Segregation analysis in a man heterozygous for a pericentric inversion of chromosome 7 (p13;q36) by sperm chromosome studies.
We have analyzed 140 sperm chromosome complements from a subfertile man heterozygous for an inv(7)(p13;q36). Seventy-five percent of the chromosome complements were not recombinant: 37.9% contained the normal chromosome 7, and 37.1% contained the inverted chromosome 7. Twenty-five percent of the 140 were recombinant: 7.1% carried a recombinant chromosome 7 with a duplication p and deletion q, 17.1% carried a recombinant chromosome 7 with a duplication q and deletion p, and 0.7% carried both recombinant chromosomes. The frequency of structural chromosomal aberrations unrelated to the inversion was 11.4%, and the frequency of aneuploidy was 2.9%. Both frequencies were not significantly different from those in control donors. Two sperm complements with a second independent, contiguous inversion involving one of the original breakpoints (q36) were observed (1.4%). The risk of producing chromosomally abnormal offspring or spontaneous abortions would be 34.3%. The proportion of X-bearing and Y-bearing sperm was 46.8% and 53.2%, respectively, not significantly different from the expected 1:1 ratio.
Navarro
J
J
Departament de Biologia Cellular i Fisiologia, Facultat de Medicina, Universitat Autònoma de Barcelona.
Benet
J
J
Martorell
M R
MR
Templado
C
C
Egozcue
J
J
D000328:Adult; D007446:Chromosome Inversion; D002897:Chromosomes, Human, Pair 7; D005260:Female; D006579:Heterozygote; D006801:Humans; D007248:Infertility, Male / Q000235:genetics; D007621:Karyotyping; D008297:Male; D010375:Pedigree; D013094:Spermatozoa / Q000648:ultrastructure*