Early amniocentesis from 9 to 14 weeks' gestation provides a safe and accurate method of prenatal diagnosis of cytogenetic and biochemical disorders. There was a 100 per cent success rate in culturing the amniotic cells from 222 samples obtained between 9 and 14 weeks' gestation. Follow-up of the patients to delivery revealed an abortion rate of 1.4 per cent. Among the 207 live- and stillborn infants, only one had a congenital abnormality (bilateral talipes equino-varus) and no infant had respiratory distress syndrome or pneumonia. Eleven pregnancies were terminated following the detection of a chromosomal, biochemical, or congenital abnormality (5.0 per cent). However, before the procedure of early amniocentesis becomes routine clinical practice, it requires appraisal by a randomized clinical trial.

Two male infants with almost complete trisomy 16q due to a maternal translocation, are reported. The phenotypic similarities of these patients who had trisomy 16q11 leads 16qter and of the eight previously published reports of partial trisomy 16q, were compared.

A rapid PCR based assay was used to ascertain the presence of maternal cell contamination (MCC) (J Med Genet 1995;32:61-64)

No abstract

A 37-year-old woman was referred for genetic counseling after termination of her probable seventh pregnancy. Ultrasound examination at 13 weeks of gestation had shown a fetus with bilateral cystic hygromas. A transabdominal amniocentesis confirmed 45,X karyotype in the fetus. The patient had marked short stature and a 45,X chromosome constitution in blood lymphocytes. Subsequently she had a hysterectomy and oophorectomy. Tissue of representative sites of the pathological specimen showed a 45,X chromosome constitution. However, molecular analysis of 8 sites from the uterus and ovaries, and of skin fibroblasts with X-chromosome microsatellites showed the presence of only one allele, except for the microsatellite DXS996 which demonstrated 2 alleles (155 bp and 161 bp) in ovarian tissue. The lymphocytes from the mother and her only son demonstrated the same single allele (161 bp). We conclude that molecular analysis of lymphocytes and of tissue is necessary for detecting low-level mosaicism in apparently homogeneous 45,X women.