Estimating the Population Burden of Injuries

BACKGROUND

Injuries represent an important public health problem but their incidence is difficult to estimate.

METHODS

We conducted a population-based household survey in Greece covering 4079 interviewed individuals. The interviewees reported, for themselves and for cohabitating adults (age 15 years and older; n = 7157), injuries that occurred during the preceding year. Major injuries were defined as those requiring contact with a health institution. We compared these survey data with data obtained through a national Emergency Department Injury Surveillance System (EDISS).

RESULTS

For the month closest to the survey interview, the incidence reported for the responders was 5.9 per 100 person-year, whereas the incidence for cohabitating adults was 3.7 per 100 person-years. These incidence rates declined for months more remote to the interview. Comparison of survey and EDISS data suggested that survey reporting was less accurate for nontraffic-related injuries. Taking into account possible recall and telescoping biases, the best survey estimate of the national annual number of major injuries is 525,000 (5.9 per 100 person-year), whereas the EDISS data yielded an estimate of 1,150,000 major injuries (12.9 per 100 person-years)

CONCLUSIONS

Comparison of survey and EDISS data systems provides quantitative assessment of accuracy of the survey data in relation to time of injury before report date, to severity of injury, and to whether the injury is to the interviewee or to a cohabitant. The 2 systems could be used in a complementary way, although EDISS generates information that is medically more accurate and is a more cost-effective data collection system.

Identification of fetal nucleated red blood cells in the maternal circulation during pregnancy using anti-hemoglobin-epsilon antibody

AIM

To investigate the use of anti-hemoglobin-epsilon antibody in order to identify fetal cells in the maternal circulation during pregnancy.

MATERIALS AND METHODS

48 blood samples were obtained from pregnant women, 26 in the 1st trimester and 22 in the 2nd trimester. Magnetic activated cell sorting was used for fetal cell enrichment followed by immunophenotyping with a monoclonal antibody against hemoglobin-epsilon. FISH with X, Y and 21 chromosome-specific probes was performed in 29 cases.

RESULTS

The mean number of epsilon-positive cells was 9.2 (range 2-23) in the 1st trimester, 4.8 (range 3-13) in the 2nd trimester and 22 (range 15-28) in pregnancies with Down syndrome. No significant difference was noted in the number of epsilon-positive nucleated red blood cells (NRBCs) isolated from carriers and noncarriers of beta-thalassemia. FISH analysis was successful in 24 cases. In 4 cases with known male fetuses, an average of 4.7 epsilon-positive cells showed a Y signal. In 4 cases with Down syndrome, all epsilon-positive cells showed 3 signals for chromosome 21.

CONCLUSION

Anti-hemoglobin-epsilon antibody has increased specificity for fetal NRBCs and should be preferentially used to improve noninvasive prenatal diagnosis of chromosome abnormalities from fetal cells in maternal blood.

Efficiency of interphase fluorescence in situ hybridization for BCR/ABL on peripheral blood smears for monitoring of CML patients: a comparison with bone marrow findings

Conventional cytogenetic analysis (CCA) is the standard method for monitoring of the Philadelphia (Ph) chromosome in chronic myeloid leukemia (CML). Evaluation of breakpoint cluster region/abelson murine leukemia (BCR/ABL) fusion using interphase fluorescence in situ hybridization on peripheral blood smears (PB-FISH) might be another approach allowing more frequent and less invasive follow-up investigations. Herein, BCR/ABL fusion gene was assessed on 21 PB smears from 16 CML patients in chronic phase. Results of PB-FISH were compared with those of CCA and interphase FISH on bone marrow aspirates (BM-FISH). PB-FISH analysis was combined with CD3 immunophenotyping that allowed simultaneous investigation of the leukemic status of CD3(+) T lymphocytes and scoring CD3(-) cells for BCR/ABL fusion gene. Moreover, the frequency of BCR/ABL fusion in nonlymphoid PB cells was estimated according to the differential leukocyte counts. The incidence of BCR/ABL(+) fusion signals in CD3(+) T cells of CML patients was 5.3% (SD +/- 1.9) and did not exceed the normal cut-off value of 8%. A significant correlation (P < 0.001) was found between results of PB-FISH and methods of BM analysis (CCA or BM-FISH). Correction of PB-FISH results to include only nonlymphoid or CD3(-) cells reduced the mean of differences and improved agreement between PB-FISH and CCA or BM-FISH methods. The best agreement was noted between CCA and PB-FISH on nonlymphoid cells. On the other hand, results of BM-FISH agreed well with those of PB-FISH on CD3(-) cells. These findings imply that PB-FISH on nonlymphoid or CD3(-) cells is reliable and may replace BM analysis for monitoring of response to treatment in CML patients.

