The mannose binding lectin gene influences the severity of chronic liver disease in cystic fibrosis.

Chronic liver disease is a major complication of cystic fibrosis. Its incidence and severity show marked heterogeneity, even among the homogeneous group of homozygous DeltaF508 patients, suggesting that environmental or genetic factors other than the deletion DeltaF508 may influence the development of cystic fibrosis related liver disease. We investigated whether the allelic variants of mannose binding lectin, an important protein of the immune system, could be associated with the presence of cirrhosis in a population of 216 homogeneous homozygous DeltaF508 patients. Analysis of the data shows that the presence of cirrhosis in cystic fibrosis patients is significantly associated with a mutated mannose binding lectin genotype (homozygous or compound heterozygous for mannose binding lectin variants). The modulating role of mannose binding lectin in the occurrence of cirrhosis in cystic fibrosis could be explained by the fact that hepatotoxic damage from viruses or bacteria might be increased by the immunodeficiency associated with mannose binding lectin variants and might facilitate the degradation of liver status. These data highlight the crucial role of mannose binding lectin in the clinical outcome of cystic fibrosis, as it has recently been shown that the mannose binding lectin gene is a modulating gene of the respiratory involvement in cystic fibrosis patients.

Whole blood serotonin and plasma beta-endorphin in autistic probands and their first-degree relatives.

BACKGROUND: Whole blood serotonin (5-HT) and C-terminally directed beta-endorphin protein immunoreactivity (C-ter-beta-EP-ir) are known to be elevated in autistic subjects and might be possible markers of genetic liability to autism. This study thus investigates the familial aggregation of 5-HT and of C-ter-beta-EP-ir levels in first degree relatives of autistic probands. METHODS: In a sample of 62 autistic subjects and 122 of their first-degree relatives, compared to age and sex-matched controls, we measured 5-HT by radioenzymology and C-ter-beta-EP-ir by radioimmunoassay. RESULTS: We confirm the previously reported familiality of hyperserotoninemia in autism as mothers (51%), fathers (45%) and siblings (87%) have elevated levels of 5-HT, and we reveal presence of elevated levels of C-ter-beta-EP-ir in mothers (53%) of autistic subjects. CONCLUSIONS: Familial aggregation of quantitative variables, such as concentration of neurotransmitters, within unaffected relative could serve as an intermediate phenotype and might thus help the search of genetic susceptibility factors in autism.

Indication of linkage and genetic heterogeneity of asthma according to age at onset on chromosome 7q in 107 French EGEA families.

It is generally believed that an early age at the onset of disease is associated with a stronger genetic component. Our aim here was to investigate both linkage and genetic heterogeneity of asthma, the latter corresponding to different genotype relative risks of a putative linked gene according to age at onset of asthma. This analysis was conducted in 107 French EGEA families with at least two asthmatic siblings, considering 157 markers that were part of our previous genome screen, using the TTS (the Triangle Test Statistic) which has been developed to detect both linkage and intra-sibpair genetic heterogeneity. This test has been applied to 38 asthmatic sib-pairs discordant for age at the onset of asthma. To confirm the existence of genetic heterogeneity, we also used the predivided sample test (PST) which compares the IBD (identity by descent) distribution of marker alleles between asthmatic sib-pairs concordant (67) and discordant (38) for the age at onset. The cutoff point used for the age at onset was 4 years, the median age at onset in our sample of asthmatic sibs. Linkage and genetic heterogeneity for a region located on chromosome 7q (at 109 cM from pter) were indicated by both tests, TTS (P=0.005, P>0.5 after correction for multiple testing) and PST (P=0.0001, 0.015 after correction). These results suggest a genetic factor on 7q involved in asthma with genotype relative risks differing according to age at onset of disease.

Genetic polymorphism of the mannose-binding protein gene in children with sickle cell disease: identification of three new variant alleles and relationship to infections.

