Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0019214 (hepatosplenomegaly)
 4,408 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In patients with Niemann-Pick disease type C (NPC), an autosomal recessive lipid storage disorder, neurodegeneration can occur in early life. Vertical ophthalmoplegia and extrapyramidal signs may be seen. Cholestatic jaundice and hepatosplenomegaly occur frequently in patients with early onset disease, with bone marrow biopsies showing diffuse infiltration of foamy histiocytes. Cholesterol esterification in skin fibroblasts is reduced, resulting in intracellular accumulation of cholesterol. NPC1 mutations are responsible for the disease in approximately 95% of patients. NPC1 encodes a 1278 amino acid protein which contains 13 transmembrane domains. Over 130 mutations have been identified in NPC1, with over a third present within an NPC1 specific cysteine-rich domain positioned in a large extracellular loop. It has been proposed that the defect in cholesterol homoeostasis is the cause of neuronal apoptosis, but the precise role of the NPC1 protein and the functional implications of its mutations remain unknown. Although NPC is routinely diagnosed by biochemical analysis, identification of molecular defects helps confirm the diagnosis and enables family studies, and rapid, accurate prenatal diagnosis. This report describe the analysis of the NPC1 gene in five Taiwanese/Chinese patients with NPC. Six novel NPC1 mutations (N968S, G1015V, G1034R, V1212L, S738Stop, and I635fs) were identified of which three are missense mutations located in the cysteine-rich domain. These are the first NPC1 mutations reported from Chinese patients with NPC.
 ...
PMID:Six novel NPC1 mutations in Chinese patients with Niemann-Pick disease type C. 1577 55

Human health in the past and presently is influenced by the amounts and proportion of chemical elements to which humans have been exposed. Arsenic, as a therapeutic agent was known to ancient Greeks and Romans. Ehrlick introduced organic arsenicals as anti linetic agents but with advent of penicillin these have nearly become obsolete. Once considered toxic, harmful to humans, arsenic is now considered an essential ultra trace element at least in animals. Now the impact of arsenic on health is more from industrial and environmental than medicinal exposure. This article reviews human exposure to arsenic in non occupational population, mostly through drinking water which is a worldwide problem, more so in south East Asia. Sources of arsenic, normal and abnormal levels in blood and tissues levels, old and new methods of estimation of arsenic, mechanism of action of arsenic in experimental animal is briefly reviewed. Old described clinical manifestation of arsenic in humans is briefly reviewed and newly described clinical manifestations in human with special emphasis on atherosclerosis, liver and diabetes are discussed. Proposed biological mechanisms in experimental animals included up regulation of inflammatory signals like cytokines and TNF-alpha, oxidative stress, hypomethylation, decreased DNA repair and apoptosis, cell proliferation, angiogenesis, activation of several enzymes like methyl transferase which converts inorganic arsenic to MMA and DMA, and GSH in in-vivo and in-vitro in experimental rat liver slices. Experimentally NAC (N-Acetyl Cysteine) treatment attenuates oxidative stress in atherosclerosis apoptosis and liver injury. GSH probably plays an important role in deactivation of the intermediate products of arsenic metabolism and prevents peroxidation of membrane lipids. Chronic human exposure has been linked to several systems in the human body: dermal (exfoliative dermatitis, keratosis, vitiligo, skin cancer), peripheral neuropathy, encephalopathy, bronchitis, pulmonary fibrosis, hepatosplenomegaly resembling NCPF, portal hypertension, peripheral vascular disease and BFD, arteriosclerosis and cancers of lung, urinary bladder, other internal organs and diabetes. Experimental and epidemiological evidence support diabetes effect of high level arsenic exposure. Low and moderate exposure to arsenic in drinking water is widely prevalent and may play a role in diabetes prevalence and needs to be studied further. Role of arsenic in Indian arteriosclerosis, diabetes and liver diseases, (cirrhosis, NCPF), need to be studied further. Study of mechanisms and enzymes mentioned need to be studied in humans exposed to arsenic and other xenobiotics. Measuring arsenic exposure, metabolic and biologic effects by newly described and simpler urine proteomics may accelerate our understanding of arsenic on health consequences.
 ...
PMID:Arsenicosis: review of recent advances. 2175 19

Multiple sulfatase deficiency is biochemically characterized by the accumulation of sulfated lipids and acid mucopolysaccharides. The gene sulfatase-modifying factor 1 (SUMF1), recently identified, encodes the enzyme responsible for post-translational modification of a cysteine residue, which is essential for the activity of sulfatases. We describe clinical findings and mutation analysis of four patients. The patients presented with hypotonia, developmental delay, coarse face, ichthyosis, and hepatosplenomegaly. The diagnosis was made through clinical findings, enzymatic assays, and mutation analysis. We were detected to be homozygous for a novel missense mutation c. 739G > C causing a p.G247R amino acid substitution in the SUMF1 protein.
...
PMID:Multiple sulfatase deficiency: A case series of four children. 2433 20

Acid sphingomyelinase (ASM) is a lysosomal hydrolase that degrades sphingomyelin into ceramide and phosphocholine. Recent crystallographic studies revealed the functional role of the N-terminal ASM saposin domain. ASM deficiency due to mutations in the ASM-encoding sphingomyelin phosphodiesterase 1 (SMPD1) gene causes an autosomal recessive sphingolipid-storage disorder, known as Niemann-Pick disease Type A (NPA) or Type B (NPB). NPA is an early-onset neuronopathic disorder, while NPB is a late-onset non-neuronopathic disorder. A homozygous one-base substitution (c.398G>A) of the SMPD1 gene was identified in an infant with NPA, diagnosed with complete loss of ASM activity in the patient's fibroblasts. This mutation is predicted to substitute tyrosine for cysteine at amino acid residue 133, abbreviated as p.C133Y. The patient showed developmental delay, hepatosplenomegaly and rapid neurological deterioration leading to death at the age of 3 years. To characterize p.C133Y, which may disrupt one of the three disulfide bonds of the N-terminal ASM saposin domain, we performed immunoblotting analysis to explore the expression of a mutant ASM protein in the patient's fibroblasts, showing that the protein was detected as a 70-kDa protein, similar to the wild-type ASM protein. Furthermore, transient expression of p.C133Y ASM protein in COS-7 cells indicated complete loss of ASM enzyme activity, despite that the p.C133Y ASM protein was properly localized to the lysosomes. These results suggest that the proper three-dimensional structure of saposin domain may be essential for ASM catalytic activity. Thus, p.C133Y is associated with complete loss of ASM activity even with stable protein expression and proper subcellular localization.
 ...
PMID:An Early-Onset Neuronopathic Form of Acid Sphingomyelinase Deficiency: A SMPD1 p.C133Y Mutation in the Saposin Domain of Acid Sphingomyelinase. 3194 52