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Biomedical subjects

J Lejeune

Publications and source records attributed to J Lejeune.

At least 91 records · Page 5Linked to original sources
PubMed1980

[Increase of LDH A and partial trisomy 11p (author's transl)].

An increase of LDH A activity is observed in an adolescent patient trisomic for 11p with the exception of band 11p13. The clinical syndrome is delineated: broad faces, abundant eyebrows in their internal portion, enophtalmia, hypoplasic nasal bridge, hypertelorism, epicanthus, cleft palate or lip, macroglossia, hypotrophic muscles, soft and abundant skin, mental retardation.

Abnormalities, Multiple↗
PubMed1979

[Oral contraceptives and trisomy 21. A retrospective study of 730 cases (author's transl)].

A retrospective study of 730 cases of trisomy 21 and of 1 035 cases of abnormal children without a detectable chromosomal aberration, allows the study of the frequency of use of oral contraceptives by their mothers. The statistical analysis shows no notable differences for mothers 30 years old and younger. Among the mothers 30 to 38 years old, these is an excess of pill-taking by mothers of trisomy 21 children. For this second category of mothers (30 to 38 years) this excess is significant (a) when the delay between the cessation of pill-taking and the conception of the child is six months of less; (b) when the duration of pill-taking has been longer than one year; and (c), when those two factors are present simultaneously. Moreover, the frequency of males is significantly reduced in trisomy 21 children when their mothers have taken the pill. As a whole, for the subsample of mothers 30 and older, a correlation is observed between the three factors analysed, pill-taking, sex ratio, and trisomy 21. In view of the fact that decrease of the sex ratio and the increase of the frequency of trisomy 21 both are correlated with maternal aging in the general population, it seems remarkable that a correlation between these two variables and the use of oral contraceptives is observed only when the women had already passed the first of their reproduction period.

Adolescent↗
PubMed1979

[Biochemical investigations and trisomy 21 (author's transl)].

A general consideration of the pathogenesis of the various metabolic diseases which produce mental deficiency suggests that perturbation of the one carbon (folate) cycle may be important. Secondly, a review of diseases having some symptoms in common with trisomy 21 suggests the evidence of : a collagen disturbance (hypothyroidism and iminodipeptidurial) ; an oxygen disturbance (hypothyroidism and hemoglobinopathies) ; a cholinergic distrubance (Alzheimer's disease) ; a one-carbon-cycle disturbance (Lesch-Nyhan's disease). Thirdly, the peculiar pathology of trisomy 21 allows to find also a cholinergic disturbance and a disturbance close to the 10 formyl-tetrahydrololate entry of the folate cycle. Finally, an analysis of the possible effect of the excess of superoxide dismutase A and of the increase of glutathion peroxidase leads to the suspicion that a difficulty exists of dioxygenations and of non aromatic hydroxilations with a relative retardation of some FAD requiring reactions. A simplified scheme shows that these metabolic deviations could provoke a disturbance of the collagen and of synthesis of chemical mediators, in accordance with the indications furnished by the compared pathogenesis of the various affections studied. These heuristic reflexions open the way to further investigations.

Down Syndrome↗
PubMed1979

[46,XX/46,XX,del (10) (p13)/47,XX,+r/47,XX,del (10) (p13), + r mosaicism and partial trisomy 10p phenotype (author's transl)].

The mosaicism 46,XX/46,XX,del(10)(p13)/47,XX, +r/47,XX,del(10)(p13), +r was found in the lymphocytes and the fibroblasts of a patient with the following : profound mental retardation; craniofacial dysmorphism with frontal bossing, fine eyebrows, a large hypoplastic nasal bridge, prognathism of the upper jaw, thick lips; a long and thin neck; congenital heart disease; skeletal malformations, with club feet; and hypotonia and lax ligaments. These malformations, compatible with the trisomy 10p syndrome, suggest that the supernumerary ring chromosome was composed of 10p material. An increase of HK1 and GOT1 activities was found. This is in favour of a partial trisomy of chromosome 10. The relative frequencies of the clones constituting the mosaic vary from tissue to tissue and with time.

Abnormalities, Multiple↗
PubMed1979

[A jumping translocation (5p;15q), (8q;15q), and (12q;15q) (author's transl)].

Three balanced karyotypes (5p;15q), (8q;15q), and (12q;15q) were found simultaneously in a child with the Willi-Prader syndrome. The hypothesis is presented of a "jumping# translocation by affinity of telomeric and interstitial palindromes. The relationship between the Willi-Prader syndrome and a juxtacentric anomaly of the long arm of chromosome 15 is discussed.