Mannose-binding protein (MBP) is a serum lectin that participates in the innate immune response. MBP deficiency may constitute a risk factor in the development of infections. Three MBP structural variants have been identified with a dominant effect on MBP serum concentration. Similarly, polymorphisms in the promoter of the corresponding gene (HSMBP1B) have been related to variations of MBP concentration in serum. Children with sickle cell disease (SCD) have an increased susceptibility to infections with encapsulated organisms resulting in meningitis, septicaemia, and osteomyelitis. We have investigated the HSMBP1B genotype in 242 children with SCD living in Paris. Apart from the known variant alleles, we identified three novel ones and report their distribution in our sample population. In addition, we found rather unexpectedly an increased frequency of the variant alleles in patients who had not suffered severe infections.

Indication of linkage and genetic heterogeneity for asthma and atopy on chromosomes 8p and 12q in 107 French EGEA families.

Using the sample of 107 families with at least two asthmatic siblings, as part of the EGEA study, we have investigated linkage to asthma (or atopy) and genetic heterogeneity according to the presence/absence of atopy (or asthma) using two approaches: (1) the triangle test statistic (TTS), which considers the identical by descent (IBD) distribution among affected sib-pairs discordant for another associated phenotype (eg asthmatic sib-pairs discordant for atopy) and (2) the predivided sample test (PST), which compares the IBD distribution of marker alleles between affected sib-pairs concordant and discordant for the associated phenotype. Two regions, 8p and 12q, already reported to be linked to both asthma and atopy, were examined here. A total of 20 asthmatic sib-pairs discordant for atopy and 24 atopic pairs discordant for asthma were analyzed by both TTS and PST methods and 83 pairs with atopic asthma by PST. Some evidence for linkage was observed for two markers in the 8p23.3-p23.2 region; D8S504 for asthma with genetic heterogeneity according to the presence/absence of atopy and D8S503 for atopy with genetic heterogeneity according to the presence/absence of asthma. In the 12q14.2-q21.33 region, there was also some evidence of linkage to two markers, D12S83 and D12S95, for atopy and asthma, respectively, with genetic heterogeneity according to the presence/absence of the associated trait. Provided the small distance between the two markers on either 8p (16 cM) or 12q (21 cM), it is unclear whether one or two genetic factors are involved in either region.

Difference between plasma N- and C-terminally directed beta-endorphin immunoreactivity in infantile autism.

OBJECTIVE: The authors investigated whether there is excessive opioid activity in infantile autism by measuring plasma beta-endorphin in patients with autism compared with patients who had Rett's syndrome and normal comparison subjects. METHODS: Radioimmunoassays for beta-endorphin using C-terminally and N-terminally directed antisera were applied to plasma samples from 67 children who met both DSM-III-R and ICD-10 diagnostic criteria for infantile autism, 22 girls with Rett's syndrome, and 67 normal children matched in age and sex with the children with autism. RESULTS: Median N-terminally directed beta-endorphin immunoreactivity appeared to be slightly lower in subjects with autism (7 pg/ml) and clearly higher in the girls with Rett's syndrome (40 pg/ml) than in the comparison subjects (9 pg/ml). Median C-terminally directed beta-endorphin immunoreactivity was higher in the girls with Rett's syndrome (35 pg/ml) and much higher in patients with autism (70 pg/ml) than in comparison subjects (8 pg/ml). CONCLUSIONS: These findings demonstrate the existence of a wide discrepancy between C- and N-terminally directed beta-endorphin immunoreactivity among children with autism. Despite the fact that the nature of the antigen recognized in the plasma of autistic children by the C-terminally directed anti-beta-endorphin serum remains to be characterized, the difference between C- and N-terminally directed beta-endorphin immunoreactivity might suggest an abnormal processing of the pro-opiomelanocortin gene in infantile autism.

Adiposity indices in children.

On the basis of a longitudinal study of growth in French children, we attempted to find a valid index for estimating adiposity, and to specify the optimal conditions for its use. The Quetelet index was found suitable for application to children, but as with all methods, a certain lack of precision proved unavoidable because of the different stages of growth observed at a given age. For use by clinicians, we provide charts, based on the Quetelet index and on age, permitting estimation of adiposity in any child on the basis of longitudinal study measurements. For use by epidemiologists, we give standard values for studying groups of subjects, even when a reference population is not available. Body adiposity may be expressed independently of age and sex.

Adiposity rebound in children: a simple indicator for predicting obesity.

