A geostatistical approach to the analysis of pattern in rare disease

The incidences of human disease vary from place to place, and some show distinct patterns. Patterns in rare diseases, such as childhood cancer, are not readily discernible, however, and this makes it difficult to relate their distribution to factors in the environment in seeking possible causes of the disease. Provided cases are geographically indexed, data on a disease can be analysed geostatistically. Variograms can be computed to determine the strength and spatial scale of any pattern, and to summarize the variation, and then the risk of developing the disease can be estimated by kriging. This has been done for the incidence rates of childhood cancer from 1980 to 1984 in the West Midlands Health Authority Region of England. A novel modification was made to compute the variogram of the risk from that of the frequencies, taking into account the binomial nature of the data. The incidence of the disease appears patchy. The results show that this patchiness is spatially correlated and not purely random. The risk appears greatest in the rural south west of the Region and in some of the suburbs around the conurbation. This approach using geostatistics seems very promising and will be developed further as more data for this and other diseases become available.

Childhood cancer in the West Midlands: incidence and survival, 1980-1984, in a multi-ethnic population

The purpose of this study is to describe the incidence and survival of childhood cancer in the West Midlands for the period 1980-1984. Proportional breakdown by Asian subgroup is also considered. A total of 587 patients were registered, 49 of them of Asian origin. Breakdown to Asian versus non-Asian subgroups by diagnosis revealed comparatively high rates for Hodgkin's disease, retinoblastoma and neuroblastoma in the Asian patients. However, a deficit of cases was seen for CNS tumours. Comparison of overall age-standardized rates (ASR) for all cancers revealed a substantially lower value compared to that reported for the USA white population but a similar value to the USA black and UK white populations. Diagnostic breakdown revealed that the major difference between the West Midlands Regional Children's Tumour Research Group (WMRCTRG) and the USA white ASR was in the leukaemia and lymphoma group. Overall survival for the series was 56% at 5 years. The poorest prognosis was found in acute myeloid leukaemia, with only 23% of patients surviving at 5 years, against 62% in acute lymphoblastic leukaemia. CNS tumours also had a poor outcome, with an overall survival rate of 47%, although certain individual diagnoses were more favourable. We observed a 100% survival rate in Hodgkin's disease up to 5 years from diagnosis, and both Wilms' tumour and retinoblastoma had 90% survival rates.

Descriptive epidemiology of primary central nervous system tumours in children: a population-based study

This study was undertaken to investigate the incidence, outcome and referral patterns of central nervous system tumours in a defined childhood population over a recent 5-year period. The study incorporated pathological review of all available diagnostic material and follow-up assessed survival at a minimum of 5 years from diagnosis. One hundred and forty-seven cases were reviewed, representing an annual incidence of 26.5 per million children aged less than 15 years. The distribution of individual diagnoses by age, sex and anatomical site was similar to comparable data collected previously in the United Kingdom and North America, but the inclusion of 28 cases (19%) without biopsy suggested that the wider use of computed tomography might account for a small increase in incidence over previous estimates. Analysis of referral to the Regional Paediatric Oncology Unit showed that the patients referred were younger than those not referred and were over-represented amongst the diagnoses of medulloblastoma, ependymoma and brain stem glioma, which carry the worst prognosis. Survival for all diagnoses together was 51% at 5 years, ranging from 13% for unbiopsied brain stem gliomas to 100% for juvenile astrocytomas. Referral to the Regional Unit appeared to have some survival advantage for children with medulloblastoma, although this was not statistically significant. Accurately reviewed data such as these are essential in order to assess current workload and treatment success, in addition to enabling investigation of future diagnostic and treatment strategies.

Malnutrition at diagnosis of malignancy in childhood: common but mostly missed

A prospective, controlled study of nutritional status in 100 newly diagnosed paediatric oncology patients is reported. Results showed that although patients' height-for-age and weight-for-height were normal, mid-upper arm circumference (MUAC) and triceps skinfold thickness (TSFT) were significantly less than reference and control values. Moreover, 20% of patients had MUAC below the 5th percentile (P less than 0.001) and 23% had TSFT more than 2 SD below the mean (P less than 0.001). The discrepancy between these assessments is attributed to the effect of large tumour masses masking diminished true body weight. Children with intra-abdominal solid tumours had significantly lower MUAC and TSFT than those with either extra-abdominal solid tumours or leukaemia, and were more likely to be malnourished based on arm anthropometric criteria. Of all subjects, 44% were consuming less than 80% of their recommended daily allowance of energy at diagnosis, compared with 0% of controls (P = 0.001).