Use of annexin V antibody to identify apoptotic cells during pregnancy

In a previous study, we demonstrated that apoptosis increased according to gestational age, accounting partly for the presence of free fetal DNA in maternal plasma and serum. Using simultaneous TUNEL assay and FISH analysis, we identified the fetal origin of part of the apoptotic cell population, but very few TUNEL-positive cells showed hybridization signals since they were in a late apoptosis stage and nuclei were destroyed. In the present study, the apoptotic cell population was identified immunocytochemically using Annexin V, a marker of cells in an early stage of apoptosis. The mean apoptosis rate in mononuclear cells isolated from the peripheral blood of 20 pregnant women in the 16th to 19th week of pregnancy with Annexin V was 6.8 +/- 0.5% (range: 4.2-8.1%) compared to 6.14 +/- 0.5% (range: 3.7-6.9%) obtained with ethidium bromide staining. FISH using X and Y chromosome-specific probes was applied in 11 cases known to be carrying male fetuses. Eighty percent of Annexin V+ cells showed hybridization signals, while the proportion of apoptotic cells showing X/Y signals was 7.8% (range: 5-12%). Although our results are still preliminary, it seems that use of Annexin V antibody to detect the apoptotic cell population improves FISH analysis and allows a more accurate estimate of the proportion of fetal cells among the apoptotic cell population.

Detection of fetal NRBCs in maternal blood of pregnant carriers of beta-thalassemia using anti-gamma and anti-epsilon monoclonal antibodies

Fetal nucleated red blood cells (NRBCs) entering maternal circulation during pregnancy constitute a potential source of material for safe and reliable noninvasive prenatal diagnosis. The increased prevalence of beta-thalassemia mutations in countries like Greece may create a problem, making it difficult to distinguish between NRBCs of fetal or maternal origin. Use of Ab against embryonic hemoglobin epsilon may increase specificity for fetal NRBC detection. In the present study, Ab against embryonic hemoglobin epsilon was used in the first and second trimesters of pregnancy in order to determine if specificity for fetal NRBC detection could be increased.

Apoptosis in maternal peripheral blood during pregnancy

OBJECTIVE

To investigate the mononuclear cell apoptosis rate during pregnancy.

MATERIALS AND METHODS

Apoptosis was quantitated by EtBr staining in whole peripheral blood samples of 135 women in different gestational weeks and 85 nonpregnant women used as controls. Apoptosis was also qualitated by TUNEL assay.

RESULTS

The apoptosis rate increased during pregnancy according to gestational age. In chromosomally abnormal fetuses apoptosis was 2.5-fold higher than that found in pregnancies with normal embryos matched for gestational age. FISH in TUNEL-positive cells using X, Y and 21 chromosome probes verified the fetal origin of part of the apoptotic population.

CONCLUSION

Apoptosis is stimulated in maternal peripheral blood during pregnancy, possibly accounting partly for the presence of free fetal DNA in maternal serum. The increased apoptosis rate in pregnancies with chromosomally abnormal fetuses may have additional clinical importance.

