis of the cancer-predisposing Beckwith-Wiedemann syndrome (BWS). We have detected constitutional relaxation of imprinting of IGF2 in four children with somatic overgrowth who do not show diagnostic features of BWS. Three children showed constitutional abnormalities of H19 methylation. All four children showed nephromegaly and two developed Wilms' tumors. Gene methylation is known to be associated with gene silencing, and three children showed constitutional abnormalities of H19 gene methylation. Disruption of H19 methylation, and concomitant relaxation of IGF2 imprinting, provides another mechanism that can increase IGF2 expression in children with overgrowth. The accumulated data on normal and pathologic IGF2 expression are now sufficient to define an entity, "IGF2 overgrowth disorder," of which BWS may be one extreme manifestation. These findings have broad implications for the characterization of idiopathic overgrowth.

Fibrogenesis imperfecta ossium

The clinical features, investigation, treatment and outcome of two adults with fibrogenesis imperfecta ossium are described. In this rare acquired disorder of bone, normal lamellar collagen is replaced by structurally unsound collagen-deficient tissue, which leads to extreme bone fragility and ununited fractures. Transmission microscopy and SEM showed striking ultrastructural changes in bone structure and mineralisation. Both patients had monoclonal IgG paraproteins in the plasma and one excreted monoclonal lambda light chains in the urine. No abnormal plasma cells were found in the bone marrow and there was no evidence of amyloid deposition in the tissues. In both patients initial treatment with 1 alpha-hydroxycholecalciferol appeared to be ineffective, but in one, repeated courses of melphalan and corticosteroids over three years together with 1 alpha-hydroxycholecalciferol produced striking clinical and histological improvement. The findings in these and other patients strongly suggest that paraproteinaemia is an integral feature of fibrogenesis imperfecta ossium, and this needs further investigation.

Fibrogenesis imperfecta ossium

The clinical features, investigation, treatment and outcome of two adults with fibrogenesis imperfecta ossium are described. In this rare acquired disorder of bone, normal lamellar collagen is replaced by structurally unsound collagen-deficient tissue, which leads to extreme bone fragility and ununited fractures. Transmission microscopy and SEM showed striking ultrastructural changes in bone structure and mineralisation. Both patients had monoclonal IgG paraproteins in the plasma and one excreted monoclonal lambda light chains in the urine. No abnormal plasma cells were found in the bone marrow and there was no evidence of amyloid deposition in the tissues. In both patients initial treatment with 1 alpha-hydroxycholecalciferol appeared to be ineffective, but in one, repeated courses of melphalan and corticosteroids over three years together with 1 alpha-hydroxycholecalciferol produced striking clinical and histological improvement. The findings in these and other patients strongly suggest that paraproteinaemia is an integral feature of fibrogenesis imperfecta ossium, and this needs further investigation.

Severe intrauterine growth retardation with increased mitomycin C sensitivity: a further chromosome breakage syndrome

We report an infant with pre- and postnatal microcephaly and growth retardation, a distinctive face, and developmental delay. The initial diagnosis was of Seckel syndrome. He became pancytopenic at 16 months and died soon after. His bone marrow was of normal cellularity but had a small lymphocyte infiltration. Increased spontaneous chromosome breakage was seen in blood and fibroblasts. Mitomycin C induced chromosome damage was increased and comparable to that seen in Fanconi anaemia. Reports of similar patients are reviewed. This entity of severe intrauterine growth retardation and increased mitomycin C sensitivity is hypothesised to be a distinct chromosome breakage syndrome.

