Prenatal diagnosis of Opitz (BBB) syndrome in the second trimester by ultrasound detection of hypospadias and hypertelorism

Prenatal diagnosis in a kindred with the Opitz (BBB) syndrome is presented. The inheritance is consistent with either autosomal dominant inheritance with sex limited expression or X-linked inheritance. The abnormalities in the kindred consist of hypertelorism, hypospadias, ambiguous genitalia, urocolic fistula, imperforate anus, mental retardation, diaphragmatic hernia, and malrotation with volvulus. A male fetus at 19 weeks was found by ultrasound to have hypertelorism and hypospadias with a small phallus consistent with the syndrome. The diagnosis was confirmed by pathologic examination after pregnancy termination. This is the first report of prenatal diagnosis of Opitz syndrome by ultrasonographic demonstration of hypertelorism and hypospadias in the second trimester.     

Prenatal diagnosis and post-mortem study of a fetus with mosaic trisomy 14 due to a dic(14)(p11)

Amniocentesis at 17 weeks' gestation revealed a mosaic karyotype—46,XX/46,XX, — 14,+dic(14)(p11). No abnormalities were detected on ultrasound. Growth and placentation were normal. The fetus was examined after termination of pregnancy and micrognathia and pulmonary hyperlobation were the only abnormalities detected. Several tissues were set up for cytogenetics, including fetal skin, kidney, ovary, and placenta. The diagnosis was confirmed by these studies. The level of mosaicism varied between tissues, with the trisomy 14 cell line highest in amniotic fluid.     

Hepatic calcifications in a fetus with trisomy 9 that underwent cordocentesis

Foci of calcification were observed at autopsy in the liver of a fetus with complete trisomy 9 on which two cordocenteses had been performed. It is suggested that liver calcifications are a possible complication of the procedure. As several other cases of calcifications in the liver and other organs of fetuses with autosomal trisomies have been described without a history of cordocentesis, further studies should be carried out to determine whether fetuses with chromosomal anomalies are more prone to thrombus formation and embolization.     

Chorionic villus sampling—short-term versus long-term culture in a subtle 2; 18 translocation

Prenatal diagnosis on chorionic villous tissue was performed for a woman with the karyotype 46,XX,t(2;18)(q32;q12)—a subtle ‘difficult’ translocation. The case illustrates the necessity of good quality cytogenetics for accurate prenatal diagnosis. For chorionic villi this can be obtained only with long-term culture.     

Prenatal diagnosis of neurofibromatosis type 1: From flanking rflps to intragenic microsatellite markers

Even though the neurofibromatosis type 1 (NF1) gene was cloned more than 3 years ago, the process of identifying mutations has not been fruitful, and genetic counselling is mainly based on the use of linked markers. Since 1990, we have analysed 130 NF1 families and have performed six prenatal diagnoses. In each case, genetic counselling has relied on linked markers and informativity was achieved in all of them. The use of intragenic microsatellite polymorphisms (IVS27AAAT2.1, IVS27AC28.4, IVS27AC33.1, and IVS38GT53.0) has increased the informativeness in our series of NF1 families to an average of 90 per cent, providing accurate diagnosis and confirmation of the disease status.     

Prenatal diagnosis of cleft lip and palate by ultrasound

Bilateral cleft lip and cleft palate can be diagnosed by ultrasonography prior to 20 weeks of pregnancy. The anomaly produces an abnormal facial profile and, on cross-section, the clefts in the maxilla are demonstrable. The method is illustrated by sonograms from a fetus in which the defect was diagnosed before trisomy 13 became known by karyotyping.     

The biodiversity crisis and the future of evolution

A large proportion of existing species — possibly half, conceivably even more — may be lost within the foreseeable future. But this may not prove to be the most consequential outcome of the current biodiversity crisis. More significant could be the disruption and degradation of several basic processes of evolution. It appears likely that for mass extinction episodes (MEEs) in the geological past, the recovery period usually lasted at least five million years. Because of certain unique features of the present MEE — notably the near elimination of biomes such as tropical forests, wetlands and coral reefs, which have served as powerhouses of evolution in the past — the bounce-back phase could extend several times longer than five million years. Among distinctive features of future evolution could be; in the short term, homogenization of biotas, a proliferation of opportunistic species, an outburst of speciation among particular taxa, and a pest-and-weed ecology; and, in the long term, a decline of biodisparity, the elimination of megavertebrates, an end to speciation among large vertebrates, and multiple constraints on origination, innovation and adaptive radiation. These disruptive phenomena would rank among the most prominent departures in the entire course of evolution. Full knowledge and understanding of what may characterize future evolution remains largely a black hole of research. As a consequence, conservation policies fail to reflect a further problem of the biodiversity prospect, perhaps exceeding the better recognized problem of the mass extinction of species.Professor Norman Myers is an Editorial Board member and regular contributor toThe Environmentalist. He is an Honorary Visiting Fellow at Green College, Oxford. This paper is a greatly expanded version of a preliminary probing in a popular magazine a decade ago (Myers, 1985). It has been prompted by a major international conference organized by the US National Academy of Sciences, scheduled for late 1996.     

Our forestry prospect: the past recycled or a surprise-rich future?

NORMAN MYERS: An honorary visiting fellow at Green College. He is an independent scientist and consultant working in environment and development.Like most other environmental and economic sectors, forestry worldwide looks set to encounter a growing number of surprises in the sense of major divergencies from established trends. These surprises will be largely environmental or economic or both at once. Unless we do a better job of identifying them ahead of time, these surprises will often be of a scale to overwhelm our anticipatory and preventive capacities. Indeed and as this paper demonstrates, the most likely as well as the most taxing forestry problems of the future will often be the ones we have scarcely thought of. Fortunately, the same applies to forestry opportunities. In these circumstances, there is a premium on not only supplying answers to recognized questions but on raising entirely new questions.     

Ecosystem management to achieve ecological sustainability: The case of South Florida

The ecosystems of South Florida are unique in the world. The defining features of the natural Everglades (large spatial scale, temporal patterns of water storage and sheetflow, and low nutrient levels) historically allowed a mosaic of habitats with characteristic animals. Massive hydrological alterations have halved the Everglades, and ecological sustainability requires fundamental changes in management.The US Man and the Biosphere Human-Dominated Systems Directorate is conducting a case study of South Florida using ecosystem management as a framework for exploring options for mutually dependent sustainability of society and the environment. A new methodology was developed to specify sustainability goals, characterize human factors affecting the ecosystem, and conduct scenario/consequence analyses to examine ecological and societal implications. South Florida has sufficient water for urban, agricultural, and ecological needs, but most water drains to the sea through the system of canals; thus, the issue is not competition for resources but storage and management of water. The goal is to reestablish the natural system for water quantity, timing, and distribution over a sufficient area to restore the essence of the Everglades.The societal sustainability in the Everglades Agricultural Area (EAA) is at risk because of soil degradation, vulnerability of sugar price supports, policies affecting Cuban sugar imports, and political/economic forces aligned against sugar production. One scenario suggested using the EAA for water storage while under private sugar production, thereby linking sustainability of the ecological system with societal sustainability. Further analyses are needed, but the US MAB project suggests achieving ecological sustainability consistent with societal sustainability may be feasible.