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We present a case of a 46,XY der(13;14) Robertsonian translocation carrier whose spermatozoa were karyotyped after injection into mouse oocytes. Fresh semen samples as well as recovered samples were used. There was no significant difference in the survival rate of mouse oocytes (fresh: 78.1% versus frozen: 81.7%), activation rate (fresh: 84.0% versus frozen: 90.6%), fertilization rate (fresh: 72.0% versus thawing of frozen: 76.5%) between fresh or frozen spermatozoa. Metaphase chromosome spreads from 45 spermatozoa were analysed. The frequency of spermatozoa that were chromosomally unbalanced with respect to the translocation was 8.9%, and the frequency of abnormalities unrelated to translocation was 4.4%. An excess of spermatozoa with balanced chromosomes was observed: compared with normal, 23 (51.1%) versus 16 (35.6%) respectively; but this segregation difference was not statistically significant (χ2 = 0.9, P > 0.3). After genetic counselling with the carrier and his partner, intracytoplasmic sperm injection treatment was performed. Healthy female and male infants were delivered at 36 weeks gestation via a Caesarean section. Both babies were carriers for the balanced Robertsonian translocations detected for prenatal diagnosis at 16 weeks gestation. The present study demonstrates that patients can be given further information about the proportion of the spermatozoa which carry a chromosomal abnormality.

SummaryThe results of chromosome studies on cultured umbilical cord blood lymphocytes from a consecutive series of 14,835 liveborn infants (7,608 males and 7,227 females) are described. Ninety-three infants (6.27 per 1,000) had a major chromosome abnormality. Of these, thirty-one infants (2.09 per 1,000) had sex chromosome abnormalities. Seven male infants had a 47,XXY karyotype, five had a 47,XYY karyotype, and three were mosaics. One male had a ring Y chromosome in all cells examined. A pericentric inversion of the Y chromosome was found in one case. Seven female infants had a 47,XXX karyotype, one had a 45,X karyotype and six were mosaics. Sixty-two infants (4.18 per 1,000) had autosomal abnormalities. There were twenty-one infants with trisomy 21 including one mosaic, six infants with trisomy 18, and two infants with trisomy 13 of a Robertsonian translocation type. Three infants had an unbalanced derivative chromosome resulting from a parental reciprocal translocation. Two infants with a partial monosomy of chromosome 13 were detected. There were four infants carrying an additional small marker chromosome. Twenty-four infants (1.62 per 1,000) had a balanced structural rearrangement of the autosomes; eleven with a Robertsonian translocation, eleven with a reciprocal translocation, and two with a pericentric inversion. The incidence of each type of major chromosome abnormality in this study was quite similar to that obtained from previous newborn surveys.

SummaryCytogenetic investigations have been carried out with particular concern to the frequency of chromosome abnormalities in newborn infants, and this is a preliminary report of data derived from 2,626 consecutive liveborns (1,393 males and 1,233 females) which were collected in one hospital. Of these, 18 infants (0.69%) were found to have a major chromosome abnormality. Eight infants (0.30%) showed sex-chromosome abnormalities: two with 47,XYY, one with 47,XXX, one with 45,X/47,XXX mosaicism, one with 46,XY/47,XYY mosaicism, one with 45,X/46,XX mosaicism, and a pair of twins with 45,X/46, XY/47,XYY mosaicism. Ten infants (0.38%) were carriers of autosomal abnormalities: three with 21-trisomy, one with 13-trisomy by translocation, three with a balanced 13/14 translocation, two with a balanced 14/22 translocation and one with an extra small marker chromosome. Of chromosomally abnormal infants, 14 were phyiscally normal.