Evaluation at single cell level of residual Philadelphia negative hemopoietic stem cells in chronic phase CML patients

In chronic myeloid leukemia, accurate determination of Ph(-) Hemopoietic stem cells (HSC) in peripheral blood (PB), bone marrow (BM) and leukapheresis products is important for the selection of patients for whom mobilization, collection, and autografting of Ph(-) HSC are envisaged. To this effect, the BCR/ABL fusion was assessed at the single cell level in 25 sets of PB and BM samples using dual-color I-FISH in immunophenotyped CD34(+) cells and RT-PCR of individual CFU-GM colonies. In 15 cases found to be 100% Ph(+), the respective BCR/ABL gene was absent in 30% of CD34(+) cells, while the respective transcripts could not be identified in 17% of CFU-GM. The mean percentage of BCR/ABL(-) CD34(+) cells and CFU-GM cells was higher (38% and 29%, respectively) in untreated patients than in treated patients (24% and 7%, respectively). In eight cases with cytogenetic response (CgR), the percentage of Ph(-) metaphases correlated with the level of BCR/ABL(-) colonies in BM and PB and with the proportion of BCR/ABL(-) CD34(+) cells in the BM. Immunophenotyping and FISH was fast, easy, always informative, and quantitative for the BCR/ABL(-) CD34(+) cells. Our results show that (a) at early diagnosis a high frequency of BCR/ABL(-) HSC circulate in the PB and that Ph(-) hematopoiesis is not completely suppressed; (b) although normal clonogenic cells decline rapidly within a few months after diagnosis, appreciable numbers of normal CD34(+) cells survive in chronic phase, especially in patients with CgR.

Identification of three polymorphisms in the dystrophin gene

Three polymorphisms were identified in the dystrophin gene using the polymerase chain reaction (PCR) and single strand conformation analysis (SSCA). Two of them (in intron 3) were reported for the first time while the third (in intron 43) is of interest as it is found mostly in patients with a recombination event in the same region.

Improved specificity of NRBC detection in chorionic villus sample supernatant fluids using anti-zeta and anti-epsilon monoclonal antibodies

OBJECTIVE

Fetal erythrocytes leak from fetal capillaries at the time of chorionic villus sampling (CVS). It has been reported that in approximately 60% of CVS cases fetal nucleated red blood cells (NRBC) can be isolated from the supernatant fluid by immunophenotyping with monoclonal antibody (Ab) against the gamma-chain of fetal hemoglobin and used as an additional source for confirmation of the fetal karyotype. However, the increased prevalence of beta-thalassemia mutations in countries such as Greece results in many pregnant women who produce gamma-positive cells. This makes it difficult to distinguish between the fetal and maternal origin of the NRBC. Use of Abs against embryonic hemoglobin chains zeta and epsilon may increase specificity for fetal NRBC detection.

METHODS

Mouse monoclonal Abs against Hb-zeta and Hb-epsilon were used in order to examine if specificity for fetal NRBC detection in CVS supernatant fluids could be improved. 41 samples were studied using anti-zeta and 20 using anti-epsilon monoclonal Abs.

RESULTS

Anti-zeta or anti-epsilon positive erythrocytes were, respectively, identified in 52 of 61 CVS samples and anti-zeta or anti-epsilon positive NRBC were present in all cases. The mean number of Hb-positive erythrocytes identified with the anti-zeta Ab was 58 and the mean number of NRBC 29. The mean number of anti-epsilon positive erythrocytes was 30 and of NRBC 23. FISH with X and Y chromosome specific probes was performed in 26 cases and the results were concordant with the CVS karyotype. Statistical analysis using the correlation test showed that anti-zeta and anti-epsilon were more specific for the detection of embryonic NRBCs.

CONCLUSIONS

Since embryonic monoclonal Abs show increased specificity, they should be preferentially used for NRBC detection in CVS supernatant fluids. Furthermore, the increased specificity of anti-zeta and anti-epsilon Abs may considerably improve prenatal diagnosis from fetal cells isolated from maternal circulation.

