Inner ear defects induced by null mutation of the isk gene

The isk gene is expressed in many tissues. Pharmacological evidence from the inner ear suggests that isk mediates potassium secretion into the endolymph. To examine the consequences of IsK null mutation on inner ear function, and to produce a system useful for examining the role(s) IsK plays elsewhere, we have produced a mouse strain that carries a disrupted isk locus. Knockout mice exhibit classic shaker/waltzer behavior. Hair cells degenerate, but those of different inner ear organs degenerate at different times. Functionally, we show that in mice lacking isk, the strial marginal cells and the vestibular dark cells of the inner ear are unable to generate an equivalent short circuit current in vitro, indicating a lack of transepithelial potassium secretion.

Maternal and paternal genomes function independently in mouse ova in establishing expression of the imprinted genes Snrpn and Igf2r: no evidence for allelic trans-sensing and counting mechanisms

It has often been suggested that the parental-specific expression of mammalian imprinted genes might be dependent on maternal-paternal intergenomic or interallelic interactions. Using quantitative allele-specific RT-PCR single nucleotide primer extension assays developed for two imprinted genes, Snrpn and Igf2r, we demonstrate: (i) No role for maternal-paternal allelic interactions: the modes of parental-specific expression of Snrpn and Igf2r in normal ova were unchanged in gynogenetic and androgenetic ova; the latter contain two maternal and two paternal genomes respectively, and cannot undergo maternal-paternal interactions. (ii) No role for allelic counting or exclusion mechanisms: in individual blastomeres of androgenetic ova, both paternal Snrpn alleles were active (Snrpn was not expressed in gynogenetic ova), and in individual gynogenetic and androgenetic blastomeres, both maternal and paternal Igf2r alleles, respectively, were active. (iii) No role for ploidy: the mode of parental-specific expression of Snrpn and Igf2r in normal diploid ova was unchanged in individual blastomeres of triploid and tetraploid ova. Thus, the maternal and paternal genomes function independently in establishing the pre-implantation mode of parental-specific expression of Snrpn and Igf2r, with no role for trans-allelic/genomic interaction phenomena. In addition, the results show that inactive and biallelic modes of expression of imprinted genes are potential mechanisms for the death of gynogenones and androgenones at the peri-implantation stage.

Trilateral retinoblastoma. A report of five patients

BACKGROUND

Trilateral retinoblastoma is a well recognized, although rare, syndrome. Most of the reported cases have involved a family history of retinoblastoma (RB) and the disease is almost always fatal. The authors chose to investigate the cases of trilateral retinoblastoma occurring in the West Midlands, a region of the United Kingdom with an increasing incidence of bilateral sporadic RB.

METHODS

Five patients with trilateral retinoblastoma (including two were previously reported), diagnosed in 146 consecutive patients with RB in the West Midlands Health Authority Region between 1957 and 1994, are presented (an incidence of 3%). Their clinical presentation, treatment, and outcome are described.

RESULTS

There were 4 patients with pineoblastoma, only one of whom had a positive family history. The mean age at diagnosis of RB and 6 months, whereas the patients with pineoblastoma were diagnosed at a mean age of 2 years 8 months. The tumors were not evident on the initial computed tomography scans. One child presented with a calcified suprasellar mass 13 months before the bilateral sporadic RB was identified. Death occurred within 1 month of diagnosis of the intracranial tumor in 3 patients who did not receive any treatment. In the other 2 patients who were treated, death occurred at 15 months and 2 years 7 months, respectively, after diagnosis of intracranial tumor.

CONCLUSIONS

Early diagnosis with regular neuro-imaging and more aggressive treatment may improve prognosis in patients with RB and an intracranial tumor.

Ifosfamide nephrotoxicity in children: histopathological features in two cases

We report on two children with rhabdomyosarcoma who received ifosfamide as part of their chemotherapy schedule. Both children subsequently developed severe ifosfamide-induced nephrotoxicity, necessitating electrolyte supplementation. We describe the histopathological findings of renal biopsies performed in these children after the onset of renal dysfunction and comment on the possible mechanisms involved in ifosfamide nephrotoxicity.

