Pericentric inversion in a family with a 21/22 translocation

Abstract

A pericentric inversion has been discovered in one branch of a family, in which a 21/22 translocation of the usual type had been transmitted through three generations. The female carrier of the translocation with inversion appears to be phenotypically normal. She has, however, an obvious tendency to develop aneuploid offspring.

C-banding patterns inSalmo trutta, a species of tetraploid origin

“…1, b and g) may well have originated by pericentric inversion of metacentrics in a secondary step after centric fusion. In human chromosomes, two types of structural changes, namely a 21/22 translocation followed by pericentric inversion have also been observed (SOUDEK et al, 1968).…”

Cytological assessment of meiotic exchange in a human male with a pericentric inversion of chromosome No. 4

“…Although recombinant offspring can arise through meiotic crossing-over in both human male and female carriers (Morishima et al, 1964;Soudek et al, 1968;Parrington et al, 1971;Faed et al. 1972;Hauksdottir et al, 1972, two cases; Surana and Conen, 1972;Crawfurd and Mason, 1973;D utrillaux et al" 1973), existing data are inadequate to determine whether recombination occurs at the same or different frequencies in the two sexes.…”

“…It seems certain that this limitation is partly responsible for the relatively low number of reported pericentric inversions in man and the almost complete lack of paracentric inversions in the literature. Several dozen suspected inversion chromosomes ascertained with nonbanding techniques include those of the A-, B-, C-, and D-group chromosomes (G ray et al, 1962;Chandra and Hungerford, 1963;G rouchy et ai.. 1963Morishima et al, 1964; Lejeune and Berger, 1965;Cohen et al, 1967;J acobs et al" 1967;Schneider et al, 1967;Soudek et al, Keutel and Schubert, 1969;O rye et al, 1969;Weitkamp et al. 1969; C randall and Parrington and Edwards, 1971; Surana and Conen, 1972;Hayata et al, 1973).…”

“…Heterozygous inversions in man rarely seem to be the primary cause of congenital abnormalities (Soudek et al, 1968;Wahrman et al, 1972), and pericentric inversions in chromosome 9 are now recognized frequently enough in routine banding analysis to be considered as another form of polymorphism (F erguson-Smith, 1973;G eraedts and Pearson, 1974). Chromosome 9 inversions do not result in a greatly increased incidence of abnormal conceptuses (Wahrman et al, 1972;Ferguson-Smith, 1973), and this has been substantiated in family studies involving inversion in other chromosomes (Wilson et al, 1970).…”

A t(21q21q) Ring Chromosome

“…Some of them are complex G/G translocations or secondary rearrangements of them, such as a G/G tandem chromosome with satellites on both arms [Richards et al. 1965;Vogel et al, 1970;BartschSANDHOFFand Sc'Made, 1973], an atypical G/G translocation derived from a pericentric inversion chromosome [Moric-Petrovic et al, 1972], and a pericentric inversion of a G/G centric fusion [Soudek et al, 1968;Orye et al, 1969].…”