Michel Guilloud-Bataille

Tracking the development of adiposity from one month of age to adulthood

The development of adiposity was followed in 164 subjects from the age of one month to adulthood. The 25th and 75th centiles of the weight/height2 (W/H2) index were chosen as cut-off points to define the lean, medium and fat subjects at both one and 21 years of age. Only 42% of the children remained in their original category, that is 41% of the lean infants at one year stayed lean, 42% of the medium infants stayed medium and 41% of the fat infants stayed fat. Accordingly, most fat infants did not stay fat, but twice as many fat as non-fat infants became fat adults (41 and 20% respectively). The relative risk of being fat adults was 1 for the lean, 1 for the medium and 2 for the fat infants at one year. Several paths of development emerged: they were related to age at the second rise in adiposity, termed adiposity rebound, which usually occurs at about six years, as observed on skinfold thickness and W/H2 charts. The earlier the rebound, the higher the adiposity at adult age, whether this was measured by W/H2 index or subscapular skinfold. The cohorts of children who left the channel they had been following included fat infants with a late rebound who subsequently returned to normal, and lean infants with an early rebound who grew fatter. Other cohorts remained in their original groups, for example, fat infants with an early rebound who stayed fat and lean infants with a late one who stayed lean. Age at rebound provided two indications: the existence of a regulartory process among the transiently fat or lean infants who returned to average after a late or early rebound respectively, and pathological development among the children who became fat or lean after an early or late rebound. Age at rebound is an indicator of the subsequent development of fatness.

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.

Confirmation of linkage of benign familial neonatal convulsions to D20S19 and D20S20.

SummaryBenign familial neonatal convulsions (BFNC) is an idiopathic form of epilepsy beginning within the first six months of life. Its genetic origin and autosomal dominant mode of inheritance have been suspected since its first description. Recently, the BFNC gene has been localised within chromosome 20q in one large pedigree. For the first time, we confirm here (with D20S19 and D20S20) the close linkage of BFNC to chromosome 20q in six French predigrees. In addition, the existence in these families of several cases of febrile convulsions (FC), another epileptic syndrome with an autosomal dominant genetic component, led us to study the possibility of a genetic background identical to BFNC. Our results suggest the existence of different susceptibility genes for BFNC and FC.

Linkage studies in X-linked Alport's syndrome.

SummaryFour kindreds segregating for Alports syndrome (ASLN) compatible with a X-linked inheritance were studied for linkage with polymorphic markers of the human X chromosome. No recombinant was observed between the ASLN locus and the DXS101 and DXS94 loci, the maximum lod scores were z=3.93 and 3.50 respectively. Linkage data between the ASLN locus and the other genetic markers used in the present study are in keeping with the assignment of the mutation to the proximal Xq arm.

Genome screen in the French EGEA study: detection of linked regions shared or not shared by allergic rhinitis and asthma

In the sample of 295 French EGEA families with at least one asthmatic subject, a genome screen was conducted to identify potential linkage regions specific either to allergic rhinitis (AR) or to asthma as well as those shared by the two diseases. Two binary rhinitis phenotypes based on (1) diagnosis (ARbin1) and (2) symptoms (ARbin2) and a categorical ordered trait (ARcat) were considered. Asthma phenotype was based on answers to a standardized questionnaire plus the presence of bronchial hyper-responsiveness. Linkage analyses were conducted using the maximum likelihood binomial (MLB) method. These analyses provided potential evidence for linkage to three regions in the whole sample: 1p31 for the phenotype defined by ARbin2 plus asthma (P=0.00016), 2q32 for ARbin2 (P=0.00016) and 3p24–p14 for ARcat (P=0.001). Two other regions were detected in the subset of 185 families with at most one asthmatic sib: 9p22 and 9q22–q34 for ARbin1 (P=0.001 and 0.0007, respectively). No region showed evidence for linkage to asthma without being also linked to AR. While 1p31 may contain a genetic determinant common to asthma and AR, 2q32, 3p24–p14, 9p22 and 9q22–q34 are more likely to harbor genetic factors specific to AR.

Spondyloepiphyseal dysplasia tarda: linkage with genetic markers from the distal short arm of the X chromosome.

SummaryA linkage study of six families with spondyloepiphyseal dysplasia tarda (SEDL) has been performed. A linkage to site DXS41 (

Evidence for linkage of a new region (11p14) to eczema and allergic diseases

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Genetic and epidemiological risk factors for a malignant melanoma-predisposing phenotype: The great number of nevi

=0.08; ž=3.07) and DXS92 (