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Query: UMLS:C0025362 (mental retardation)
 15,878 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Case report of a 18 year old boy with short stature, microceophaly, mental retardation and multiple dysmorphic signs. At the age of 9 years a severe generalised osteoporosis was discovered. A pathological fracture of the greenwoor type healed without proper callus formation. The osteoporosis persists without signs of either deterioration or improvement. The serum phosphorus is slightly decreased, while serum calcium, alkaline phosphatase and renal functions are normal. The main biochemical finding is a constant hyperclaciuria of 6-13 mg/kg/24 h, which can be corrected by treatment with oral sodium phosphate. No other chronic disease could be found which would explain the bone disease. The complex disease of this boy does not fit into the known pictures of osteogenesis imperfecta, idiopathic juvenile osteoporosis or of idiopathic hypercalciuria, and might therefore be another type of demineralising bone disease. It is suggested, that the cause might be an impairment of the calcium fixation of collagen fibres during desmal ossification.
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PMID:[Uncommon form of idiopathic osteoporosis with hypercalciuria, growth retardation and mental retardation]. 115 69

We report a case of HAM/TSP presenting with short stature, mental retardation, skin eruptions, uterine and ovarian hypogenesis and nephropathy. Skin erythema was noted since from the age of three years old and spasticity of lower extremities from elementary school age. Serum calcium level showed 4.1 mEq/l. Recombinant human PTH infusion resulted in no response of phosphate excretion. The persistent proteinuria prompted renal needle biopsy, which revealed IgA and C1q deposits in glomerular mesangium. A diagnosis of pseudohypoparathyroidism and IgA nephropathy was entertained. This patient with pseudohypoparathyroidism who has a deficient immune system was seized with the early onset of HAM/TSP and IgA nephropathy.
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PMID:A case of HTLV-I-associated myelopathy with IgA nephropathy and pseudohypoparathyroidism type 1. 179 21

In 1930 adenosine triphosphate appeared in the literature from W. A. Engelhardt's work on avian erythrocytes. This was an early example of oxidative phosphorylation in intact cells, and it required methylene blue and oxygen. Both Belitser and I realized that the use of Warburg manometers for aeration was critical in order to generate oxidative phosphorylation of glucose in tissue preparations. Test tube techniques did not work. In 1956 we were able to describe a human type of diabetes called "galactose diabetes," in which consumption of human or cows' milk provokes mental retardation. Replacement of human or cows' milk products with "vegetable milk" formula in early infancy can prevent retardation. We determined that the disease results from a defect of galactose-one-phosphate uridylyl-transferase, a hereditary enzyme. This type of enzyme defect, if discovered and treated in early infancy, is a benign molecular disease. Regulation of transport systems in mammalian cell cultures are frequently complex energized systems. Perhaps my greatest surprise in this regard was the mere fact that an all-cis "odd" hexose-D-allose turned out to be a highly intense down-regulator of the hexose transport system. Additions of inhibitors of oxidative phosphorylation (such as oligomycin or di-nitrophenol) arrested the allose-mediated down-regulation. We have reason to suspect that the strong down-regulator is a phosphorylated form of D-allose. Thus ends my story about oxidative energized biological phosphorylation systems.
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PMID:50 years of biological research--from oxidative phosphorylation to energy requiring transport regulation. 188 94

We describe the molecular characterization of two mutations responsible for galactosemia, an inherited disorder of galatose metabolism that causes jaundice, cataracts, and mental retardation in humans. The coding region of galactose-1-phosphate uridylyltransferase (GALT; UDPglucose:alpha-D-galactose-1-phosphate uridylyltransferase, EC 2.7.7.12) was amplified by the polymerase chain reaction from total cDNA of a classic galactosemic individual and was characterized by direct sequencing of the products. Two missense mutations were identified: (i) replacement of valine-44 by methionine and (ii) replacement of methionine-142 by lysine. These mutations led to a drastic reduction in GALT activity when individual mutant cDNAs were overexpressed in a mammalian cell system, although full-length protein is synthesized in this assay. The two galactosemia mutations account for 3 of the 15 galactosemia alleles analyzed. These results suggest that galactosemia is caused by a variety of mutations, which might be responsible for the observed clinical heterogeneity of this disorder. We also present the molecular characterization of two GALT polymorphisms: (i) replacement of leucine-62 by methionine and (ii) replacement of asparagine-314 by aspartate. It appears that galactosemia mutations tend to occur in regions that are highly conserved throughout evolution while the polymorphisms change variable residues.
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PMID:Molecular basis of galactosemia: mutations and polymorphisms in the gene encoding human galactose-1-phosphate uridylyltransferase. 201 74