Organization and fine structure of a pacemaker derived from fetal rat myocardium

At an unknown point in mammalian development, cardiac precursor cells become committed to the cardiocyte phenotype. Certain of these are believed to specialize further into pacemaker cardiocytes. By culturing explanted embryonic ventricles into in vivo organ culture (Tucker DC, Snider C, Woods WT Jr: Pediatr Res 23:637-642, 1988), we observed pacemaker cells arising apparently from cardiocytes. We hypothesized that this event can be triggered by intercellular attachments, innervation, vascularization, or other factors. The present study was designed to test the hypothesis that primitive ventricular cells in the tubular heart can organize into an anatomically and electrophysiologically distinct pacemaker structure in the absence of innervation or vascularization from extrinsic sources. Developing ventricles of tubular hearts from 10-d-old rat embryos (n = 22) were excised and incubated in culture dishes. Within each explant, a group of cells organized into a uniform cluster (diameter, 150 +/- 50 microns) after 8 +/- 2 d in culture. These cells resembled immature conduction system cells and had electrophysiologic features similar to those of mature pacemaker cells. Single-cell action potentials and impulse conduction patterns proved that the pacemaker cluster was the dominant pacemaker for the entire explant. These results confirm that, in the absence of extrinsic nerves and blood vessels, culture of the tubular ventricle elicits formation of an organized pacemaker, resembling the mature cardiac pacemaker and suggesting that contact with the culture dish surface or some other factor triggers conversion of cardiocytes to the pacemaker phenotype.

'Disorganization-like syndrome' with 47,XXY and unilateral narrowing of the common iliac artery

We described a male infant with a spectrum of anomalies compatible with the diagnosis of 'disorganization-like syndrome'. The infant had a partial foot arising from the right buttock, an absent right kidney, and a shortened right leg with severe non-positional talipes equinovarus. The infant's karyotype was 47,XXY. The right common iliac artery was one half of the expected diameter. The limb reduction defect seen in this case of disorganization (Ds) may have had a vascular aetiology.

Asymmetry and skin pigmentary anomalies in chromosome mosaicism

We report six persons mosaic for a chromosome anomaly. All were mentally retarded and dysmorphic. Unilateral or asymmetrical features were found in all cases, in one an unusual transverse terminal limb anomaly, and in the others various degrees of hemiatrophy of the left side of the body. Five of the subjects had skin pigmentary anomalies which were distributed in the lines of Blaschko. The abnormal cell lines found were ring chromosome 22, trisomy 22, a large acrocentric marker, a deletion of 18q, a deletion of 8q, and triploidy. In four cases the clinical diagnosis was only confirmed by skin biopsy. In one case low level mosaicism in blood was fortuitously detected because of cytogenetic fragile X screening and confirmed in a skin biopsy. The sixth case was of dynamic mosaicism of a non-mosaic deletion 18q with a chromosome 18 derived marker present in a proportion of cells. Chromosome mosaicisn may cause subtle and asymmetrical clinical features and can require repeated cytogenetic investigations. The diagnosis should be actively sought as it enables accurate genetic counselling to be given.

Two sibs who are double heterozygotes for achondroplasia and pseudoachondroplastic dysplasia

We report a family in which two sibs have both achondroplasia and pseudoachondroplastic dysplasia. The mother has achondroplasia and the father has pseudoachondroplastic dysplasia, which he had inherited from his father. Both children appeared typical of achondroplasia at birth. By 1 1/2 years they had developed a fixed lumbar kyphosis with gibbus and had additional x ray changes unusual for just achondroplasia and suggestive of pseudoachondroplastic dysplasia. Subsequently both children have shown characteristic features of both conditions and have grown less well than expected for achondroplasia. Radiographs show the striking synergistic effects of the two conditions. MRI in both sibs confirmed brain stem compression at the foramen magnum. This may be an important complication and should be actively sought in any double heterozygote.

Effectiveness of workplace accommodations for a corporate telephone operator with a full left-arm prosthesis: A case study

A corporate telephone operator and voice mail programmer was involved in a serious automobile accident resulting in left-arm amputation and through rehabilitation received a full left-arm prosthesis. Upon returning to work in her previous job capacity, some work activities and work area configurations were identified as problematic during task performance. Work methods and work area configuration were evaluated regarding their appropriateness for supporting return to work and long-term accommodation. Job activity analysis determined all reaches, clearances, and forces and their compliance with recommended criteria. A body part comfort/discomfort survey (BPCDS) was administered pre- and post-accommodation to elicit information regarding workplace problem areas and provide a measure to assess accommodation effectiveness. Workstation, support equipment, work area, seating, task assignments, and work methods were modified to more appropriately support operator task performance. Comparison of pre- and post-accommodation BPCDS indicates a significant reduction in operator discomfort with residual discomfort associated with the orthopedic prosthesis. This case study illustrates the use of the principles and techniques of industrial ergonomics to develop workplace accommodations. The area of ergonomics, medical ergonomics,is an example of the development of reasonable accommodations for physically challenged workers in the spirit of compliance with the Americans with Disabilities Act (ADA).

