Maternal sex chromosome mosaicism diagnosed by amniocentesis and percutaneous umbilical cord sampling

We present a remarkable chain of events in which percutaneous umbilical cord sampling was performed in an attempt to clarify a situation of possible fetal sex chromosome mosaicism in an amniotic fluid culture and led to the discovery that the mother herself had a 45,X/46,XX/ 47.XXX chromosome constitution. This may have simply represented the chance concurrence of pseudo-mosaicism in the amniotic fluid culture of a woman with an abnormal sex chromosome constitution, but it is also possible that the 45,X colony was maternal in origin. Although clearly a most unusual circumstance, the possibility should be kept in mind when termination of a pregnancy is being considered because of apparent mosaicism in a prenatal diagnostic study.     

Carbon Dioxide Emission Reduction Scenarios in Mexico for Year 2005: Industrial Cogeneration and Efficient Lighting

An analysis of the impacts on Mexican energy demand and associated carbon dioxide (CO₂) emissions in the year 2005 due to efficient lighting in the commercial and residential sectors and cogeneration in the industrial sector is presented. Estimation of CO₂ abatement costs and an incremental cost curve for CO₂ mitigation options are considered. These technologies are cost effective opportunities, and together are projected to reduce CO₂ emissions in 2005 by nearly 13 percent. Implementation of efficient lighting is already part of the demand side management (DSM) programs of the Mexican state-owned utility. However, there are important barriers that may hinder the implementation of large scale cogeneration plants.     

Reproductive behaviour and prenatal diagnosis following genetic termination of pregnancy in women of advanced maternal age

One hundred and fifty-one women of advanced maternal age who underwent genetic termination of pregnancy (TOP) were studied for their reproductive behaviour and the type of procedure for prenatal diagnosis in a subsequent pregnancy. A total of 59 women (39 per cent) had a further pregnancy. In all continuing pregnancies prenatal diagnosis was performed, of which 75 per cent consisted of chorionic villus sampling (CVS). Reproductive behaviour following a genetic termination was negatively correlated with maternal age and parity. Both reproductive behaviour and the choice to undergo a diagnostic procedure in the next pregnancy were independent of the type of diagnostic procedure in the previous affected pregnancy.     

Prenatal diagnosis of spinal muscular atrophy in Russia

Ninety-two families with spinal muscular atrophy (SMA) applied for genetic counselling and further prenatal diagnosis. To minimize expenses, only one tightly linked informative marker was determined in the course of preliminary examination, and non-radioactive allele detection was preferably used. Four prenatal diagnoses of SMA type I, four of SMA type II, and one of SMA type III were made. This trial programme shows the considerable requirements, importance, and potential effectiveness of prenatal prediction of SMA in Russia.     

False-negative amniotic fluid acetylcholinesterase in a case of meningo-encephalocele

We describe a patient with a significantly elevated serum alphafetoprotein (AFP) concentration at 17 weeks of gestation, who showed only a marginally increased amniotic fluid AFP and lacked the second rapidly migrating band of acetylcholinesterase electrophoresis. Ultrasound examination revealed an encephalocele and ventriculomegaly. Autopsy showed that the encephalocele was not covered by skin.