Partial trisomy 17q

Summary A 15-year-old deeply mentally retarded male is described with partial distal 17q trisomy (17q2217qter), as the result of a de novo 17q/21p translocation. Differential Ag-staining showed that the satellites of chromosome 21 were included in the translocation chromosome.     

Partial trisomy of the short arm of chromosome 3 (3p25→3pter)

Summary Two profoundly mentally mentally retarded brothers with partial trisomy for the distal part of the short arm of chromosome 3 (3p253pter) are described. Their anomaly arose as a segregation product of a balanced t(3p-;18q+) translocation in the mother. Compared with the other cases of partial 3p trisomy reported up to now, the present patients display a similar craniofacial dysmorphism with hypertelorism, broad nasal tip, short upper lip with prominent philtrum, and a large mouth with down-turned corners. Other stigmata, such as a prominent, high forehead with frontal bossing and full cheeks, were present during childhood but progressively disappeared.     

The Nuclear Receptor Resource: a growing family.

Last year, the original Glucocorticoid Receptor Resource was expanded into a comprehensive project: the Nuclear Receptor Resource (NRR, http:// nrr.georgetown.edu/nrr/nrr.html ). The NRR has since been offering comprehensive information on nuclear receptor structure and function, as well as general facts of interest to the scientific community on meetings, funding and employment opportunities. The project now includes individual resources as part of a network which integrates information on glucocorticoid, androgen, mineralocorticoid, thyroid hormone, Vitamin D and peroxisome-proliferator activated receptors. Many investigators have joined the NRR network by filling the Who is who? form available in the NRR home page. This has facilitated communication among scientists in the field and dissemination of data nor otherwise published. Because several investigators have contacted NRR authors over the past few months asking for advice and materials for educational purposes, we have recently decided to include in our project an educational resource on nuclear receptors termed the 'Graphics Library'. The input and suggestions of NRR users do shape the future direction of the project, so we encourage user to give us feedback.     

Proximal trisomy 13q and distal monosomy 8p in a dysmorphic and mentally retarded patient with an isodicentric chromosome 13q and a 13q/8p translocation chromosome

A 40 year-old dysmorphic and mentally retarded female is reported with a de novo unbalanced chromosomal rearrangement (karyotype: 46,XX,der(8)t(8;13)(p23;q123),idic(13)(pter-->q123: q123-->pter) resulting in an isodicentric chromosome 13 and a double aneusomy including partial trisomy 13 (13pter-q123) and distal monosomy 8p (8pter-p23). The main clinical findings consist of developmental/mental retardation, behavioural disturbances and minor congenital defects, not consistent with the clinical pattern of either of the two aneusomies. A mechanism for the chromosome rearrangement is proposed and the absence of specific physical findings in the present patient is discussed in the light of the available literature data.     

Fatness and Physical Fitness of Girls 7 to 17 Years

A two-fold approach was used to investigate the association between fatness and fitness of girls 7 to 17 years of age: first, age-specific correlations between fatness and measures of health-related and motor fitness, and second, comparisons of fitness levels of girls classified as fat and lean. A representative sample of 6700 between 7 to 17 years was surveyed. Adiposity (fatness) was estimated as the sum of five skinfolds (biceps, triceps, subscapular, suprailiac, medial calf). Physical fitness included health-related items (step test, PWC₁₇₀ the sit and reach, sit-ups and leg lifts, flexed arm hang) and motor performance items (standing long jump, vertical jump, arm pull strength, flamingo stand, shuttle run, plate tapping). Age-specific partial correlations between fatness and each fitness item, controlling for stature and weight, were calculated. In addition, in each age group the fattest 5% (presumably the obese) and the leanest 5% were compared on each fitness test. After controlling for stature and weight, subcutaneous fatness accounts for variable percentages of the variance in each fitness item. Estimates for health-related fitness items are: cardiorespiratory endurance - step test (3% to 5%) and PWC₁₇₀ (0% to 16%), flexibility - sit and reach (3% to 8%), functional strength - flexed arm hang (6% to 17%) and abdominal strength - sit-ups/leg lifts (1% to 8%). Corresponding estimates for motor fitness items are more variable: speed of limb movement -plate tapping (0% to 3%), balance - flamingo stand (0% to 5%), speed and agility - shuttle run (2% to 12 %), static strength - arm pull (4% to 12%), explosive strength - standing long jump/vertical jump (11% to 18%). At the extremes, the fattest girls have generally poorer levels of health-related and motor fitness.     

Severe midline fusion defects in a newborn with 10q26----qter deletion

In this report we describe a male newborn with a severe midline fusion syndrome associated with a "pure" distal 10q deletion (del(10)(q26.1----qter].     

Molecular analysis of the isochromosome 12P in the Pallister-Killian syndrome

Summary An iso 12p chromosome from a patient with Pallister-Killian syndrome was successfully transferred into a mouse background by microcell-mediated chromosome transfer. The presence of the i(12p) chromosome was confirmed by karyotyping and by Southern blotting using five 12p and seven 12q probes. The isochromosome nature of the marker chromosome was confirmed by co-hybridization of a 12p probe with a 12q and an 8q probe. This cell line should be a valuable tool for physical mapping of 12p-derived DNA fragments; at the same time, it confirms the identity of the extra chromosome in the Pallister-Killian syndrome as i(12p).     

D-xylulose-induced depletion of ATP and Pi in isolated rat hepatocytes

Xylitol is known to cause hepatic ATP catabolism by inducing the trapping of Pi in the form of glycerol 3-P as a consequence of an increase in the NADH:NAD+ ratio, resulting from the oxidation of xylitol to D-xylulose. The question was therefore raised whether D-xylulose also depletes hepatic ATP. In isolated rat hepatocytes, 5 mM D-xylulose decreased ATP by 80% within 5 min compared to 40% with 5 mM xylitol. Intracellular Pi decreased by 70% within the same time interval with both compounds, but was restored three-fold faster with D-xylulose. The rate of utilization of D-xylulose reached 5 mumol.min-1.g-1 of cells, as compared with 1.5 for xylitol, indicating that reduction of xylitol into D-xylulose is a rate-limiting step in the metabolism of the polyol. D-Xylulose barely modified the concentration of glycerol 3-P but increased xylulose 5-P from 0.02 to 0.5 mumol/g within 5 min. The main cause of the ATP- and Pi-depleting effects of D-xylulose was found to be an accumulation of sedoheptulose 7-P from a basal value of 0.1 to 5 mumol/g of cells after 10 min. Ribose 5-P increased from 0.03 to 0.5 mumol/g at 5 min. Ribose 1-P also accumulated, albeit outside of the cells. This extracellular accumulation can be explained by the release of intracellular purine nucleoside phosphorylase from damaged hepatocytes acting on inosine that had diffused out of the cells. Smaller increases in the concentrations of sedoheptulose 7-P and pentose phosphates were recorded after incubations of the cells with xylitol.