Morphological changes are shown in the muscle biopsy specimens of an 8-year-old girl who suffered from a triosephosphate isomerase (TPI) deficiency, resulting in a chronic, nonspherocytic, hemolytic anemia, mental retardation and neuromuscular impairment. The newly introduced enzyme histochemical reaction for TPI demonstrated a total lack of histochemically detectable enzyme activity, whereas biochemical analysis of muscle tissue revealed less than 10% of the normal enzyme activity. Electron microscopy showed a degenerative myopathy with an increase in the amount of intracellular glycogen. Additionally, mitochondrial changes within the muscle fibers were observed to be similar to those in mitochondrial myopathies. The disturbed balance between glycerin-aldehyde phosphate and dihydroxyacetone phosphate, due to the deficiency of the TPI enzyme, is interpreted as the biochemical background of an impaired electron transport across the mitochondrial membrane, resulting in the coexistence of an impaired glycolytic pathway and an impaired mitochondrial metabolism of muscle cells.
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PMID:Myopathy with altered mitochondria due to a triosephosphate isomerase (TPI) deficiency. 233 91

Lowe (oculocerebrorenal) syndrome (LS) is an X-linked disorder characterized by congenital cataracts, generalized hypotonia, mental retardation, and renal Fanconi syndrome. The basic defect remains unknown, but the possibility that fibroblasts express reduced sulfation of glycosaminoglycans has been studied in several laboratories. A mechanism involving overproduction of an enzyme (nucleotide pyrophosphatase) active against adenosine 3'-phosphate, 5'-phosphosulfate (PAPS) has been postulated. Decreased synthesis of normally sulfated glycosaminoglycans was also reported. We measured the synthesis of proteoglycans and glycosaminoglycans by incorporation of [3H]glucosamine and Na2(35)SO4 into cultured fibroblasts from four LS patients and related it directly to the synthesis in six normal fibroblast cultures. We found that the rate of synthesis varied greatly among the normal cultures (cv, 30%), but not significantly between LS and the normal. The LS fibroblasts' ability to sulfate glycosaminoglycans was assayed as the amount of 3H-glycosaminoglycan eluting at low ionic strength on anion exchange chromatography, the amount of non-sulfated disaccharide present in chondroitinase digests of labeled proteoglycans, and the ratio of 35S to 3H incorporation into proteoglycans. Each parameter suggested that the LS cells were synthesizing normally sulfated glycosaminoglycans (e.g. % delta Di-0S, 21 +/- 6 in normal; 27 +/- 6 in LS). The cells' ability to sulfate glycosaminoglycans was tested under conditions of markedly stimulated glycosaminoglycan synthesis, by treating the cultures with a beta-D-xyloside. LS and normal cells responded to the treatment by elevating the rate of synthesis of normally sulfated glycosaminoglycans (3.5-6-fold in normal, 3-7-fold in LS). Nucleotide pyrophosphatase activities were found to be elevated in each of our four LS cell strains as in the previous studies, excluding genetic heterogeneity as an explanation for our findings. We conclude that LS fibroblasts do not express defects in sulfation of glycosaminoglycans or in synthesis of proteoglycans.
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PMID:Proteoglycan synthesis in normal and Lowe syndrome fibroblasts. 357 Dec 27