Child, Preschool↗
PubMed1979

[De novo monosomy 4q32.1 leads to 4qter in a newborn with multiple malformations (author's transl)].

In a newborn with multiple malformations, deletion 4q32.1 leads to 4qter was observed after BrdU incorporation and staining with acridine orange. The patient's phenotype and that of five children monosomic for 4qter reported in the literature define a syndrome with a high rate of mortality due to major respiratory difficulties, laryngeal hypotonia and oedema, and complex congenital heart malformations.

Abnormalities, Multiple↗
PubMed1978

Systematic analysis of 95 reciprocal translocations of autosomes.

The statistical analysis of 95 cases of reciprocal translocations involving autosomes detected among about 10,000 patients studied with the R-banding technique gives the following information: 1. An excess of break points exists for chromosome arms 4p,9p, 10q, 21q, and 22q and a deficiency for 1p, 2p, and 6q. Furthermore, there are relatively more break points in the small arms than in the large arms, when the translocation is ascertained through an unbalanced translocation carrier. Except for chromosome 22, an ascertainment bias explain this non random distribution. 2. An excess of telomeric break points exists in all cases of translocations ascertained through unbalanced carriers, and an excess of centromeric break point exists in the case of 3:1 and 1:3 segregations only. These excesses are also explained by an ascertainment bias. 3. The break points are located usually at the junction of the bands (interfaces). 4. The size of the chromosomal imbalance varies in the ascertainment classes. It is very large in cases ascertained through balanced carriers (at least one break point is far from the telomere), large in cases ascertained through abortion, and relatively moderate in cases ascertained through unbalanced translocation carriers (at least one break point is juxta telomeric). 5. An excess of balanced reciprocal translocations exists in our sample of mentally retarded and malformed children (position effect?). 6. An excess of balanced reciprocal translocations (not involving chromosome 21) exists among the trisomics 21 and their parents (interchromosomal effect?). 7. A large excess of maternal transmission exists in cases of 3:1 segregation of reciprocal translocation.

Abnormalities, Multiple↗
PubMed1978

Human somatic chromosome chains and rings. A preliminary note on end-to-end fusion.

Chain and ring chromosome configurations were detected in a small percentage of the lymphocytes of a patient suffering from Thiberge-Weissenbach syndrome. Precise recognition of the chromosomes involved in the rearrangements did not indicate a systematic order of end-to-end fusions. A relationship between these configurations and the chromosome arrangement in the interphase nucleus is possible.

Calcinosis↗
PubMed1978

[Chromosomal anomalies and intelligence deficiency (author's transl)].

The relations between chromosomal diseases and mental retardation can be envisaged in three different ways: 1) Pharmacological approach shows a peculiar sensitivity of the cholinergic system in trisomic 21 children. A trouble in the manufacture of cholinergic mediator is plausible. 2) General biochemistry shows a slight shift of the glycolytic pathway in trisomics 21 as well as some localised abnormalities of amino-acids. 3) Gene mapping allows the localisation of the main responsable genes on band q22. 1 and among them the gene coding for superoxide dismutase 1. Also glutathion peroxidase is elevated. These disparate facts are discussed in the light of a model of the machinery regulating the production of chemical mediators. Comparison with other diseases lead to the hypothesis that rather simple and localised mechanisms could be specially important.

Chromosome Aberrations↗
PubMed1977

[Congruence of monotonous DNA/protein polymers].

The comparative study of the monotonous polynucleotides and polypeptides reveals an univocal congruence between: poly-C and poly-PRO;poly-G and poly-GLY;poly-T and poly-PHE;poly-A and poly-LYS. The hypothesis is presented of a code of congruence ruling the specific recognition of the wide groove of the DNA by proteins.

Chemical Phenomena↗
PubMed1977

12pter to 12p12.2: possible assignment of human triose phosphate isomerase.

Red cell triose-phosphate isomerase (TPI) was determined, together with other enzymes, in three patients with chromosome 12 abnormalities. In patient No. 1 (trisomy of the segment 12 pter leads to 12q 12) and in patient No. 2 (trisomy of the segment 12pter leads to 12p 12.1), the TPI activity was significantly increased. In patient No. 3 (deletion of the segment 12 p 11 leads to 12 p 12.2), the TPI activity was in the normal range. These results suggest that the human TPI locus is located on the chromosome 12 short arm, between 12p ter and 12 p 12.2.

Carbohydrate Epimerases↗