Screening for minor changes in the distal part of the human dystrophin gene in Greek DMD/BMD patients

The distal part of the human dystrophin gene is characterised by particular features and seems to play an important functional role. Additionally in recent years several data have implicated minor mutations in this gene region in some patients with mental retardation (MR). In order to screen for pathogenic mutations at the distal part of the human dystrophin gene we have used single-strand conformation analysis of products amplified by polymerase chain reaction (PCR-SSCA) in 35 unrelated male Greek DMD/BMD patients with no detectable deletions. Seven patients also had severe mental retardation. Direct sequencing of samples demonstrating a shift of SSCA mobility revealed six different and pathogenic minor changes, five in DMD and one in a BMD patient. Four of the mutations were found in DMD patients with severe MR. Three of these mutations were localised in exon 66, which presents an interesting similarity with part of the 3' end of the genome of eastern equine encephalomyelitis virus (EEEV). The present data from Greek DMD/BMD patients give further information about the phenotypic effects consequent on mutations in exons at the distal part of the human dystrophin gene.

Chromosome fragility and predisposition to childhood malignancies

In order to clarify the possible connection between autosomal folate sensitive Fragile Sites (FS) and genetic susceptibility to haemopoetic disease in children we investigated the frequency and distribution of FS in the Peripheral Blood Lymphocytes (PBL) of 56 children with newly diagnosed and untreated haematologic malignancies and their parents. The incidence was compared with that of 146 normal controls (children and adults). In all patients the Bone Marrow (BM) karyotype was also determined. Heritable FS were detected in 49 patients (87.5%). 20 children had more than one FS and in all cases it was inherited from one of their parents, although there was a significant excess of transmitting mothers. 19 different FS were identified: 14 common, 4 rare and one, 22q11, which has not been previously reported, but it is considered as important as it coincides with the cancer breakpoint resulting in the formation of the Philadelphia (Ph) chromosome. The frequency of FS in the PBL of the patients was significantly higher than in the controls and this increase was independent of any abnormality detected in the malignant cells of the BM. However, patients with an abnormal BM karyotype displayed increased frequency of FS induction as compared to patients with a normal karyotype. In three cases the heritable FS was found to be at or near the breakpoints of the chromosomal rearrangements detected in the malignant cells. The findings are discussed with regard to cancer specific breakpoints, oncogene loci and sites where viral DNA can be inserted to the genome. The results of this study suggest that autosomal folate sensitive FS may increase the risk for haematologic malignancies through a complex mechanism which remains to be clarified.

The growth pattern and final height of girls with Turner syndrome with and without human growth hormone treatment

BACKGROUND

Shortness is the most frequent and quite disturbing characteristic of girls with Turner syndrome (TS). Human growth hormone administration (hGH) to girls with TS increases growth velocity (GV), but a favorable effect on final height (FH) has not been documented. The aim of this study was to evaluate the effect of hGH administration on the growth pattern and FH in girls with TS.

METHODS

The study group was comprised of 123 girls with TS who were cared for in our center. Eighty-two of these girls received hGH (mean dose, 0.78 +/- 0.12 IU/kg/week), given subcutaneously 5 to 7 times per week for a period of 2.2 +/- 1.2 years (hGH group). The mean chronological age (CA) and bone age (BA) at hGH initiation were 11.5 +/- 2.5 years and 9.7 +/- 2.3 years, respectively. The remaining 41 girls did not receive hGH and are designated as the untreated control group. In both groups, gonadal steroids were given for pubertal initiation and maintenance.

RESULTS

The GV during the first year of hGH therapy (GV1) was higher than the year before hGH (6.3 cm/year vs 4.0 cm/year) and higher than the GV of the untreated group at a similar CA (4.4 cm/year). The GVs during the second (GV2) and third (GV3) year of hGH treatment (5.4 and 4.9 cm/year, respectively) were lower, but still higher in the hGH group, in comparison with the untreated group (GV2, 4.2 cm/year; GV3, 3.4 cm/year). GV1, GV2, and GV3 were negatively related to age and to BA at hGH initiation. The FH of the 35 hGH-treated girls was not significantly different from the FH of the 27 untreated girls (146.1 cm vs 144.0 cm). The Delta target height-FH was not significantly different in the two groups. The FH standard deviation score of the hGH-treated group was positively related to height standard deviation score for CA at treatment initiation (r = +0.73), maternal height (r = +0.57), target height (r = + 0.66), and birth weight (r = +0.54), but was unrelated to CA or BA at start of therapy or to hGH dose.