The consistent association between Epstein-Barr virus and Hodgkin's disease in children in Kenya

Recent studies have suggested that Epstein-Barr virus (EBV) may play a role in the etiology of Hodgkin's disease (HD). In a previous study, we used a latent membrane protein 1 (LMP1)-specific antibodies to examine archival material from 74 British children with HD and found 50% of cases to be positive. It is known that there are geographic and ethnic variations in the incidence of HD. We have investigated LMP1 status in formalin-fixed, paraffin wax-embedded lymph nodes with HD involvement from 53 children and 48 adults from Kenya using immunohistochemical staining. We also developed sensitive and specific in vitro gene amplification protocols for examining the EBV strain type in such material using several combinations of primers derived from the EBNA 2 and EBNA 3 coding regions. LMP1 positivity was present in 100% of the pediatric cases (two lymphocyte-predominant, 25 nodular sclerosis, 16 mixed cellularity, 5 lymphocyte depletion, and 5 unclassified) and in 66% of the adult cases (two of three lymphocyte-predominant, 26 of 39 nodular, sclerosis, two of two mixed cellularity, and two of four lymphocyte depletion). Tests to type the EBV strain were undertaken in 25 EBV-positive pediatric cases. A combination of type-specific polymerase chain reactions for EBNA 2 and EBNA 3C genes indicated that seven patients had type 1, eight had type 2, and 10 had dual infections with both types. Five cases with dual infections were further investigated using a sensitive in situ hybridization for the EBV-encoded, small nuclear nonpolyadenylated RNAs (EBERs). EBER transcripts were detected in Reed-Sternberg and Hodgkin cells and in occasional infiltrating lymphocytes. These observations indicate that in Kenya EBV is consistently associated with pediatric cases of HD, and that biopsies from a number of such cases appear to carry both type 1 and type 2 viral sequences.

Mouse embryos with paternal duplication of an imprinted chromosome 7 region die at midgestation and lack placental spongiotrophoblast

Imprinted genomic regions have been defined by the production of mice with uniparental inheritance or duplication of homologous chromosome regions. With most of the genome investigated, paternal duplication of only distal chromosomes 7 and 12 results in the lack of offspring, and prenatal lethality is presumed. Aberrant expression of imprinted genes in these two autosomal regions is therefore strongly implicated in the periimplantation lethality of androgenetic embryos. We report that mouse embryos with paternal duplication of distal chromosome 7 (PatDup.d7) die at midgestation and lack placental spongiotrophoblast. Thus, the much earlier death of androgenones must involve paternal duplication of other autosomal regions, acting independently of or synergistically with PatDup.d7. The phenotype observed is similar, if not identical to, that resulting from mutation of the imprinted distal chromosome 7 gene, Mash2, which in normal midgestation embryos exhibits spongiotrophoblast-specific maternally active/paternally inactive (m+/p-) allelic expression. Thus, the simplest explanation for the PatDup.d7 phenotype is p-/p- expression of this gene. We also confirm that PatDup.d7 embryos lack H19 RNA and posses excess Igf2 RNA as might be expected from the parental-specific activities of these genes in normal embryos.

The role of Epstein-Barr virus in Hodgkin's disease from different geographical areas