A five-year-old girl was referred to prometaphase chromosome analysis because of mental retardation, facial dysmorphic features suggestive of Cornelia de Lange syndrome, cleft palate and additional minor congenital malformations of the cardiac system and fingers and toes. A familial balanced translocation (3;9)(q26.1; p23) was found. The karyotype of the proposita was 46,XX,der(9),t(3;9)(q26.1;p23). Thus the patient was trisomic for 3q26.1-qter and monosomic for 9p23-pter. The unbalanced chromosome constitution was not detected by standard Q-banding analysis shortly after birth. The karyotype was misdiagnosed as 46,XX,9(p+) in the proposita and her mother, and thought to be a normal variant of chromosome 9. The repeated cytogenetic study led to the diagnosis of the translocation and to the possibility of prenatal diagnosis in the translocation carriers. A survey of 22 published cases of dup(3q) showed that nearly 60% were secondary to familial balanced rearrangements with an excess of maternally derived abnormal chromosomes 3. Red blood cell galactose-1-phosphate-uridyltransferase (GALT) activity was normal in the patient, consistent with previous assignment of the gene locus for GALT to 9p13 (Shih et al. 1982).
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PMID:Partial trisomy 3q syndrome inherited from familial t(3;9)(q26.1; p23). 365 93

We report two cases duplication of 9p. This investigation was prompted by the identification of two patients with minor congenital anomalies and mental retardation. Chromosomal karyotype in both patients revealed 9p duplication, one as a result of tandem duplication of 9p at band p13 leads to p24 and the other due to an extra and deleted chromosome number 9 (pter leads to cent leads to q13). Both patients has elevated galactose-1-phosphate-uridyl-transferase level demonstrating additional evidence for mapping GALT on the short arm of chromosome 9.
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PMID:9p duplication confirmed by gene dosage effect: report of two patients. 697 7

Relationship of antiepileptics to serum alkaline phosphatase (ALP), serum calcium (Ca) and inorganic phosphate (P) were studied in 172 epileptic patients treated with antiepileptics for clarifying the related factors to produce osteomalacia following antiepileptics administration. Laboratory findings of ALP, Ca, and P were compared with normal value and determined as abnormal by exceeding the normal limit (mean +2SD (ALP), mean-2SD (Ca, P)). The following results were obtained: 1) In the 172 patients, 20 cases (11.6%) showed abnormal value of ALP, 12 cases (7.0%) of Ca and 41 cases (23.8%) of P (Single abnormal groups). On the other hand, 47 cases (27.3%) were found abnormal in two or three of ALP, Ca and P (Combined abnormal group). The rest 52 cases (30.2%) of the patients showed all normal value (Normal group). 2) Abnormal value of ALP and/or Ca were observed mostly before 20 years of age. The patients with abnormal P were more distributed in age than others. 3) The earlier and/or the longer administration of antiepileptics is prone to produce the more abnormal value. 4) Acetazolamide, metharbital, primidone, carbamazepine and mephobarbital were more used in combined group than in normal group, and polypharmaceutical use of these antiepileptics was supposed to be related to the abnormality of ALP, Ca and P. There was no different use of diphenyl-hydantoin and phenobarbital in frequency and amount between combined group and normal group. 5) Mental retardation and epileptic personality changes were observed more frequently in combined abnormal group than in normal group. 6) No significant relations were observed between clinical seizure types, seizure frequencies and abnormal laboratory findings.
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PMID:[Changes in serum levels of alkaline phosphatase, calcium, and inorganic phosphate following antiepileptic therapy (author's transl)]. 732 19

A new variant of glucosephosphate isomerase (GPI) associated with hemolytic anemia, mental retardation, and muscular hypotonia is described. The defective enzyme showed increased affinity for fructose-6-phosphate (F-6-P), decreased affinity for glucose-6-phosphate (G-6-P) altered electrophoretic and isoelectrofocusing patterns, and shift to the left of the precipitin curve. The enzyme was stable under all the conditions tested (heat, urea, guanidine-HCl, and storage). Optimum pH, Ki for 6-phosphogluconic acid (6-PGA) and for erythrose-4-phosphate (E-4-P), molecular weight, GPI-related antigen concentration, immunodiffusion pattern, and immunoinactivation were in the normal range. This is the first example of the association of a stable mutant GPI with severe hemolytic anemia. Enzyme instability has been present in all previously reported cases.
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PMID:The first stable variant of erythrocyte glucose-phosphate isomerase associated with severe hemolytic anemia. 743 96


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