CONCLUSIONS

hGH therapy in girls with TS, in the dose and duration of treatment applied in this study, significantly accelerated GV but did not significantly improve FH.

Awareness and use of prenatal diagnosis among Greek women: a national survey

The prevention of genetic diseases through prenatal diagnosis depends to a large extent on the awareness and acceptance of available methods by the public. A national survey was conducted among Greek women in order to explore their attitudes towards and their use of prenatal diagnosis in relation to their lifestyle. The survey was originally addressed to 3000 Greek women 18-65 years of age. Using as a criterion having a child 5 years old or younger, 350 women were eligible for the study. It was noted that 52 per cent of the respondents were adequately informed, while 48 per cent had either superficial knowledge of the subject or no knowledge at all. Amniocentesis was the method that most women were familiar with. The majority said that they were informed by their doctors and the media, and 13 per cent of the participants had prenatal diagnosis during a previous pregnancy. Twenty-two per cent of those who were not tested were over 35 years of age at the time of pregnancy. There was a significant positive correlation between awareness and acceptance of prenatal diagnosis, on the one hand, and the social, educational and financial profile of the women, on the other. Women aware of prenatal diagnosis adhered more closely to a healthy lifestyle and lived a family-centred life.

Fetal cells in maternal blood: isolation by magnetic cell sorting and confirmation by immunophenotyping and FISH

Fetal cells entering the maternal circulation during pregnancy constitute a potential source for safe and reliable non invasive prenatal diagnosis. However, selecting the appropriate fetal cell type and methods of enrichment are areas of paramount importance. Most investigators consider fetal nucleated red blood cells (NRBCs) to be the cell type of choice, since they are mononuclear, abundant in fetal blood, relatively well differentiated and have a limited life span. Twenty ml of peripheral blood samples were collected from 40 pregnant women in the 16th to 18th week of pregnancy. To enrich for NRBCs, found within an excess of maternal cells, negative magnetic cell sorting (MACS) was used. Leukocytes were depleted from maternal blood by treatment with anti CD45 monoclonal antibody, as this surface antigen is not expressed in NRBCs. NRBCs were detected in 35 of the 40 maternal samples with May Grunwald-Giemsa staining. In 30 cases UCH gamma positive cells were identified after immunophenotyping with a monoclonal antibody directed against the gamma chain of fetal hemoglobin. The mean number of isolated NRBCs was 6 (range 1-15). In 5 cases we were able to successfully perform FISH on the immunophenotyped cells and determine correctly the fetal gender using X and Y chromosome specific probes.

Fetal nucleated erythrocytes (NRBCs) in chorionic villus sample supernatant fluids: an additional source of fetal material for karyotype confirmation

Fetal erythrocytes leak from the fetal capillaries at the time of chorionic villus removal. The purpose of this study was to determine if fetal nucleated erythrocytes (NRBCs) could be isolated from the chorionic villus sampling (CVS) supernatant fluid and used as an additional source of fetal material in order to confirm the fetal karyotype in cases of CVS mosaicism. One hundred CVS supernatant fluids were studied by simultaneous immunophenotyping, using a mouse antifetal haemoglobin antibody, UCH gamma, combined with fluorescent in situ hybridization (FISH) analysis using X- and Y-specific DNA probes. A chromosome 18 probe was also used in the case of a known male fetus with trisomy 18. Fetal haemoglobin (HbF)-positive cells were identified in 73 supernatant fluids and HbF-positive nucleated cells were present in 60 samples. The number of cells detected per sample showed great variation among the individual samples. FISH analysis was performed in 41 cases. FISH prediction of the fetal gender was concordant with the CVS karyotype in all cases, and the fetal trisomy 18 was correctly verified. In five cases in which Y sequences were detected, a small number of HbF-positive cells with two X signals were also identified; interestingly, in three of the five cases, the mother was a beta-thalassaemia carrier. This technique can be used as a quick and accurate method for the immediate verification of CVS results in cases of mosaicism, thus avoiding second-trimester amniocentesis.