Recent studies have suggested that Epstein-Barr virus (EBV) may play a role in the aetiology of Hodgkin's disease. To determine the role of EBV in childhood Hodgkin's disease in different geographical areas, immunohistochemical staining and in situ hybridisation were used to analyse latent membrane protein 1 (LMP 1) and small nuclear non-transcribed RNAs (EBER-1) respectively. Testing for EBV within the Reed-Sternberg and Hodgkin's cells was carried out in childhood Hodgkin's disease from 10 different countries. The proportion of LMP 1 positive cases varied significantly, being 50% of cases from the United Kingdom (38/75), South Africa (9/18), Egypt (7/14), and Jordan (8/16), 60% from the United Arab Emirates (6/10), 70% from Australia (11/16), 81% from Costa Rica (34/42), 88% from Iran (7/8), 90% from Greece (20/22), and 100% of the 56 cases from Kenya. A sensitive polymerase chain reaction based EBV strain typing technique was established using archival tissues. EBV strain type 1 was shown to be predominant in childhood Hodgkin's disease from the United Kingdom, South Africa, Australia, and Greece. Type 2 was predominant in Egypt. EBV strain types 1 and 2 were both detected in some cases of childhood Hodgkin's disease in the United Kingdom, Costa Rica, and Kenya. The high incidence of EBV and the presence especially in developing countries of dual infection with both strain types 1 and 2 may reflect socioeconomic conditions leading to malnutrition induced immunological impairment. The possibility of HIV infection also needs to be explored.

Allele-specific expression and total expression levels of imprinted genes during early mouse development: implications for imprinting mechanisms

Genomic imprinting determines the monoallelic expression of a small number of genes during at least later stages of development. To obtain information necessary for the elucidation of imprinting mechanisms, we assessed the allele-specific expression and total expression level of four imprinted genes during early stages of development of normal F1 hybrid mice utilizing quantitative allele-specific reverse transcription-PCR (RT-PCR) single-nucleotide primer extension assays. The Igf2r and Snrpn genes were activated by the early 4-cell stage and exhibited biallelic and monoallelic expression, respectively, throughout preimplantation development. Thus, with respect to different imprinted genes, epigenetic systems determining monoallelic expression are not uniform in their time of establishment. Biallelic expression of Igf2r was observed in single blastomeres, discounting the possibility of random allelic inactivation at this stage. The closely linked H19 and Igf2 genes were activated after the blastocyst stage and often exhibited biallelic and monoallelic expression respectively in tissues of pregastrulation postimplantation-stage embryos, rather than reciprocal monoallelic modes as observed at later stages. This raises the possibility that imprinting of H19 is involved only in the maintenance and not in the initiation of monoallelic expression of Igf2. Monoallelic expression of Snrpn was observed in each blastomere at the 4-cell stage, demonstrating that the germ line, which exhibits biallelic expression of imprinted genes, must be derived from cells in which imprinting was once manifest.

Cancer and congenital abnormalities in Asian children: a population-based study from the West Midlands

Cancer and associated congenital abnormalities were investigated in Muslim and non-Muslim Asian children from the West Midlands. Cancer incidence rates were calculated for Indian (non-Muslim), Pakistani/Bangladeshi (Muslim) and white children diagnosed from 1978 to 1992. Incidence was significantly higher in the Pakistanis, with an age-standardised rate (ASR) of 163 cases per million per year, compared with 115 for Indian and 125 for white children. Among Asian cancer patients, congenital malformations were significantly more common in Muslim (21%) compared with non-Muslim (7%). In Muslims the malformation excess was caused by autosomal recessive and dominant disorders (in 8% and 5% of cases respectively). Cancer malformation/predisposition syndromes were found in 10% of Muslims, compared with 2% of non-Muslims. In 33% of the Muslims with malformations, childhood cancer and a malformation were also present in a close relative. None of the non-Muslims with malformations had a relative with childhood cancer. The cancer excess in Muslims may be partly related to inherited genes causing both malformations and cancer. The prevalence of autosomal recessive disorders may be related to consanguinity, which is common in the Pakistani Muslim population. The high incidence of autosomal dominant disorders may be related to older paternal age at conception, giving rise to spontaneous mutations.

