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)

Niemann-Pick C (NP-C) is a fatal autosomal recessive storage disorder characterized by progressive neurodegeneration and variable hepatosplenomegaly. At the cellular level, cells derived from an affected individual accumulate unesterified cholesterol in lysosomes when cultured with low-density lipoprotein. The NP-C gene was identified at 18q11. The transcript is 4.9 kb encoding a 1278-amino-acid protein. We have defined the genomic structure of NPC1 along with the 5' flanking sequence. The NPC1 gene spans greater than 47 kb and contains 25 exons. Exons range in size from 74 to 788 bp with introns ranging in size from 0.097 to 7 kb. All intron/exon boundaries follow the GT/AG rule. The 5' flanking sequence has a CpG island containing multiple Sp1 sites indicative of a promoter region. The CpG island is located in the 5' flanking sequence, exon 1 and the 5' end of intron 1. We have also identified multiple single nucleotide polymorphisms in the coding and intronic sequences.
 ...
PMID:The genomic organization and polymorphism analysis of the human Niemann-Pick C1 gene. 1042 13

Niemann-Pick type C (NPC) disease is an autosomal recessive lipid-storage disorder usually characterized by hepatosplenomegaly and severe progressive neurological dysfunction, resulting from mutations affecting either the NPC1 gene (in 95% of the patients) or the yet-to-be-identified NPC2 gene. Our initial study of 25 patients with NPC1 identified a T3182-->C transition that leads to an I1061T substitution in three patients. The mutation, located in exon 21, affects a putative transmembrane domain of the protein. PCR-based tests with genomic DNA were used to survey 115 unrelated patients from around the world with all known clinical and biochemical phenotypes of the disease. The I1061T allele constituted 33 (14.3%) of the 230 disease-causing alleles and was never found in controls (>200 alleles). The mutation was particularly frequent in patients with NPC from Western Europe, especially France (11/62 alleles) and the United Kingdom (9/32 alleles), and in Hispanic patients whose roots were in the Upper Rio Grande valley of the United States. The I1061T mutation originated in Europe and the high frequency in northern Rio Grande Hispanics results from a founder effect. All seven unrelated patients who were homozygous for the mutation and their seven affected siblings had a juvenile-onset neurological disease and severe alterations of intracellular LDL-cholesterol processing. The mutation was not found (0/40 alleles) in patients with the severe infantile neurological form of the disease. Testing for this mutation therefore has important implications for genetic counseling of families affected by NPC.
 ...
PMID:Niemann-Pick C1 disease: the I1061T substitution is a frequent mutant allele in patients of Western European descent and correlates with a classic juvenile phenotype. 1052 Dec 97

Niemann-Pick type C (NP-C) disease is a progressive neurodegenerative disorder characterized by the inappropriate accumulation of unesterified cholesterol in lysosomes [1]. NP-C patients show various defects including hepatosplenomegaly, ataxia, dystonia and dementia. Most cases of NP-C are associated with inactivating mutations of the NPC1 gene [2], which encodes a protein implicated in the retrograde transport of sterols and other cargo from lysosomes [3]. Furthermore, localization of the NPC1 protein to lysosomal/endosomal compartments is essential for proper transport [4]. To create a model of NP-C disease in a simple, genetically tractable organism, we generated deletion mutations in two Caenorhabditis elegans homologs of the human NPC1 gene, designated npc-1 and npc-2. Animals mutant for npc-1 developed slowly, laid eggs prematurely, and were hypersensitive to cholesterol deprivation. Furthermore, npc-1; npc-2 double-mutant animals inappropriately formed dauer larvae under favorable growth conditions. These phenotypes in C. elegans provide a model system for both genetic and chemical suppressor screening that could identify promising drug targets and leads for NP-C disease.
 ...
PMID:A model for niemann-pick type C disease in the nematode Caenorhabditis elegans. 1080 41

Niemann-Pick type C disease is an autosomal-recessive, inherited neurovisceral lipid storage disorder. This disease results from either protein NPC1 or HE1 deficiency, which leads to cholesterol metabolism disturbance and is characterized by early hepatosplenomegaly and progressive ataxia, dystonia, cataplexy, dysarthria, and dementia. We describe a 3 1/2-year-old patient with Niemann-Pick type C disease, who presented with regression in both cognitive and motor domains. Almost 10 months before admission to the hospital, the child developed progressive speech and behavioral changes, as well as gait disturbances with frequent falls. The examination demonstrated hepatosplenomegaly, ataxia, and vertical gaze palsy. Nerve conduction velocities demonstrated mild demyelinating peripheral neuropathy. Bone marrow examination revealed foam cells, and cholesterol esterification studies found massive accumulation of unesterified cholesterol and very low intracellular esterification of exogenous lipoprotein-derived cholesterol. These results indicate Niemann-Pick type C disease. Peripheral neuropathy is a rare complication in patients with Niemann-Pick type C disease, which certainly contributes to their neurologic deterioration.
 ...
PMID:Niemann-Pick type C disease associated with peripheral neuropathy. 1462 10

