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Biomedical subjects

H Rivera

Publications and source records attributed to H Rivera.

At least 127 records · Page 7Linked to original sources
PubMed1986

Reciprocal translocations between acrocentrics: segregational analysis in twenty-nine families with unbalanced progeny.

This study comprises 29 families with 42 unbalanced offspring in which reciprocal interacrocentric translocations (RIATs) were identified by banding. The observed unbalances were due to adjacent-1 (42.9%), adjacent-2 (28.6%) and 3:1 (28.6%) segregations. The concordance between the observed and expected segregations was 85.7% according to the Jalbert et al. (1980) criteria. 17.2% of the RIATs led to unbalances by 2 different segregations. 78.6% of the cases were maternal in origin. The overall incidence of spontaneous abortion was 37%. Corrected recurrence risks of unbalanced liveborn offspring for female and male carriers were seemingly similar: 17.8% and 12.5% respectively. These data indicate that RIATS exhibit (as distinctive features) an approximate 4:3:3 ratio for adjacent-1, adjacent-2 and 3:1 segregations, and a proneness to produce unbalances by different segregations.

Abortion, Spontaneous↗
PubMed1986

Centric fission consequences in man.

The authors summarise the consequences of centric fission in man as follows: classical (monocentric) isochromosomes; usually either for p or q, exceptionally for both arms; stable telocentrics for either one or both arms; isochromosome for one arm, stable telocentric for the other; isochromosome for one arm concurring with translocation of the telocentric for the other; telocentric/isochromosome mosaicism for the same arm; stable telocentric for a part of one arm, the remaining of the chromosome forming a smaller element (obviously this rearrangement requires an additional break outside the centromere), and whole-arm translocations. These events are discussed in the light of current notions about centromere structure and function.

Centromere↗
PubMed1986

Trisomy 6qter resulting from a familial (6;10) (q23;q26) translocation.

An infant deceased at 2 months of age was found to have a 46,XY,-10, +der(10),t (6;10) (q23;q26) mat karyotype. Since the clinical findings were similar to those of the trisomy 6qter syndrome, the present observation agrees with the assignment of the 6q23----qter segment as the pathogenetic determiner of this entity.

Chromosome Banding↗
PubMed1985

The ac field patterns about living cells.

The presence of the small ac electric fields produced by living cells is shown by the gentle dielectrophoretic force on tiny dielectric particles. The beauty of the field patterns is made evident as the cell and particles settle in a hanging drop. Patterns characteristic of repulsion and of attraction, as well as of a dipolar and quadripolar nature, are observable.

Animals↗
PubMed1985

De novo t(4;5)(q3100;q2200) with del(5)(q1500q2200). Tentative delineation of a 5q monosomy syndrome and assignment of the critical segment.

An 8-month-old boy with multiple malformations and psychomotor retardation was found to have a de novo t(4;5)(q1300;q2200) with del(5)(q1500q2200). The phenotypical comparison with 10 similar monosomic cases from the literature led us to tentatively delineate a 5q monosomy syndrome and to postulate the band 5q15 as the correspondent critical segment.

Abnormalities, Multiple↗
PubMed1985

Monosomy 16q: a distinct syndrome. Apropos of a de novo del(16) (q2100q2300).

A 2-month-old boy with delayed growth and development, brachycephaly, large anterior fontanelle, low-set folded ears, micrognathia, aortic coarctation, floppy abdominal muscles, and pes varus, was found to have a 46,XY,del(16)(q2100q2300) de novo karyotype. This observation corroborates both the distinctness of the 16q monosomy syndrome and the pathogenetic role of the band 16q21.

Abnormalities, Multiple↗
PubMed1985

Monosomy 13q32.3----qter: report of two cases.

Two unrelated patients with monosomy 13q32.3----qter are reported. Comparison with six similar cases previously published indicates that the craniofacial dysmorphism of the 13qter monosomy syndrome is related to band 13q34, the thumb hypoplasia to band 13q32, and an apparently different phenotype to band 13q33. Coagulation deficiency appears to be non-specific in monosomy 13qter.

Child, Preschool↗
PubMed1985

Constitutional mosaic t(2;7)(q33;p22) and other rearrangements in a girl with Wilms' tumor.

A 2-year-old girl with sporadic unilateral Wilms' tumor (WT) not associated with aniridia was found to have, besides other chromosome abnormalities, a t(2;7)(q33;p22) in 6% of her lymphocytes. A comparison with 7 previous WT cases without aniridia in whom diverse chromosomal aberrations were present, reveals a wide heterogeneity and lead us to tentatively classify such changes as causal, secondary, and casual.

Child, Preschool↗
PubMed1985

The prezygotic origin of structural mosaicisms.

A theoretical model to explain the occurrence of some structural mosaicisms is proposed. It is based on a prezygotic (meiotic) half chromatid mutation leading, after the first post-zygotic DNA replication, to a structural mosaic.

Animals↗
PubMed1985

46,XX,-12,+der(12),rcp(3;12)(p25.1;p13.31)pat karyotype in a girl. Probable subregional assignment of glyceraldehyde-3-phosphate dehydrogenase locus to 12p13.1----p13.31 by exclusion mapping.

A female infant with partial trisomy 3p and a terminal deletion 12p, due to a paternal (3;12)(p25.1;p13.31) translocation is described. Normal glyceraldehyde-3-phosphate (GAPD) activity in the proposita tentatively excludes GAPD locus from the deleted segment. Therefore, the region for this locus is reduced to 12p13.1----p13.31.

Abnormalities, Multiple↗
PubMed1985

Monosomy 20p due to a de novo del(20)(p12.2). Clinical and radiological delineation of the syndrome.

A 16 year-old boy with monosomy 20p was studied. The clinical and radiological data compared with those from the three previously reported cases, permit the delineation of a distinct syndrome of low birthweight, flat face, low nasal bridge, long philtrum, short neck, small overfolded ears, chest deformity, kyphoscoliosis, congenital heart defect, hypoplastic or absent ribs and rachischisis (butterfly-shaped vertebral bodies). The critical chromosome segment causing this syndrome is tentatively defined as 20p13.

Abnormalities, Multiple↗