To follow and predict the evolution of adiposity during growth, individual adiposity curves, assessed by the weight/height2 index, were drawn for 151 children from the age of 1 month to 16 yr. Adiposity increases during the 1st yr and then decreases. A renewed rise, termed here the adiposity rebound, occurs at about 6 yr. Individual weight/height2 curves may differ regarding their percentile range level and age at adiposity rebound. The present study shows a relationship between the age at adiposity rebound and final adiposity. An early rebound (before 5.5 yr) is followed by a significantly higher adiposity level than a later rebound (after 7 yr). This phenomenon is observed whatever the subject's adiposity at 1 yr. The present observations might be connected with the cellularity of adipose tissue.

Exclusion of allelism of Noonan syndrome and neurofibromatosis-type 1 in a large family with Noonan syndrome-neurofibromatosis association.

A large four-generation family with Noonan syndrome (NS) and neurofibromatosis-type 1 (NF1) was studied for clinical association between the two diseases and for linkage analysis with polymorphic DNA markers of the NF1 region in 17q11.2. Nonrandom segregation between NS and NF1 phenotypes was observed. Neurofibromatosis was tightly linked to NF1 markers, whereas Noonan syndrome was found not be allelic to NF1. These results suggest that two mutations at two independent but closely linked loci are the cause of neurofibromatosis-Noonan syndrome (NF-NS) association in this family.

Patterns of familial aggregation of three melanoma risk factors: great number of naevi, light phototype and high degree of sun exposure.

BACKGROUND: Besides melanoma susceptibility genes and shared environmental exposures, part of the familial clustering of cutaneous malignant melanoma (CMM) might be due to familial aggregation of melanoma-associated phenotypes. Our goal was to assess the patterns of familial aggregation of three melanoma risk factors: great number of naevi (GNN), light phototype (LP) and high degree of sun exposure (HDSE). METHODS: Familial aggregation of GNN, LP and HDSE was investigated in 66 French families with at least two CMM cases and was measured by the asssociation of the relatives' traits with the probands' traits, using the generalized estimating equations approach. The probands were the melanoma cases leading to ascertainment of the families, subdivided into cases (with the trait studied) and controls (without the trait). RESULTS: We found significant evidence for familial aggregation of GNN only among sibs (OR = 3.7, 95% CI : 1.4-10.5, P = 0.01), of LP among blood relatives (OR = 3.8, 95% CI : 1.8-8.0, P = 0.004) and of HDSE among blood relatives (OR = 4.5, 95% CI : 2.1-9.9, P < 0.001) and spouses (OR = 44.3, 95% CI : 5.1-382.2, P < 10(-3)). These results suggest that genetic factors might account for the clustering of GNN and LP and shared environment for the aggregation of HDSE. The GNN clustering was lower in families with increasing numbers of CMM (>/=3 cases) or presence of p16 mutations, the opposite being observed for LP and HDSE. Moreover, the familial aggregation of LP was significantly lower in families with highly sun-exposed members. CONCLUSION: Melanoma might not only result from specific genetic and environmental factors but also from those underlying melanoma-associated traits involving complex gene-gene and gene-environment interactions.

Relationship between adiposity and food intake: an example of pseudo-contradictory results obtained in case-control versus between-populations studies.

Seemingly contradictory data support controversies concerning the relationships between food intake and illnesses. The present study of 1035 adults, aged 30-39 years, shows that (1) daily energy intake is not higher in obese than in non-obese people, (2) obesity is more prevalent in social groups where energy intake is higher. These pseudo-contradictory results can be reconciled on the basis of a constitution/environment interaction. A comparison of groups based on presence or absence of illness (obesity, hypertension, coronary heart disease (CHD), cancer, etc) shows that some people can develop risk factors, even though their feeding behaviour is normal. This result (no direct relationship) underlines differences in individual susceptibility. When comparisons are made between populations with different diets the results (direct relationship) express environmental factors. The hypotheses on behavioural contribution to the aetiology of certain diseases appears more clearly in between-population comparisons than in case-control studies. Results of comparisons between populations (if the hypotheses they suggest are confirmed by intervention studies) warrant prevention at the level of populations, while results of case-control studies justify particular prevention in subjects at risk.

Comparison between familial and nonfamilial melanoma in France.

