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Biomedical subjects

R Niss

Publications and source records attributed to R Niss.

3 recordsLinked to original sources

Partial trisomy 13 presumably due to recombination in an inversion heterozygote and by unequal crossing-over.

Two unrelated infants with partial trisomy 13 for the distal of the long arm are described. In one, a familial pericentric inversion is present in three generations and crossing-over in the inversion loop is considered as cause of partial trisomy 13. The other showed a tandem duplication of the distal half of the long arm of chromosome 13 beyond 13q14. This is interpreted to have arisen by unequal crossing-over in mispaired synapsis. It is suggested that recombination rather than breaks is a distinctive although rare cause of human chromosomal imbalance.

Chromosome Inversion↗

Trisomy 8 restricted to cultured fibroblasts.

In the course of re-examing cultured fibroblasts stored in liquid nitrogen from a patient with developmental retardation, solitary left kidney, and Wilms tumour, a cell line trisomic for chromosome 8 was found. Trisomy 8 was restricted to fibroblasts in the first 22 subcultures and was absent in later passages as well as in lymphocytes. A familial pericentric inversion of chromosome 2 was observed in three generations including the propositus but was though to be unrelated to the clinical problem. Multiple spontaneous chromosomal rearrangements were seen in several late subcultures.

Cells, Cultured↗

Derivative chromosomal structures from a ring chromsome 4.

This report describes the results from cultured lymphocytes studied at metaphase, anaphase, and interphase from an individual with a ring chromosome 4. A ring was present in 90.1% of metaphases. Special attention was directed towards the occurrence of derivative chromosomal structures, such as partially duplicated and triplicated rings, tricentric rings, chains of 3 interlocked rings, rod-shaped chromosomes, "pulverized" rings, and others. The clinical features of the individual (small stature and impaired mental development, hypoplastic thumbs, ptosis palpebrae hypoplastic external male genitalia, abnormal dermatoglphic pattern) did not conform to a specific phenotype.

Blood Group Antigens↗