Neither uniparental disomy nor skewed X-inactivation explains Rett syndrome

The locus DXS255 was studied using the probe M27 beta in ten probands with Rett syndrome and in eight of their families. No evidence of uniparental disomy of the X chromosome was detected, as all informative probands had inherited an allele from each of their parents. Differential methylation of a CCGG site within the DXS255 locus as shown by digestion with MspI/HpaII, revealed moderate skewing of X-inactivation favouring the maternal allele in two of the probands. Random X-inactivation was present in all mothers tested and in two unaffected sisters. Three of four unaffected siblings had inherited the same maternal allele at DXS255.

Skeletal muscle bioenergetics in myotonic dystrophy

Skeletal muscle function of 15 patients with myotonic dystrophy (dystrophia myotonica, DM) was investigated using 31P magnetic resonance spectroscopy to evaluate bioenergetics and intracellular pH at rest and during exercise and recovery. Results from DM patients, normal controls and mitochondrial myopathy patients were compared in order to assess the possible contribution of abnormal mitochondrial metabolism to muscle dysfunction in DM. In resting DM muscle, intracellular pH (pHi) was normal, but there were significant elevations in the concentration ratios of Pi/ATP, phosphomonoesters/ATP and phosphodiesters/ATP. In patients with the most severe exercise intolerance the phosphocreatine/ATP ratio was also reduced. Resting muscle of 11 mitochondrial myopathy patients showed similar changes to those of the most exercise-intolerant DM patients. In exercising DM muscle, energy stores were rapidly depleted as in mitochondrial myopathy. Muscle acidified in all subjects, but in DM the decrease in pHi was less than in normal muscle. Recovery half-times for phosphocreatine, Pi and ADP were normal in DM but slow in mitochondrial myopathy. The initial rate of phosphocreatine repletion after exercise was rapid in DM, consistent with high [ADP], but slow in mitochondrial myopathy in spite of elevated [ADP]. Because recovery is an oxidative process, we conclude that there was no decrease in the oxidative capacity of the muscles in this group of DM patients. In the subjects in whom it could be measured, the rate of recovery of intracellular pH was greater in the 3 DM patients (0.14, 0.15 and 0.16 U/min) than in the 7 normal controls (0.08-0.12 U/min, mean 0.10). The results do not rule out a minor abnormality in glycogenolysis, but they suggest that the failure to acidify normally during exercise is probably due to rapid proton efflux.

Dialysis arthropathy of the hip

Beta 2-microglobulin amyloid deposition is associated with a destructive arthropathy in the hip of chronic hemodialysis patients. Twenty-five hips from 18 patients were assessed for the presence and immunohistochemical type of amyloid. The hemodialysis group was compared with an age- and disease-matched control group that had no evidence of renal failure. Beta 2-microglobulin amyloid deposits were present in all patients who had been on hemodialysis for 18 months or more. Beta 2-microglobulin amyloid deposits were not found in patients who had been on hemodialysis for less than 18 months. Amyloid deposits were seen first in the articular cartilage and later involved the synovial membrane, joint capsule, and subchondral bone as well. The presence and amount of amyloid deposition correlated to the duration of hemodialysis. Severely affected hip roentgenographically had a concentric loss of joint space, periarticular erosions, and cystic lesions in the femoral head and acetabulum. These pathologic and roentgenographic changes suggest that amyloid deposition leads directly to the erosive hip arthropathy occurring in hemodialysis patients.

A family showing no evidence of linkage between the ataxia telangiectasia gene and chromosome 11q22-23

We have studied an inbred family in which two cousins presented with the same clinical features of ataxia telangiectasia (AT). Both patients are still ambulatory at ages 25 and 20. Cellular features of both patients are typical of AT and include increased radiosensitivity and an increased level of spontaneously occurring chromosome aberrations in peripheral blood lymphocytes. Linkage studies and haplotype analysis show no clear evidence that the gene for AT in this family is on chromosome 11q22-23. As previously reported AT families from complementation groups AB, C, and D have all shown linkage to this region of 11q22-23. Our study is of importance in suggesting additional locus heterogeneity.

