Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0424605 (developmental delay)
 8,158 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Patients with the cerebrohepatorenal syndrome of Zellweger lack peroxisomes and certain peroxisomal enzymes such as dihydroxyacetone phosphate acyltransferase in their tissues. Deficiency of this enzyme, which is necessary for glycerol ether lipid synthesis, provides a biochemical method for recognizing patients with subtle manifestations of Zellweger syndrome and suggests the utility of exogenous ether lipid precursors as a therapeutic strategy for these children. We describe the results of glycerol ether lipid supplementation to two children, one with classic Zellweger syndrome and 9% of control fibroblast dihydroxyacetone phosphate acyltransferase activity, and one with mild facial manifestations, wide sutures, hypotonia, developmental delay, hepatomegaly, peripheral retinal pigmentation, and 50% of control fibroblast dihydroxyacetone phosphate acyltransferase activity. An increase in erythrocyte plasmalogen levels following therapy was clearly demonstrated in the milder patient, and neither patient showed evidence of toxicity. Evaluation of therapy by comparison to the usual clinical course of Zellweger syndrome was not helpful because of the variability and incomplete documentation of 90 previously reported cases. The literature survey did provide criteria for classic Zellweger syndrome, which include hypotonia with or without deformation of limbs, large fontanels and split sutures, prominent forehead, flattened facial profile with hypoplastic supraorbital ridges, anteverted nares, highly arched palate, cryptorchidism or labial hypoplasia, hepatomegaly or elevated liver enzymes, peripheral pigmentation of the retina, renal cortical cysts, and characteristic neuropathology involving decreased myelinization, abnormal neuronal migration, and sudanophilic macrophages. Less severe patients, as exemplified by our case 2 and others from the literature, will not have all the classic features and can be recognized only by a growing panel of biochemical indicators. Our patient studies illustrate the complexity of designing comprehensive therapy for Zellweger-like conditions, suggest other diseases that may involve peroxisomal alterations, and emphasize the need for multicenter, collaborative studies to evaluate biochemical heterogeneity and therapy of peroxisomal disorders.
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PMID:Zellweger syndrome: diagnostic assays, syndrome delineation, and potential therapy. 370 14

The peroxisomal disorders represent a group of inherited metabolic disorders that derive from defects of peroxisomal biogenesis and/or from dysfunction of single or multiple peroxisomal enzymes. We described earlier an 8 1/2 year-old with a history of progressive developmental delay, micronodular cirrhosis, and elevated very long chain fatty acids in plasma and skin fibroblasts. These findings were felt to be compatible with both neonatal adrenoleukodystrophy (nALD) and Zellweger syndrome (ZS). This patient is now 21 years old and his clinical course, inconsistent with either nALD or ZS, led us to examine his peroxisomal status in light of a possible new peroxisomal disease. The normal levels of bile acid precursors found in this patient suggest that peroxisomal beta-oxidation is functional. The activities of dihydroxyacetone phosphate acyltransferase and oxidation of lignoceric acid and phytanic acid were 14, 17, and 15% of the control, respectively. This partial activity for oxidation and the normal levels of bile acid precursors suggests that this patient has peroxisomes containing beta-oxidation enzymes. Western blot analysis of subcellular organelles showed that beta-oxidation enzyme proteins are present at normal levels in catalase-negative peroxisomes of density equivalent to normal peroxisomes. The presence of acyl-CoA oxidase and 3-ketoacyl-CoA thiolase in catalase-negative peroxisomes suggests that both peroxisomal targeting signal-1 (PTS-1), and peroxisomal targeting signal-2 (PTS-2)-mediated protein transport processes into peroxisomes are normal in this patient. These findings of catalase-negative peroxisomes of normal density and normal PTS-1 and PTS-2 import machinery with partial peroxisomal functions clearly demonstrate that this patient differs from those with known disorders of peroxisomal biogenesis.
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PMID:Biochemical features of a patient with Zellweger-like syndrome with normal PTS-1 and PTS-2 peroxisomal protein import systems: a new peroxisomal disease. 925 85

Infantile Refsum disease (IRD) is one of the less severe of Zellweger spectrum disorders (ZSDs), a group of peroxisomal biogenesis disorders resulting from a generalized peroxisomal function impairment. Increased plasma levels of very long chain fatty acids (VLCFA) and phytanic acid are biomarkers used in IRD diagnosis. Furthermore, an increased plasma level of phytanic acid is known to be associated with neurologic damage. Treatment of IRD is symptomatic and multidisciplinary.The authors report a 3-year-old child, born from consanguineous parents, who presented with developmental delay, retinitis pigmentosa, sensorineural deafness and craniofacial dysmorphisms. While the relative level of plasma C26:0 was slightly increased, other VLCFA were normal. Thus, a detailed characterization of the phenotype was essential to point to a ZSD. Repeatedly increased levels of plasma VLCFA, along with phytanic acid and pristanic acid, deficient dihydroxyacetone phosphate acyltransferase activity in fibroblasts and identification of the homozygous pathogenic mutation c.2528G>A (p.Gly843Asp) in the PEX1 gene, confirmed this diagnosis. Nutritional advice and follow-up was proposed aiming phytanic acid dietary intake reduction. During dietary treatment, plasma levels of phytanic acid decreased to normal, and the patient's development evaluation showed slow progressive acquisition of new competences.This case report highlights the relevance of considering a ZSD in any child with developmental delay who manifests hearing and visual impairment and of performing a systematic biochemical investigation, when plasma VLCFA are mildly increased. During dietary intervention, a biochemical improvement was observed, and the long-term clinical effect of this approach needs to be evaluated.
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PMID:Infantile Refsum Disease: Influence of Dietary Treatment on Plasma Phytanic Acid Levels. 2630 11