Biallelic expression of imprinted genes in the mouse germ line: implications for erasure, establishment, and mechanisms of genomic imprinting

Genomic imprinting in mammals determines parental-specific (monoallelic) expression of a relatively small number of genes during development. Imprinting must logically be imparted in the germ line, where inherited maternal and paternal imprinting is erased and new imprinting established according to the individual's sex. We have assessed the allele-specific expression of four imprinted genes, two of which exhibit maternal-specific (H19 and Igf2r) and two of which exhibit paternal-specific (Igf2 and Snrpn) monoallelic somatic expression, in the germ line of F1 hybrid mice utilizing quantitative RT-PCR single-nucleotide primer extension assays. The expression of each gene was biallelic in the female and male germ line from the time that migratory mitotic PGCs entered the embryonic genital ridge and throughout gametogenesis, except that H19 RNA was not detected late in gametogenesis. These findings demonstrate that inherited imprinting is erased, or not recognized, in germ cells by the time of genital ridge colonization; also that new imprinting may not be established until late in gametogenesis, or that it is incomplete or not recognized at this stage. Regardless of imprinting status, a generalized neutralization of imprinting is evident in the germ line, associated with the totipotent state of this unique cell lineage.

Changing incidence and geographical distribution of malignant paediatric germ cell tumours in the West Midlands Health Authority region, 1957-92

The West Midlands Regional Children's Tumour Research Group holds high-quality data from 1957 on all childhood cancers in the West Midlands Health Authority region. Since it has been reported that malignant germ cell tumours are increasing in incidence in the north-west of England, we undertook to examine rates in this region and to map the distribution of cases in order to assess any geographical changes in incidence rates. We identified a total of 102 malignant germ cell tumours (MGCTs) between 1957 and 1992. The average age-standardised rate was 1.6 per million per year in the period 1957-74 and 3.6 per million per year during 1975-92, a significant increase (P = 0.0004). Particular increases were noted in older children (10-14 years); P = 0.0002) and in yolk sac (endodermal sinus) tumours (P = 0.004). A small excess was also observed in Asian children when compared with other diagnoses. Geographical analysis showed particularly higher rates at health district level in the West Midlands conurbation as compared with the other areas in the period 1975-92. These factors suggest the possibility that industrial/urban or population effects may be implicated in the observed increase in childhood MGCT and we recommend these areas for further studies.

Clonal diversity, measured by heterogeneity of Ig and TCR gene rearrangements, in some acute leukaemias of childhood is associated with a more aggressive disease

The pattern of immune system gene rearrangements in acute leukaemias of childhood is heterogeneous. The biological significance of this heterogeneity in childhood acute leukaemia is still poorly understood. In this study, we analysed 49 children with acute leukaemia (29 B-precursor acute lymphoblastic leukaemia (ALL), 5 relapsed cALL, 6 T-ALL, 7 acute non-lymphocytic (ANLL) and 2 mixed lineage leukaemias), for the presence of different immune system gene rearrangements (Ig JH, C kappa, C lambda, TCR J gamma, C beta, J delta and J alpha) by Southern blot hybridisation. The most prominent heterogeneity of immune system gene rearrangements was observed in the group of B-precursor ALL. The results from our study suggest that the heterogeneity of immune system gene rearrangement reflects clonal diversity in approximately one-third of patients with B-precursor ALL at presentation and in most patients in relapse. The observed association of clonal diversity with high white blood cell count, pre-B immunophenotype and age under 1 year in B-precursor ALL may have clinical significance. There was a significantly shorter disease-free survival in the group of B-precursor ALL patients with clonal diversity compared with those without clonal diversity. Clonal diversity may, therefore, be a mechanism of disease progression common to different types of aggressive B-precursor ALL.

Immunophenotypic analysis of childhood Burkitt's lymphoma in the West Midlands 1957-1986

AIMS

To analyse the immunophenotype of a large number of non-endemic Burkitt's lymphomas to determine whether a B cell phenotype is consistently recognisable using formalin fixed, paraffin wax embedded archival material and a standard panel of commercially available antibodies.

METHODS

Archival material was obtained from 30 cases of childhood Burkitt's lymphoma registered with the West Midlands Regional Children's Tumour Research Group. These were analysed by a standard avidin biotin complex immunoperoxidase method using antibodies to CD45, CD43, CD30, CD20, CD15, and immunoglobulin heavy and light chains.