X-inactivation in girls with Rett syndrome

Cytogenetic studies have been carried out on a series of nine girls with Rett syndrome, six of their mothers and nine normal female controls. No abnormality of the X-chromosome has been observed in any subject. X-inactivation studies using various methods of detecting the timing of individual band replication were performed. The overall pattern seen was essentially the same in all subjects, but in the patients with Rett syndrome there may be an alteration in the timing of the X-inactivation process in the region Xp11.3 or 4-->Xp21.

Recessively determined chylous ascites--a case report and possible mouse model

A male infant, whose parents were first cousins, was born with tense chylous ascites, mild generalized oedema and facial dysmorphism. The baby initially seemed well but subsequently probably aspirated, developed septicaemia and finally died at 26 days from a bleeding diathesis, possibly secondary to liver dysfunction. No cause for the chylous ascites was found at post mortem. This case is presumed to represent an example of recessively determined chylous ascites. The mouse mutant Chy may be an homologous condition.

Three sibs with phalangeal anomalies, microcephaly, severe mental retardation, and neurological abnormalities

This paper describes three children of a Pakistani first cousin marriage with a distinctive, non-progressive disorder characterised by variable phalangeal anomalies, microcephaly, pre- and postnatal growth retardation, poor vision, dystonic movements, a characteristic face, and severe mental retardation. This combination of features seems to be distinct and to represent a new autosomal recessive syndrome.

Case report 734. Fibroma of tendon sheath eroding 3rd metatarsal bone

A case is presented of a 37-year-old man with an extrinsic lesion originating in the soft tissue adjacent to the 3rd metatarsal and smoothly eroding the adjacent bone. The operatively confirmed diagnosis of fibroma of tendon sheath was surprising, giant cell tumour of tendon sheath eroding bone being considerably more common; these two lesions are normally impossible to distinguish radiologically.

Ataxia telangiectasia in the British Isles: the clinical and laboratory features of 70 affected individuals

Seventy individuals with ataxia telangiectasia were studied: 29 females and 41 males with an age range of 2 to 42 years. The majority (43/68) presented by 3 years of age with truncal ataxia. All had progressive, handicapping neurological symptoms exhibiting ataxia (70/70), ocular motor apraxia (70/70), an impassive face (70/70), dysarthria (70/70), chorea (68/70), dystonia (55/70) and peripheral neuropathy (50/70). Clinical immune deficiency was present in 43 of 70 patients. Ocular telangiectasia were seen in all but one case and excessive thinness in 54 of 70. The mean age of loss of walking was 10 years and of writing 8 years. All 60 tested showed increased sensitivity to ionizing irradiation, 43 of 48 had an elevated alpha-fetoprotein level and 14 of 21 had an immunoglobulin deficiency. Although there was a marked variation in disease findings sibs were always similar. The heterogeneity seen seems at odds with the unilocus linkage of ataxia telangiectasia to 11q23.

Fibrous dysplasia with locally aggressive malignant change

This is a case report of a tumour which showed all the histological features of fibrous dysplasia without any features of high-grade malignancy, yet had become locally aggressive, causing cortical erosion and extension into soft tissue. Fibrous dysplasia is a well-recognised entity that encompasses monostotic lesions, polyostotic involvement and Albright's syndrome [6, 8]. Lesions in bone usually spare the epiphysis before puberty, but often involve the epiphyseal area after maturity and can progress during adult life [3]. Unless cystic [6, 10] or malignant change [7, 10, 11] occurs, fibrous dysplasia usually remains contained within bone.

Deposition of calcium pyrophosphate dihydrate crystals in a soft tissue chondroma

Calcium pyrophosphate dihydrate (CPPD) crystal deposits were found in an extraarticular chondroma of the soft parts overlying the distal phalanx of the right middle finger. The lesion appeared to arise from the flexor tenosynovium. The pathogenesis of soft tissue chondroma and the relation of cartilage metaplasia to the process of CPPD crystal deposition were investigated.