'Clustering'--real or apparent? Probability maps of childhood cancer in the West Midlands Health Authority region

The West Midlands Regional Children's Tumour Registry collects detailed information on all cases of childhood cancer in the West Midlands Health Authority Region (WMHAR). The distribution by electoral ward of all cases diagnosed in the WMHAR between 1980 and 1984 has been determined. Analysis has also been performed for leukaemias/non-Hodgkin's lymphomas alone. We suggest that this latter grouping should be universally employed, owing to the difficulty of accurately separating out cases of leukaemia. Both spatial analyses showed several wards with significantly excessive rates on the basis of their cumulative Poison probability. Observed/expected ratios of 3-35 were seen for cases in significant wards, which are similar to the ratios seen in analysis of incidence around nuclear installations. However, further detailed consideration of these individual significance levels in the light of the number of statistically significant wards which would occur by chance alone, due to the multiple use of the test, accounted completely for the number of wards obtained in each of the groups considered. Thus, apparent 'clustering' of cases could be mere statistical artefact. In the WMHAR, therefore, using the technique of probability mapping, no true spatial pattern of incidence was found, other than that which would occur by chance alone. This, in a large area without nuclear installations and an even mix of rural and industrialised regions, could be seen as control data for those studies which have considered cases of childhood leukaemia around nuclear facilities, where the observation of single point clusters associated with suspected sites restricts assessments of spatial pattern in the rest of the area.(ABSTRACT TRUNCATED AT 250 WORDS)

Increasing incidence of retinoblastoma?

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Abnormal thyroid hormone and thyrotropin levels in homozygous sickle cell disease

Male patients with SS disease had significantly lower T3 and higher TSH levels than a comparison group. Stimulation with TRH in 10 male sibling pairs showed highly significant increases in T3 and TSH in both patients and sibling controls although the increase in TSH was significantly greater in SS disease. The interpretation of these findings is unclear although the thyroid indices indicate an abnormal pituitary-thyroid axis most consistent with a modest primary thyroid failure.

A variant form of Bernard-Soulier syndrome: mild haemostatic defect associated with partial platelet GPIb deficiency

Platelets from patients with Bernard-Soulier syndrome (BSS) are larger than normal and demonstrate characteristic aggregation abnormalities. A molecular defect involving platelet membrane glycoproteins has been established as the primary abnormality, and the major defect is described as an absence of GPIb, the receptor for von Willebrand factor, which prevents the adhesion of BSS platelets to damaged endothelium. Associated deficiencies of GPV and GPIX are also recognized. The overall clinical effect is a haemorrhagic tendency which, although variable, is severe at times in all patients. We report a child who presented with the typical morphological and aggregation abnormalities associated with BSS, but who had negligible bleeding problems. Further investigation revealed a significant but incomplete deficiency of GPIb and of GPV and GPIX. This case suggests that BSS may be a heterogeneous disorder with clinical consequences dependent on the extent and complexity of the platelet membrane glycoprotein deficiency.

Urea kinetics in adults with homozygous sickle cell disease

The kinetics of urea metabolism were measured in four adults with homozygous sickle cell disease (HbSS). On a dietary intake of 1.2 to 2.7 g protein/kg/d the rate of urea production was 188 to 277 mg nitrogen/kg/d. A relatively small proportion of the urea was excreted in the urine (40 per cent), with a high fixed rate of hydrolysis in the bowel, 145 mg nitrogen/kg/d. Although 50 per cent of the nitrogen from hydrolysed urea was resynthesized to urea, and a further 10 per cent may have been lost in the stool, it is estimated that 58 mg nitrogen/kg/d was available for synthetic metabolic activity. Urea kinetics in sickle cell disease subjects are markedly different from normals, and this may be a reflection of the metabolic demands for increased red cell synthesis.

Facts for teachers of children with cancer

As the prospects of cure for children with cancer increase, the long term consequences of treatment and the quality of life experienced by survivors assume greater importance. Strategies to encourage early return to school after diagnosis are of considerable importance both educationally and socially, but teachers require information to help them facilitate the child's return. The extent to which professional contact is fostered between children's cancer centres and the education service is the subject of this short survey.

Intracardiac thrombus and tricuspid valve obstruction: a complication of Hickman catheter use

The risk of catheter-related sepsis is well recognized in immunocompromised patients with an indwelling central venous line, but the hazard of thrombus involving the right atrium is less well known. We report the case of a child who died after intraartrial thrombus obstructed the tricuspid valve. The predisposing factors and available treatment strategies are discussed.

Early congenital syphilis and severe haematological disturbance

The early clinical signs and symptoms of congenital syphilis are diverse but, if undiagnosed, signs of the disease may subside until the late stigmata appear. We report a case that illustrates that the haematological signs and symptoms may be so severe as to mimic a diagnosis of leukaemia or disseminated malignant disease.