BACKGROUND AND DESIGN: Five percent to 10% of cutaneous malignant melanomas (CMMs) occur in a familial setting. Clinical, epidemiologic, and genetic studies of familial CMM in different regions of the world have led to various results. To assess the characteristics of familial CMM in France, the clinical, histologic, and epidemiologic characteristics of 295 patients with CMM were recorded, and a comprehensive familial investigation was performed for each case. Patients with a family history of CMM were compared with nonfamilial cases. RESULTS: Cutaneous malignant melanoma occurred as a familial cancer in 22 (8%) of 295 patients. Among the multiple variables studied, those significantly associated with the familial occurrence of CMM were red hair, inability to tan, and presence of clinically atypical moles. When these variables were considered together in a multivariate analysis, only the association with red hair (P = .001) and atypical moles (P < .05) remained significant. In addition, the patients with familial melanoma exhibited the following tendencies: a younger age at diagnosis, a higher number of moles, and the development of multiple primary melanomas, but these results did not reach statistical significance. Factors relating to UV light exposure, histologic features of CMM, course of the disease, and occurrence of nonmelanoma cancers showed a similar distribution between familial and nonfamilial cases. CONCLUSION: A familial investigation should be performed for each patient with CMM in France, particularly when he or she exhibits phenotypic risk factors for CMM such as red hair and atypical moles.

Subtyping familial schizophrenia: reliability, concordance, and stability.

This report examines the reliability, concordance, and long-term stability of the subtypes of schizophrenia defined by four major diagnostic systems (DSM-III, DSM-III-R, ICD-10, and Tsuang-Winokur criteria) and rated both for the first hospitalization and for a best estimate diagnosis reflecting lifetime evolution of symptomatology. Schizophrenics studied belonged to two samples of multiply affected families, namely a sample selected in France and a sample of non-metropolitan French identified in the island of La Réunion. ICD-10 and DSM-III-R show opposite stringency regarding subtyping of schizophrenia, with DSM-III-R having a narrow and ICD-10 a broader definition of specific subtypes. Long-term stability of each subtype was fairly good, stability being the highest for hebephrenics and only intermediate for paranoid and undifferentiated subtypes. Comparison of two different cultural and geographical regions reveals an overall similarity of subtype frequencies in familial schizophrenia. The implications of the results for the choice of diagnostic procedures in family studies of schizophrenia are discussed.

Clinical subtypes and age at onset in schizophrenic siblings.

This study examines the concordance of clinical subtypes and age at onset of schizophrenia in 42 sibships of multiply affected schizophrenic patients. Subtypes were defined by four major diagnostic systems (DSM-III, DSM-III-R, ICD-10, and Tsuang-Winokur criteria) and rated both for the first hospitalization and long-term diagnosis. When a sibship method was used, no concordance for subtypes was found in siblings. Age at onset, analyzed as a continuous variable with the intraclass correlation method, was found to be correlated in siblings. This finding suggest that the search for continuous traits distributed in families of schizophrenic patients might constitute an alternative to discrete category-based family studies.

Implications of prenatal diagnosis of sickle cell disease.

Prenatal diagnosis (PND) of sickle cell disease (SCD) has been feasible since about 15 years. The number of PND performed for SCD has constantly increased during these years, but its availability raises difficult ethical questions for parents and counsellors. Concerning at-risk parents, only 50% (data in the literature) to 70% (personal data) ask for PND. Our study shows that mainly cultural reasons, then religious ones, educational level and the number of children in the family weigh on the parents' decision to request this diagnosis. The counsellors' position is difficult since clinical severity of the disease is highly variable, there is no early prognostic factor, and the median life expectancy of patients in industrialized countries exceeds 40 years. We need to define a counselling which would consider the image of the illness in the populations involved, in order to help parents understand the implications of the choice they are asked to make.

[Diet and rectocolonic cancers. Results of a case-control study]. / Alimentation et cancers recto-coliques. Résultats d'une étude "cas-témoin".