RESULTS

There was a high incidence of the CD45RB and CD20 immunophenotypes, with a clearly recognisable B cell lineage even in archival material. IgM was identifiable in 13 of the 23 (56.5%) cases tested. Only three of 17 (18%) cases expressed CD30. Positive membrane staining with CD45RO was observed in two (6.7%) cases.

CONCLUSIONS

A B cell lineage can be identified in Burkitt's lymphoma in formalin fixed, paraffin wax embedded material, even in archival tissue. There was a low incidence of membrane staining with CD45RO which is a potential source of diagnostic confusion.

Quantitative RT-PCR assays show Xist RNA levels are low in mouse female adult tissue, embryos and embryoid bodies

We have investigated expression of the Xist gene in mouse female adult kidney, embryos and embryonic stem (ES) cells undergoing in vitro differentiation as embryoid bodies. Using the quantitative RT-PCR single nucleotide primer extension (SNuPE) assay, we found that the amount of Xist RNA in adult kidney of three mouse strains was less than approximately 2000 transcripts per cell, with only modest differences between strains carrying different Xce alleles. Female embryos 7.5 days post coitum had the same number of Xist transcripts per cell as isogenic adult tissue. Using quantitative oligonucleotide hybridization assays after RT-PCR, we investigated Xist expression in ES lines heterozygous at the Pgk-1 and Xist loci. We found that, while in most (XX) ES lines Xist RNA levels increased during embryoid body formation, the levels seen were less than 10% those found in adult female kidney. In addition, we found that the allelic ratio of Xist transcripts from reciprocal (XX) ES cell lines differentiating in vitro was identical to that of isogenic 10.5 to 11.5 day female embryos. These latter results suggest that there is no pattern of preferential paternal imprinting during days 1 to 9 of in vitro differentiation of ES cells. However, the influence of the Xce locus on the randomness of X-inactivation in embryos seems to operate also in ES cell lines. Our overall conclusion is that the low levels of Xist RNA in female kidney, embryos and differentiating (XX) ES cells are compatible only with models that do not require Xist RNA to cover the entire inactive X chromosome.

Is the risk of cancer increased in Asians living in the UK?

The pattern of cancer in white and Asian (Indian, Pakistani, and Bangladeshi) children living in the West Midlands Health Authority Region was investigated using age standardised incidence rates. Two sets of rates were calculated, a 10 year rate (1982-91) using survey based estimates of the ethnic population and a four year rate (1989-92) using the ethnic population counts from the 1991 census. The 10 year rates showed a significantly higher annual incidence of cancer in Asian (159.1/million/year) than in white (130.8) children. The pattern of cancers in Asian children was different, with an excess of lymphomas and germ cell tumours, and a deficit of rhabdomyosarcomas. These findings were confirmed by the four year rates. Although underestimation of the Asian population probably contributes to the apparent excess, there remains cause for concern that UK Asian children may be at higher risk of cancer. Accurate ethnic population figures and confirmatory studies are urgently required.

Hodgkin's disease in children in the West Midlands, 1957-1986: a large population-based study

One hundred forty-one children were diagnosed with Hodgkin's disease between 1957 and 1986 in the West Midlands Health Authority Region (1991 population, 1.1 million children). Eighty-seven were boys and 54 were girls, representing a significant male:female ratio of 1.5:1 (P < 0.01). The average age-standardized incidence rate was 3.6 per million per year with a significant increase in the older age group (> or = 10 years) in the second half of the period (P = 0.02). The mixed cellularity subtype was more common in those younger than 10 years, with nodular sclerosing disease being seen more in those < or = 10 years. Overall survival at 5 years was 76% (65% at 10 years) with a significant difference (P < 0.001) in survival between the first and last decades. There was six second malignancies, five of which could have been treatment related. A positive history of cancer in close relatives was found in 11 patients, and higher social class was found in more older than younger children. These findings support the hypothesis that Hodgkin's disease may have a viral etiology and may be linked with socioeconomic conditions.

