Prenatal sex diagnosis: Testosterone and fsh levels in mid-trimester amniotic fluids

We studied the validity of mid-trimester amniotic fluid testosterone and FSH in the diagnosis of fetal sex in abnormal fetuses and in twins. It was found that the testosterone/FSH ratio, but not the level of the individual hormones, was an excellent criterion for fetal sex diagnosis. In a control group of 32 female and 34 male fetuses, the testosterone/FSH ratio was diagnostic. In two cases the values were indeterminate and fetal sex could not be predicted, but there were no false diagnoses. The abnormalities of the fetuses were diagnosed by karyotype analyses or raised levels of α-fetoprotein. It was found that neither autosomal trisomies nor X-chromosome aneuploidy or neural tube defect interfered with the diagnostic value of the hormonal approach. The twin study included 14 pairs, three of whom were discordant for sex. In all twins the fetal sex diagnosis was appropriate. In co-twins of the same sex the hormone levels were very close to each other.     

Uniparental disomy in fetuses diagnosed with balanced Robertsonian translocations: risk estimate

Forty-two fetuses with non-homologous Robertsonian translocations were analyzed for uniparental disomy (UPD). One fetus with a de novo translocation t(13q;14q) had maternal isodisomy of chromosome 14. In a summary of the published data (including the present study), 315 cases were analyzed for UPD after prenatal diagnosis of balanced Robertsonian translocations, of these two fetuses had UPD, giving a risk estimate of 0.65% (CI 0.2–2.3). This risk justifies the recommendation of UPD analysis in fetuses diagnosed prenatally with Robertsonian translocations, with the emphasis on the chromosomes known to contain imprinted genes, such as 14 and 15. We also discuss the possibility of UPD in offspring of Robertsonian translocation carriers with normal karyotype. Based on the risk for UPD in fetuses with Robertsonian translocation we suggest to test these fetuses for UPD and to do so on amniocytes rather than chorionic villi when the risk for unbalanced karyotype is ∼1%, comparable to the risk for UPD. Copyright © 2002 John Wiley & Sons, Ltd.     

Biodegradation of dibromoneopentyl glycol by a bacterial consortium

Dibromoneopentyl glycol (DBNPG) is a brominated flame retardant that is used as an additive during the manufacture of plastic polymers and as a chemical intermediate for other flame retardants. It is classified as not readily biodegradable and based on experimental studies in animals is believed to be a carcinogen. We have demonstrated, to the best of our knowledge for the first time, the complete biodegradation of DBNPG under aerobic conditions. Total organic carbon (TOC) analysis indicates the complete mineralization of DBNPG. DBNPG biodegradation was accompanied by the release of bromide into the medium, probably due to a biological debromination reaction by bacterial consortia. A denaturing gradient gel electrophoresis (DGGE) analysis of PCR amplified 16S rRNA gene was used, to characterize the bacterial consortia involved in DBNPG biodegradation. At least seven bacterial species were found to be involved in this process, among them species with similarity to strains that are known for their dehalogenating ability.     

Prenatal ultrasonic diagnosis of radial-ray aplasia and renal anomalies (acro-renal syndrome)

Prenatal ultrasonic diagnosis of a rare case of radial ray aplasia and crossed renal ectopy is described in an affected sibling of a family where the father and his son suffer from this rare syndrome. The prenatal diagnosis enabled early pregnancy termination.