In a case-control study performed in an hospital of the North-Eastern Paris area, nutritional intakes of 94 patients with colorectal carcinoma were compared with those of 94 control patients, matched for age and sex. Results were expressed as mean daily nutrients and energy intakes. This dietary survey covered the "present period" (i.e. prior to the hospitalisation) and the "past-period" in case of striking and prolonged changes in dietary habits. Whatever the site of carcinoma (the rectum and sigmoid or the remaining colon) there was no statistically significant difference between patients and controls (in both sexes) for the following parameters: a) total energy intake, b) proportions of lipids, proteins and fat expressed as percentages of total energy intake, c) minerals, d) vitamins and e) dietary fibers. In women with colorectal carcinoma, a decrease in alcohol and lipid consumptions was observed. In patients with rectal or sigmoid carcinoma past alcoholic intakes were higher in both sexes. These results do not allow any clear epidemiological conclusion. In spite of their cost and length prospective studies are probably the only way to answer the difficult question of which dietary factors may be found in colorectal carcinoma.

[Food consumption in relation to size of collectivity. Parallel time trends (author's transl)]. / La consommation alimentaire des Français en fonction de la taille des agglomérations, reflet de l'évolution longitudinale.

The consumption of the French with respect to the size of parishes and its evolution from 1965 to 1974 can be investigated, thanks to the survey of Institut National de la Statistique et des Etudes Economiques on food consumption of a representative sample of households. During this period, with regard to the growing size of parishes and with respect to time, the percentage of lipidic calories has been raising, chiefly from the decrease in the consumption of vegetable foods which carries with it, at the same time, a decrease of the intake of glucids, dietary fibers and of the total energy intake. The shortcomings of data collecting explain only a small part of the discrepancies observed.

[Breast feeding effect relative to age of onset of celiac disease]. / Effets de l'allaitement maternel sur l'âge de début de la maladie coeliaque.

BACKGROUND: Age at onset and clinical presentation of celiac disease have often been related to the age of gluten introduction into the diet. It has also been shown that breast feeding delays the onset of the disease. PATIENTS AND METHODS: This retrospective study attempts to evaluate the respective contributions of these two parameters in the determination of the age at onset of the symptoms in celiac Tunisian children. RESULTS: One-hundred-sixty-nine children were studied. Mean duration of breast feeding in our population was 9.6 +/- 8.9 months and mean age of gluten introduction was 5.6 +/- 3.2 months. The mean age at onset of the disease was 15 +/- 8.7 months and mean latency time between gluten introduction and onset of the disease was 9.5 +/- 7.8 months. Both variables, duration of breast feeding and age at gluten introduction were strongly correlated to the age at onset of the disease (r = 0.47 and 0.40, respectively). Only breast feeding was correlated to the variable latency time (r = 0.33). Stepwise multiple regression analysis showed that the two variables independently influenced the age at onset with coefficients of regression of 0.90 +/- 0.20 and 0.26 +/- 0.07, respectively. Only breast feeding influenced the latency time with a coefficient of regression equal to 0.26 +/- 0.07. DISCUSSION: Our study confirms the independent effect of breast feeding in the determination of the age at onset of the disease. Breast feeding has two effects: an indirect effect, by delaying the introduction of gluten, and a direct effect, by increasing the latency time between gluten introduction and onset of the disease. CONCLUSION: Prolonged breast feeding, at least until the 6th month, and gluten introduction started at least at the 5th month of life, significantly delay the onset of the disease. Gluten introduction should be done progressively and under breast feeding protection. Introduction of gluten 2 months before weaning has a protective effect.

[Mucoviscidosis: comparative analysis of epidemiological data of French and North American registries]. / Mucoviscidose: analyse comparative des données épidémiologiques des observatoires français et nord-américains.

A national registry for cystic fibrosis was established in France in 1993. A questionnaire is sent once a year to different health care units. The first questionnaire was analyzed in 1992: 1,893 patients (53% males) were identified. 28% were over 15 years of age, 13% more than 20, and 1% over 35. Usually, diagnosis had been suggested by respiratory signs, followed by digestive tract signs and growth impairment and meconial ileus. 13% were diagnosed in screening programmes. Diagnosis was made before 1 year in 66% of the subjects (mean = 7 months). All the data collected and the functional and bacteriologic data were compared with those observed in the United States and Canada. It should also be noted that 38 patients were grafted during this study year and that it is too early to analyze the general outcome for all subjects. The creation of this registry is an important step towards a better understanding of the epidemiology of cystic fibrosis in the French population.