Prenatal diagnosis services in Greece

The report presents the available prenatal diagnosis (PND) services in Greece. PND for chromosomal anomalies after amniocentesis was initiated in 1976 and became gradually widely accepted. Chorionic villus sampling was introduced in 1983. Approximately 6,500 women undergo PND for chromosomal anomalies annually, most of them for advanced maternal age. 700 cases are also tested prenatally each year for haemoglobinopathies. The study describes the PND services available in the country, the procedures currently used, the impact of prenatal testing on the prevention of genetic diseases and the legal issues concerning PND in Greece.

Secondary malignancies in a child with Hodgkin's disease: T-cell lymphoma and myelodysplastic syndrome evolving into acute nonlymphoblastic leukaemia

Hodgkin's disease (HD) has been linked to an increase risk of second malignant neoplasms (SMN), especially non-Hodgkin's lymphoma (NHL) and acute nonlymphoblastic leukaemia (ANLL). The mutagenic property of cytotoxic therapy as well as defective immunity have been implicated as playing a major role in the development of SMN in patients previously treated for HD. We report a case of a 14-year-old girl with HD who developed two different second malignancies within a latent period of 28 months following HD diagnosis. The patient presented initially with bilateral cervical and supraclavicular as well as mediastinal and paraaortic lymphadenopathy. She was staged as IIIA, nodular sclerosing type HD, and was given eight alternative cycles of MOPP-ABVD followed by "mantle" field radiotherapy to a total dose of 3.3 Gy plus 0.4 Gy to the upper mediastinum. Within 8 months following the completion of therapy, a period of myelodysplasia and progressive severe immune deficiency, considered as a result of initial treatment, occurred. Eighteen months after HD diagnosis while the patient was continuously neutropenic and heavily immunocompromised, a peripheral T-cell lymphoma of the angiocentric immunoproliferative lesion type (AIL) Grade III, appeared in both lungs within and beyond the radiation field, with no evidence of HD in biopsy specimens. After institution of a new chemotherapy regimen (L17M), a satisfactory response regarding NHL lesions was noted. However, 10 months later the myelodysplastic syndrome (MDS) accompanied by complex chromosomal abnormalities evoluted to frank ANLL with a rapid fatal course. This case supports the hypothesis that combined modality treatment accompanied by severe immunodeficiency may result in the development of multiple second malignancies even within a very short latent period, especially in a subgroup of HD patients who may be particularly increased risk of second cancers.

Mapping dystrophin gene recombinants in Greek DMD/BMD families: low recombination frequencies in the STR region

A systematic study of 42 Greek DMD/BMD families using 14 polymorphic markers that span the dystrophin gene was performed in order to assess the position and frequency of recombinants in the Greek population and to test whether "hot spots" of recombination and deletions coincide when exclusively studying DMD/BMD families. We report a low percentage of recombination between markers STR44 and STR50; otherwise, the distribution of recombination events in other parts of the gene is largely in agreement with previously published data on Centre d'Etude du Polymorphisme Humaine families. We therefore propose that recombination frequencies and the correlation between recombination and deletion "hot spots" should be evaluated on DMD/BMD families exclusively.

Deletion patterns of Duchenne and Becker muscular dystrophies in Greece

We present molecular data from 90 Greek boys with Duchenne or Becker muscular dystrophy using cDNA analysis or multiplex PCR or both. Deletions were detected in 63.3% of patients and were mainly clustered in two areas of the gene, one in the 3' and one in the 5' end of the gene (exons 3-19 and 44-53). Almost 17% of deletion breakpoints lay in intron 44 while 29% of deletions have a breakpoint in intron 50. Thus the distribution of deletions in our DMD/BMD patients differs from that previously reported. Furthermore a 1:4.35 proximal:distal ratio was observed in familial cases and a 1:2.45 ratio in isolated ones.

Longitudinal changes in IQ among fragile X males: clinical evidence of more than one mutation?

