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

Abstract

Mitotic chromosome studies carried out on a newborn male infant with congenital abnormalities and on his family members showed that the father and paternal grandmother were heterozygotes for an unequal pericentric inversion. The child appeared to have inherited a recombinant duplication/deletion chromosome. The results of meiotic studies carried out on a testicular biopsy from the father were used to ascertain the risk of recurrence of chromosomal abnormalities in future pregnancies. A model is presented which permits the analysis of C-banded diakinetic chromosomes as to whether crossing-over has occurred within the inversion segment or not. In the present study, it was estimated that either one or two cross-overs had occurred in 52 % of the cells within the inversion segment. This would result in approximately 26% of the spermatozoa carrying either one of two types of duplication/deficiencies of chromosome No. 4.

A second case of inv(4)pat with both recombinants in the offspring: rec dup(4q) in a girl with Wolf-Hirschhorn syndrome and rec dup(4p)

“…Both alternative recombinants of chromosome 4 have been described in the literature (Villa et al 1995). The average chiasma frequency for the normal chromosome 4 has been estimated to be 2.79 (ISCN, 1985), and chiasma distribution within the inversion bivalent is thought to be similar (Van der Linden et al, 1975). There is also an indication for nonrandom distribution of chiasmata along the bivalent, with an excess of terminal chiasmata (Hultén, 1974).…”

Paracentric inversion of chromosome 15(q15q24): description of three families

“…T h e r e f o r e , the inversion, in a large n u m b e r of cases, has no significant effect on r e p r o d u ctive fitness ( M a d a n 1988). Meiotic studies (Van D e r Linden et al 1975;Lin et al 1987;D e Perdigo et al 1989) and d a t a on p r e n a t a l diagnoses (Daniel et al 1989) show that a n e u s o m i c r e c o m b i n a n t k a r y o t y p e s from inversion carriers, in clinical abortions or in liveborn children, are u n d o u b t e d l y rare ( M a d a n 1988; W o r s h a m et al. 1989).…”

The critical monosomic segment involved in 4p- syndrome: A high-resolution banding study on five inherited cases

“…As far as we know, our case 3 is the second example of a patient with 4p-syndrome resulting from a parental pericentric inversion of chromosome 4. ~The first reported case with a recombinant chromosome 4 due to a parental inversion, on the other hand, had gross trisomy for 4q25 ~ qter in addition to m o n o s o m y for 4p14--* pter (van der Linden et al, 1975).…”