C to T and/or G to A transitions are responsible for loss of a MspI restriction site at the 5′-end of the human apolipoprotein AI gene

We detected the loss of a MspI restriction site by a C to T transition at +83 bp and a G to A transition at +84 bp of the 5-end non-coding region of the human apolipoprotein AI gene. This base change occurred at the hot spot (CCGG) for methylation, which may be important in the regulation of gene expression. The population frequency for the loss of the MspI site is 6.1%.     

A 45‐bp Insertion/Deletion Polymorphism of Uncoupling Protein 2 in Relation to Obesity in Tongans

We compared the current prevalence of increased BMI and type 2 diabetes in a representative group of Tongan subjects with measurements made in 1973, and we determined the distribution and possible interrelations with the UCP2 insertion/deletion (ins/del) polymorphism of these variables. We documented the BMI, glucose tolerance, and standard lipid variables in 1012 Tongan subjects (429 men and 583 women, ages 15 to 85 years) during 1998 and 2000 and compared the BMI findings with those of the 1973 survey. We also genotyped for the UCP2 ins/del polymorphism, assessed its association with obesity and type 2 diabetes, and compared its prevalence with those reported for other ethnic populations. The mean BMI ± SD was greatly increased in both men (30.2 ± 5.4 kg/m²) and women (33.8 ± 6.2 kg/m²), representing increases since 1973 of 11.9% and 19.4%, respectively. The genotype frequencies were 97% for the del/del genotype and 3% for the ins/del genotype; we found no ins/ins homozygotes. This distribution is strikingly different from those reported for white, South Indian, Pima Native‐American, and Asian populations (49 to 77% for del/del genotype). We conclude that there is a marked prevalence of obesity in Tonga, a prevalence that has increased since 1973. We also conclude that there is a unique, near‐uniform distribution of the UCP2 45‐bp ins/del polymorphism in Tongans. This may be the result of a founder effect and may be relevant to the prevalence of obesity and type 2 diabetes in Tonga.     

The natural history of homocystinuria due to cystathionine beta-synthase deficiency

An international questionnaire survey has been conducted to define better the natural history of homocystinuria due to cystathionine beta-synthase deficiency and permit evaluation of treatment. Data were compiled for 629 patients. Among patients not discovered by newborn screening, B6-responsive individuals on the average have significantly better mental capabilities (mean IQ, 79) than do B6-nonresponsive individuals (mean IQ, 57). Time-to-event curves are presented for the other major clinical abnormalities produced by this disease. Each occurred at significantly lower rates in untreated B6-responsive than in untreated B6-nonresponsive patients, as shown by the following examples: (1) dislocation of optic lenses (at age 10, chances of dislocation: 55% and 82%, respectively); (2) initial clinically detected thromboembolic events (at age 15, chances of having had such an event: 12% and 27%, respectively); (3) radiologic detection of spinal osteoporosis (at age 15, chances of such osteoporosis having been detected: 36% and 64%, respectively); and (4) mortality (at age 30, chances of not surviving: 4% and 23%, respectively). Methionine restriction initiated neonatally prevented mental retardation, retarded the rate of lens dislocation, and may have reduced the incidence of seizures. Pyridoxine treatment of late-detected B6-responsive patients retarded the rate of occurrence of initial thromboembolic events. Following 586 surgical procedures, 25 postoperative thromboembolic complications occurred, six of which were fatal. Reproductive histories were reported predominantly for B6-responsive patients. Living offspring of either men or women patients had few abnormalities. The evidence is inconclusive whether untreated maternal cystathionine beta-synthase deficiency leads to excessive fetal loss. Only 13% of patients detected in screening programs of newborns and classified as to B6-responsiveness were B6-responsive, compared to 47% among late-detected patients. Current screening programs that identify neonatal hypermethioninemia may be preferentially failing to detect B6-responsive patients.     

Development of <Emphasis Type="Italic">Cleruchoides noackae</Emphasis>, an egg-parasitoid of <Emphasis Type="Italic">Thaumastocoris peregrinus</Emphasis>, in eggs laid on different substrates,with different ages and post-cold storage

Cleruchoides noackae Lin and Huber (Hymenoptera: Mymaridae) is an egg parasitoid of Thaumastocoris peregrinus Carpintero and Dellapé (Hemiptera: Thaumastocoridae). The parasitism and development of C. noackae was studied in T. peregrinus eggs of different ages, laid on eucalyptus leaves or paper towel and stored at 5 °C. The emergence, sex ratio and development of C. noackae and hatched nymphs of T. peregrinus were evaluated. This parasitoid had an emergence rate higher than 60% from zero to one, one to two, and two to three-day old eggs and lower than 10% for those 3–4 and 4–5 days old. The female proportion was 78% and the egg-adult period for C. noackae was 19.5 days. The use of T. peregrinus eggs up to three days old, laid on paper towel and stored at 5 °C for 14 days did not affect the biological parameters of C. nockae and should be used for mass rearing of this parasitoid.     

Antenatal diagnosis of glutaric acidemia

Two pregnancies at risk for glutaric acidemia were monitored. In one, in which the fetus was not affected, glutaric acid was not detected in the amniotic fluid at amniocentesis (15 weeks) and the glutaryl-CoA dehydrogenase activity of cultured amniotic cells was normal. In the other, a marked elevation of glutaric acid in the amniotic fluid, together with deficiency of glutaryl-CoA dehydrogenase in amniotic cells, prompted termination of the pregnancy, and studies on the abortus confirmed the diagnosis of glutaric acidemia. Glutaric acidemia, is, thus, another inborn error of metabolism which can be diagnosed in utero.