Prepubertal growth and skeletal maturation in children with sickle cell disease

In a longitudinal study of 298 children with homozygous sickle cell (SS) disease and 157 children with hemoglobin SC disease, between birth and 9 years of age, observations of weight and height were made. These were compared with similar data derived from an age- and sex-matched group of 231 children with a normal hemoglobin (AA) genotype. Growth in children with SC disease was not significantly different from that in normal children, but children with SS disease had statistically significant, and progressive, deficits in both weight and height before 2 years of age. The average deficit approached 1 SD below the normal mean for age by 9 years. Observations of skeletal maturity, based on radiologic assessment of bone age at the wrist, were made on a proportion of these children at 5 and 8 years of age. Children with SS disease were significantly retarded at 8 years but not 5 years, which is consistent with increasing deficit in height. These observations confirm the early impact of SS disease on physical development and provide standards from which clinical expectations of growth may be derived. The relevance of these findings and their relationship to the characteristic delay in pubertal development is discussed together with a review of possible etiologic factors. The benign nature of SC disease is endorsed by the absence of an effect on growth in the prepubertal child.

Alpha thalassemia and the hematology of homozygous sickle cell disease in childhood

alpha Thalassemia modifies the hematologic expression of homozygous sickle cell (SS) disease, resulting in increased total hemoglobin and HbA2 and decreased HbF, mean cell volume, reticulocytes, irreversibly sickled cells, and bilirubin levels. The age at which these changes develop in children with SS disease is unknown. Ascertainment of globin gene status in a large representative sample of children with SS disease has afforded an opportunity to study the hematologic indices in nine children homozygous for alpha thalassemia 2 (two-gene group), 90 children heterozygous for alpha thalassemia 2 (three-gene group), and 167 children with a normal alpha globin gene complement (four-gene group). The two-gene group had significantly lower mean cell volumes from birth, higher red cell counts from one month, lower reticulocytes from three months, and higher HbA2 levels from one year, as compared with the four-gene group. Children with three genes had intermediate indices but resembled more closely the four-gene group. Differences in total hemoglobin or in fetal hemoglobin between the groups were not apparent by eight years of age. The most characteristic differences of the two-gene group were the raised proportional HbA2 level and low mean cell volume, the latter having some predictive value for alpha thalassemia status at birth.

Haematological change in sickle cell-haemoglobin C disease and in sickle cell-beta thalassaemia: a cohort study from birth

The haematological changes in early years following neonatal diagnosis have been observed in representative groups of children with sickle cell-haemoglobin C (SC) disease, sickle cell-beta(+) thalassaemia, and in sickle cell-beta(0) thalassaemia. Most haematological indices in SC disease were intermediate between previously published values in SS disease and in AA controls, generally being closer to values in normal children. Exceptions were microcytosis which may be genetically determined and a striking elevation of mean cell haemoglobin concentration from age 2 months to 4 years. The combination of a raised MCHC and a lowered MCV is unusual and may be characteristic of SC disease. Features in sickle cell-beta thalassaemia generally differed according to the type of beta thalassaemia gene. Sickle cell-beta(0) thalassaemia had lower levels of haemoglobin, MCHC, red cell count, MCV, and higher reticulocytes, most differences being significant before 1 year. No differences between S beta(0) thalassaemia and S beta(+) thalassaemia were apparent in HbF levels (which resembled those in SS disease) or in HbA2 levels (which exceeded those in SS disease by 1 year of age).

Body shape in young children with homozygous sickle cell disease

Body shape, defined by detailed anthropometric measurement, was compared in 64 children with homozygous sickle cell (SS) disease, and in 123 children with a normal hemoglobin (AA) genotype, aged 4 to 6 years. Children with homozygous sickle cell disease showed an average reduction in weight, height, sitting height, limb length, interacromial and intercristal diameters, and skinfold thickness. They showed increased anteroposterior chest diameters with an increased anteroposterior-lateral chest diameter ratio. This report establishes that the effect of homozygous sickle cell disease on growth patterns in childhood is apparent before the age of 6 years. The relationship to changes in body shape, seen during adolescence and in affected adults, and their possible determinants, are discussed.

Sickle cell-Hb Lepore Boston syndrome. Uncommon differential diagnosis to homozygous sickle cell disease

Two siblings assumed on the basis of clinical and hematological evidence to have homozygous sickle cell (SS) disease were found to have a mother without sickle hemoglobin. Subsequent investigation and hemoglobin structural studies indicated the diagnosis to be sickle cell-Hb Lepore Boston syndrome. This syndrome generally manifests clinically significant sickle cell disease, and this genotype should be borne in mind in apparent SS disease where a parent without sickle hemoglobin in discovered.