Thirty years of retinoblastoma (1960-89): changing patterns of incidence

This study of a 30-year population-based dataset investigates further an earlier observation that the incidence of sporadic bilateral retinoblastoma appeared to be increasing in recent years in the West Midlands Health Authority Region (WMHAR). Stringent measures were applied to ensure complete ascertainment of all cases of retinoblastoma in children in the region, resulting in a total of 117 cases diagnosed during the period 1960-89 in the WMHAR. Hospital case notes were abstracted and follow-up data obtained. Incidence rates were calculated. The overall incidence remained constant over the 30-year period, but that of sporadic bilateral tumours increased, with a corresponding decline in familial cases. There was a statistically significant excess seen in Asian children.

DNA ploidy and proliferative activity (S-phase) in childhood soft-tissue sarcomas: their value as prognostic indicators

The value of DNA ploidy as a prognostic indicator is well established in many cancers, but recent studies in childhood rhabdomyosarcoma (RMS) have been contradictory. In a retrospective study of 128 cases of soft-tissue sarcoma (STS) diagnosed since 1980, the prognostic value of clinical, histological and flow cytometric parameters was compared, using univariate and multivariate methods. Eighty-one RMSs, 18 extraosseous Ewing's (EOE)/peripheral neuroectodermal tumours (PNETs) and 29 other non-RMS STSs were histologically and clinically reviewed. Five year actuarial survival was 63.4% for all STSs and 69.4% for RMSs. Paraffin-embedded tissue blocks were available for flow cytometry in 90 cases. Of the RMSs, 65.5% were aneuploid [DNA index (DI) > 1.1] compared with 23% of the EOE/PNETs and 31% of non-RMS STSs. Median S-phase was also significantly higher in RMSs (17.0%) than in other STSs (10.8%) (P = 0.0023). Univariate analysis in RMSs showed that stage, ploidy status, S-phase, site and tumour size all had a significant impact on survival. In multivariate analysis of 59 cases of RMS, one clinical and two flow cytometric parameters were independently associated with poor prognosis. These were stage (IV), nonhyperdiploidy (DI < 1.10 and > 1.8) and a high rate of proliferative activity (S-phase > 14.0%). These results confirm that ploidy and S-phase are important new prognostic indicators in rhabdomyosarcoma.

Expression and methylation of imprinted genes during in vitro differentiation of mouse parthenogenetic and androgenetic embryonic stem cell lines

Messenger RNA and methylation levels of four imprinted genes, H19, Igf2r, Igf-2 and Snrpn were examined by northern and Southern blotting in mouse parthenogenetic, androgenetic and normal or wild-type embryonic stem cell lines during their differentiation in vitro as embryoid bodies. In most instances, mRNA levels in parthenogenetic and androgenetic embryoid bodies differed from wild type as expected from previously determined patterns of monoallelic expression in midgestation embryos and at later stages of development. These findings implicate aberrant mRNA levels of these genes in the abnormal development of parthenogenetic and androgenetic embryos and chimeras. Whereas complete silence of one of the parental alleles has previously been observed in vivo, we detected some mRNA in the corresponding embryonic stem cell line. This ‘leakage’ phenomenon could be explained by partial erasure, bypass or override of imprints, or could represent the actual activity status at very early stages of development. The mRNA levels of H19, Igf2r and Igf-2 and the degree of methylation at specific associated sequences were correlated according to previous studies in embryos, and thereby are consistent with suggestions that the methylation might play a role in controlling transcription of these genes. Paternal-specific methylation of the H19 promoter region is absent in sperm, yet we observed its presence in undifferentiated androgenetic embryonic stem cells, or before the potential expression phase of this gene in embryoid bodies. As such methylation is likely to invoke a repressive effect, this finding raises the possibility that it is part of the imprinting mechanism of H19, taking the form of a secondary imprint or postfertilization epigenetic modification necessary for repression of the paternal allele.