Longitudinal changes in IQ among mentally retarded (MR) fragile X [fra(x)] males have been reported previously. While age is associated with decline in IQ, not all males are so affected. This suggests that there may be more than one subtype of affected fra(X) male. Therefore, we examined the distribution of standardized difference scores (Zdiff) in IQ to determine if subjects were from an admixture of at least 2 populations. Cluster analysis of Zdiff scores was used to partition subjects into 2 groups. Goodness-of-fit tests indicated that scores were more likely to come from an admixture. Discriminant functions (DF) were calculated to determine predictive validity of Zdiff scores. To eliminate the effect of skewing, a power transform was applied to Zdiff scores and DFs recomputed. Zdiff and transformed scores provided similar results. The mean and variance for one group showed no differences in test-retest scores as would be expected from examining any population while the mean for the second group indicated significant decline in IQ nearly 4 standard errors below the first test score. These results suggest that there may be clinical evidence for 2 types of fra(X) mutation: One which causes MR but is static, and a second mutation which causes MR but is dynamic and contributes to an apparent longitudinal decline in cognitive function.

Autosomal folate sensitive fragile sites in normal and mentally retarded individuals in Greece

The frequencies of autosomal folate sensitive fragile sites were compared in populations of mentally retarded fra(X) negative (N = 220) and normal children (N = 76) in Greece. In addition, the frequency of autosomal fragile sites was studied in 20 known fra(X) children in order to test if the fra(X) syndrome is associated with general chromosome instability. The frequencies of both common and rare autosomal fragile sites did not differ significantly between the mentally retarded and the normal children, although the rate of expression was considerably higher in the retarded group. Autosomal fragile sites were not increased in the fra(X) patients. Fra(3)(p14) was by far the most frequent one in all groups. The frequency of fra(6)(q26) was found to be considerably higher among the mentally retarded children, this difference being almost statistically significant. Further cytogenetic studies of normal and retarded individuals are required in order to elucidate this point further.

Laband syndrome: a case report

A case of Laband syndrome in an 8-yr-old girl is presented. The case is sporadic. The patient manifests enlargement of the soft tissue of the hard palate and the gingiva, which partly or completely covers the crowns of the teeth and macroglossia. The cartilagenous part of the nose and the ears is large and soft. She has synophrys and thick, straight hair. The nails of the fingers and toes are dysplastic. The girl exhibits no other abnormality, except an IQ of 61.

Martin-Bell syndrome in Greece, with report of another 47,XXY fragile X patient

A cytogenetic investigation was carried out among 200 mentally retarded boys in Greece for the detection of the fragile X [fra(X)] syndrome. Thirteen patients were found to carry fra(X) (6.5%). Of those, six boys had a history of familial X-linked mental retardation, two had the phenotype of the Martin-Bell syndrome, four had only mental retardation of unknown etiology, and one was a mentally retarded patient with Klinefelter syndrome. The remaining 187 boys were fra(X) negative. Our findings emphasize the importance of early identification of this syndrome in the diagnosis and prevention, through proper genetic counselling, of mental retardation.

Prenatal diagnosis of chromosomal abnormalities from chorionic biopsy samples: improved success rate using a modified direct method

Several methods for fetal chromosome analysis using chorionic biopsy samples were compared. A modified direct method for culturing villi was considered to be the method of choice and details are presented of 186 pregnancies tested prenatally. The success rate in obtaining a fetal karyotype with the direct method was 93 per cent. The fetal loss rate in the prenatal series was 4.3 per cent and congenital abnormalities in the babies already born did not differ from the expected incidence.

A familial X/Y translocation in a boy with ichthyosis, hypogonadism and mental retardation

A 14-year-old boy is described with hypogonadism, ichthyosis and mental retardation. His karyotype was 46,Y, der(X),t(X;)(p22;q11). His mother's karyotype was 46,X,der(X),t(X;Y)(p22;q11). Thus the son is nullisomic for the region Xp22 leads to pter and the mother is monosomic for the same region. The steroid sulfatase activity in this boy is discussed in relationship to the enzyme's locus on the X chromosome and the manifestation of ichthyosis.