Acute splenic sequestration and hypersplenism in the first five years in homozygous sickle cell disease

A cord blood screening programme initiated in June 1973 had screened 68 000 normal deliveries by February 1979 with the detection of 216 cases of homozygous sickle cell disease. Regular review of these children in the Medical Research Council paediatric clinic has identified acute splenic sequestration as a major cause of morbidity and mortality in the first 5 years of life. In addition to classical episodes characterised by peripheral circulatory failure, minor episodes of increasing anaemia associated with an enlarging spleen and an active marrow were also common. These minor episodes appeared to have predictive value in children who later developed severe life-threatening episodes of acute splenic sequestration. Sequestration. Sustained hypersplenism was also appreciably more common in children developing minor or major episodes of acute splenic sequestration compared with those without such a history. It is proposed that the classification of acute splenic sequestration be expanded to include these minor episodes, and that consideration be given to prevention of recurrences by splenectomy particularly in patients who also develop sustained hypersplenism.

Observations on the natural history of dactylitis in homozygous sickle cell disease

The incidence of the hand-foot syndrome (dactylitis) has been studied in a group of 233 children with homozygous sickle cell (SS) disease followed prospectively from birth. Dactylitis affected 45% of the children by the age of 2 years, with most cases occurring before this age. Episodes were significantly more common during colder months of the year, similar to the seasonal relationship previously noted in painful crises. Comparison of hematologic indices at age 6 months in patients with and without development of dactylitis indicated a lower fetal hemoglobin and higher reticulocyte counts in affected patients. The occurrence of dactylitis in combination with low fetal hemoglobin may serve to identify high-risk patients with SS disease.

Fetal hemoglobin and clinical severity of homozygous sickle cell disease in early childhood

The relationship of the clinical features of homozygous sickle cell disease in the first two years of life to the level of fetal hemoglobin at age 6 months was investigated. Mean HgbF levels were significantly lower in children manifesting early palpable splenomegaly, dactylitis, acute splenic sequestration, and in those who died. The risks of dactylitis and ASS were significantly greater in patients with lower HgbF levels. Since early splenomegaly itself may increase the risks of ASS, infection, and death, the relationship of HgbF to these features was further analyzed within the early splenomegaly group. The results suggest that a low HgbF may have a direct effect on the etiology of ASS, but any effect on infection or death is probably mediated via its relationship with the appearance of a palpable spleen. A protective effect of a high HgbF on the risk of dactylitis was demonstrated coincident with the accepted theory of its pathogenesis. Early HgbF determinations may be of value in identifying patients at high risk of serious complications during infancy.

Fasting metabolism in infants. I. Effect of severe undernutrition on energy and protein utilization

Fasting energy metabolism was studied in infants to determine the rates of utilization of endogenous carbohydrate, fat, and protein in relation to length of fasting, glucose homeostasis, other circulating energy substrates and hormones, and severe depletion of energy reserves due to prior malnutrition. Five subjects about 1 yr of age were each studied before and after restoration of their energy reserves. Following 3 days of a standard maintenance intake of energy and protein, the subjects were fasted until glycogen oxidation became negligible. Total energy utilization, determined by hourly oxygen consumption, did not diminish as a result of fasting but was significantly less when malnourished than when recovered, 66 versus 79 kcal/kg/day. In all cases the major energy source shifted from oxidation of dietary carbohydrate and glycogen to oxidation of fat, determined from the respiratory quotient, until the oxidation of glycogen became negligible and fat provided 94% of energy in the malnourished subjects after 21 hr and 92% in the recovered subjects after 27 hr. Utilization of protein, determined from urinary nitrogen excretion, remained very low in the malnourished infants accounting for a maximum of 4% of energy, 103 mg N/kg/day, whereas after recovery, protein utilization doubled as a result of fasting, finally accounting for 7% of energy, 226 mg N/kg/day (p less than 0.005). Urea accounted for 60% of total urinary N in both groups and plasma urea increased correspondingly in the recovered but not in the malnourished subjects. Plasma glucose decreased to about 40 mg/100 ml in both groups as glycogen oxidation diminished. The maximum amount of glucose that could have been derived from dietary carbohydrate, glycogen, glycerol, and amino acids decreased over this time from about 6 to 1 mg/kg/min. Alanine declined in relation to glucose concentration and was not different in the two groups in spite of the difference in urea production. Glycerol free fatty acids, beta-hydroxybutyrate, and acetoacetate increased in both groups, but the latter three of these remained significantly less in the malnourished group. Insulin decreased rapidly and remained equally low in both groups. Urinary epinephrine increased in both groups and cortisol was elevated after fasting, while growth hormone did not increase significantly. It is concluded that fasting infants complete the transition from dietary carbohydrate to endogenous fat as the major energy source much faster than do adults, proportionate to relatively greater energy utilization. Severe wasting did not prevent energy homeostasis in spite of greatly depleted body fat. Oxidation of fat continued to provide virtually all of the fasting energy requirements, although ketosis was relatively less. Utilization of endogenous protein also increased as a result of fasting but, by contrast, provided only a very small fraction of total energy, and this was substantially diminished as a result of wasting, similar to what has been found in starved adults...