Recurrent hemangiopericytoma of the chest wall: report of a case in a 5-year-old boy

Hemangiopericytoma in infants and children is usually benign. A case of recurrent hemangiopericytoma of the mediastinum in a 5-year-old boy is reported. The tumor recurred twice because of incomplete excision in the first instance. Immunohistochemistry of this enigmatic tumor is reviewed and ultrastructural features are described. The importance of total initial excision of the tumor and a prolonged follow-up is highlighted.

Retrospective study of prognostic value of DNA ploidy and proliferative activity in neuroblastoma

AIM

To assess the prognostic value of age and stage at diagnosis, site of primary tumour, cell ploidy and N-myc copy number in children with neuroblastoma.

METHODS

Flow cytometry was used to determine the cellular DNA content of paraffin wax embedded archival material from 69 cases of neuroblastoma and was successful in 52.

RESULTS

The age, stage, and survival distribution of the sampled cases was not significantly different from that in a larger population based series. There were seven diploid ("non-aneuploid") and 45 aneuploid (including two tetraploid and four triploid) tumours. The 10 year survival was significantly better for cases of aneuploid rather than diploid tumours (p < 0.05). An important new finding was that 10 year survival was also significantly better for tumours with a low percentage of cells in S phase (p < 0.03).

CONCLUSION

The percentage of cells in S phase, a measure of the proliferative activity of the tumour, correlated with prognosis in neuroblastoma. This should be measured with other biological features of the disease, such as N-myc copy number, when prognostic indicators are being assessed.

Congenital abnormalities in children with cancer and their relatives: results from a case-control study (IRESCC)

Several studies have revealed an excess of malformations in children with certain malignancies. A few environmental causes have been identified which may damage the foetus and lead to malformation and cancer. However, most of the numerous recognised cancer/malformation syndromes are genetically determined. This report describes a case-control study of 555 newly diagnosed children with cancer and 1,110 matched controls, chosen from general practitioner lists (GP controls) and hospital admissions (H controls). Their parents were interviewed on topics of possible aetiological significance and medical records were checked to confirm reports at interview. The numbers of congenital malformations in the index and GP control children, and the relatives of the index children, the GP and H controls are described. There were more children with malformations among the cases (60/555) than among the GP controls (27/555), P < 0.001. The abnormalities in the cases included eight with specific chromosomal/genetic conditions (e.g. Down's syndrome, XY gonadal dysgenesis, Von Recklinghausen's neurofibromatosis, Goldenhar's syndrome) whereas only one GP control child had a chromosomal defect (P < 0.05). Five case children but no GP controls had neural tube defects; this is not statistically significant. No excess of malformations was found in the siblings of cases compared with GP and H control siblings. Case mothers had a small excess of malformations (22/555) compared with GP controls (8/555), P < 0.05. Among more distant relatives the results were difficult to interpret because of the relatively small numbers in the diagnostic subgroups and because of apparent under reporting in grandparents, but no striking differences were seen between case and control relatives. The excess of malformations found in children with cancer, compared with controls, without a similar excess of malformations in their close relatives may indicate that in some (perhaps very roughly one in 20) cases antenatal events may lead both to the malformation and the malignancy.

Carcinoid tumours of the appendix in children 1957-1986: incidence, treatment and outcome

Forty carcinoid tumours of the appendix were identified in children under 15 years of age between 1957 and 1986 from the records of the West Midlands Regional Children's Tumour Research Group. A significant excess of girls was observed (P = 0.02). All tumours were discovered incidentally and two patients underwent further surgery. Twenty-two of the 29 confirmed locations (76 per cent) were at the tip of the appendix and 34 of the 40 tumours (85 per cent) had invaded beyond the appendiceal submucosa. The reported incidence rate of 1.14 per million children per year remained constant throughout the study period. No recurrences, metastases or deaths from tumour were detected. Appendicectomy alone is confirmed as usually curative, although right hemicolectomy is occasionally necessary. Caution during routine appendicectomy is recommended to avoid possible tumour damage, as is consistent histological examination of all appendices in the paediatric age group. The importance of long-term follow-up is emphasized.