SummaryPrenatal diagnosis was requested by a family at risk for metachromatic leukodystrophy (MLD). An examination of the family leukocyte arylsulfatase A profile revealed that the mother had pseudo arylsulfatase A deficiency. Cultured amniotic fluid cells were deficient in arylsdfatase A, so two possibilities were indicated. the fetus was affected with MLD or had the pseudodeficiency phenotype. The only known biochemical test to differentiate the two enzyme deficient phenotypes is cerebroside sulfate loading of growing fibroblasts. The pseudodeficient cells hydrolyze the incorporated sulfatide as efficiently as control cells, whereas MLD cells show no hydrolysis. Application of this test to the at risk cultured amniotic fluid cells resulted in appreciable uptake of the sulfolipid, but no hydrolysis. Control amniotic fluid cell cultures hydrolyzed 82 to 95% of the incorporated sulfatide. Therefore, an affected fetus was indicated. Fibroblasts derived from the aborted fetus sbowed a deficiency of arylsulfatase A and a similar inability to hydrolyze cerebroside sulfate i n the loading test. The loading technique allowed the prenatal diagnosis of MLD when the arylsulfatase A analysis was equivocal. Speculation I n metachromatic leukodystrophy families with pseudo arylsulfatase A deficiency, the usual enzyme assays on cultured amniotic fluid cell extracts fail to differentiate between the fetus with the affected phenotype and the fetus with the pseudodeficiency phenotype. The cerebroside sulfate loading test in growing cultured amniotic fluid cells allowed this discrimination. I t is important to examine the family enzyme profile for the peudodeficiency phenotype as a prerequisite in the prenatal diagnosis of metachromatic leukodystrophy to avoid the erroneous identification of a pseudodeficient fetus as a metachromatic leukodystrophy fetus.In metachromatic leukodystrophy (MLD), the profound deficiency of arylsulfatase A (ajlsuifaie ~ulfohydrola&, EC 3.1.6.1) leads to the accumulation of cerebroside sulfate in neural tissue ~ resulting in progressive neurological degeneration (5). Based on the age of onset of symptoms, three classical types of MLD are recognized: late infantile, juvenile, and adult. Each type appears to be an independent autosomal recessive disorder, so allelism is implied. Although no treatment is available, the disorder can be prevented in at risk families because MLD is amenable to prenatal diagnosis. In affected pregnancies, cultured amniotic fluid cells are deficient in arylsulfatase A (10,14,17,(21)(22)(23)(24).Dubois el al. (3, 4). Lott el al. (15). and Fluharty el al. (8) described four MLD families in which one of the parents and some of the unaffected children had very low arylsulfatase A activities which overlapped the range of probands. These individuals showed no neurologic dysfunction and were healthy, so it would be appropriate to iypifi the apparent enzyme deficikncy as a ~seudodeficiencv. The attenuated enzyme activity was observed in' leukocyte anda fibroblast extracts khether thk ...
An investigation of NAD-NADH concentrations in the pancreatic islets of rats following diabetogenic doses (65 mg./kg.) of streptozotocin (SZ), given singly or in combination with nicotinamide or nicotinic acid, is reported. After a given treatment of the animals, the pancreases were surgically removed. The concentrations of NAD and NADH were determined on islets isolated from freeze-dried sections of the pancreas. In the pancreatic islets of untreated control animals, the mean ± S.E. concentrations of NAD and NADU were 1,122 ± 5 7 and 129 ± 28 mμnmoles/gm. dry tissue, respectively. The NAD content of the islets decreased to 27 per cent of the control value one hour and to 12 per cent five hours after administration of SZ. NADH concentration five hours after SZ was significantly reduced from the control value. When nicotinamide was given thirty minutes before SZ, the depletion of NAD associated with SZ administration was prevented. When nicotinamide was given one hour after SZ, the depressed NAD concentration observed at this time was subsequently raised. In contrast, nicotinic acid given thirty minutes prior to SZ did not prevent depletion of NAD. The data suggest that streptozotocin-induced betacell deterioration may be etiologically related to depletion of cellular NAD.
AN infant with mixed gonadal dysgenesis was found to have a 45,X/46,Xpsu dic(Y) karyotype. A low level (8%) of mosaicism for the dic(Y) cell line was observed in peripheral blood lymphocytes and skin fibroblasts. The dicentric nature of the Y chromosome became apparent in fluorescence in situ hybridization studies. The presence of Y centromeric sequences was demonstrated in the paraffin-embedded testis and streak ovary sections. The ration of Y-positive cells was higher in the testis than in the streak ovary.
An infant with clinical features of Potterand Turner syndromes at birth was found to have a translocation of a portion of the long arm of a Y chromosome to a 21 chromosome, and only one X chromosome. The infant had bilateral dysplastic kidneys and hypoplastic lungs and suffered spontaneous rupture of the heart and pneumothoraces. Except for gonads with persistent sex cords and a solitary degenerating follicle, the genital organs were female. The sexual differentiation is compatible with the theory that the short arm of the Y chromosome is mainly responsible for male differentiation but implies that the long arm is not without effect on gonadal development. The occurrence of severe renal abnormalities in an infant with a sex chromosome abnormality may be more than coincidental.The association of pulmonary hy¬ poplasia with bilateral renal agen¬ esis was noted by Potter in 1946. ' In 1960, Bain and Scott described similar pulmonary hypoplasia with other se¬ vere renal abnormalities, mainly bi¬ lateral cystic dysplasia and severe congenital obstructions.2 Stern et al emphasized that as a result of the se¬ vere pulmonary hypoplasia, many of these infants had pneumothorax and pneumomediastinum.3 In all series, there has been a preponderance of males. Renal anomalies are common in XO Turner syndrome.46 We report the occurrence of bilateral renal dysgenesis, pulmonary hypoplasia and bilateral pneumothoraces, and spontaneous rupture of the heart in
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.