Niemann-Pick disease type C (NP-C) is an autosomal recessive lipid-storage disease that is characterized by progressive neurodegeneration and hepatosplenomegaly. Since identification of the NPC1 gene in 1997, a total of 120 disease-causing mutations have been reported. In this study, two novel mutations were identified, namely c.2508[-2509]A del (837Fs-838X) in exon 16 and T3194G (V1065G) in exon 21. To explore the impact of NPC1 mutations on transcription of this gene, we analyzed NPC1 mRNA levels in skin fibroblasts derived from NP-C patients. Fibroblasts from patients with missense mutations showed increased levels of NPC1 mRNA while fibroblasts from patients with a specific frameshift mutation showed mRNA levels similar to those of normal control subjects. These results suggest that NPC1 transcription levels are altered in cells with mutations in the NPC1 gene.
 ...
PMID:Increased NPC1 mRNA in skin fibroblasts from Niemann-Pick disease type C patients. 1513 Jun 91

Niemann-Pick type C, or NPC for short, is an early childhood disease exhibiting progressive neurological degeneration, associated with hepatosplenomegaly in some cases. The disease, at the cellular level, is a result of improper trafficking of lipids such as cholesterol and glycosphingolipids (GSLs) to lysosome-like storage organelles (LSOs), which become engorged with these lipids. It is believed that the initial defect in trafficking, whether of cholesterol or a GSL, results in an eventual traffic jam in these LSOs. This leads to the retention of not only other lipids, but also of transmembrane proteins that transiently associate with the late endosomes (LE) in normal cells, on their way to other cellular destinations such as the trans-Golgi network (TGN). In this review, we discuss the biophysical properties of lipids and cholesterol that might determine their intracellular itineraries, and how these itineraries are altered in NPC cells, which have defects in the proteins NPC1 or NPC2. We also discuss some potential therapeutic directions being suggested by recent research.
 ...
PMID:Lipid and cholesterol trafficking in NPC. 1546 24

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

We present the third case of Niemann-Pick disease type C without neurological symptoms. The patient was a 53-year-old woman without significant prior health problems who died of acute pulmonary embolism. Autopsy findings of hepatosplenomegaly, lymphadenopathy and ceroid-rich foam cells raised the suspicion of the visceral form of acid sphingomyelinase deficiency (Niemann-Pick disease type B; NPB) or a much rarer disorder, variant adult visceral form of Niemann-Pick disease type C (NPC). To verify the histopathological findings, SMPD1, NPC1 and NPC2 genes were analysed. Two novel sequence variants, c.1997G>A (S666N) and c.2882A>G (N961S) were detected in the NPC1 gene. No pathogenic sequence variants were found either in the SMPD1 gene mutated in NPB or in NPC2 gene. The pathogenicity of both NPC1 variants was supported by their location in regions important for the protein function. Both variations were not found in more than 300 control alleles. Identified sequence variations confirm the diagnosis of the extremely rare adult visceral form of Niemann-Pick disease type C, which is otherwise dominated by neurovisceral symptoms. Although only three patients have been reported, this (most probably underdiagnosed) form of NPC should be considered in differential diagnosis of isolated hepatosplenomegaly with foam cells in adulthood.
 ...
PMID:Subclinical course of adult visceral Niemann-Pick type C1 disease. A rare or underdiagnosed disorder? 1680 7

Niemann-Pick type C (NP-C) disease is a neurovisceral lysosomal storage disease characterized by neurologic dysfunction, hepatosplenomegaly, and early death. Natural history studies are very difficult to perform due to the low incidence and high heterogeneity of disease in the human population. Sixteen cats with a spontaneously occurring missense mutation in NPC1 were evaluated over time to define the progression of neurologic and hepatic disease. Affected cats had remarkably regular onsets of specific signs of cerebellar and vestibular system dysfunction with progressive severity of dysfunction quantified by postrotatory nystagmus and brain stem auditory evoked response measures. NP-C disease cats also showed increasing serum activity of alanine aminotransferase, asparate aminotransferase, and cholesterol with advancing age. Affected cats lived to a mean age of 20.5 +/- 4.8 wk. CNS and hepatic lesions were similar to those described in human patients. These data are the first to document progressive hepatic disease in the feline model and demonstrate the importance of liver disease as part of the NP-C disease phenotype. Both neurologic and hepatic measures of disease onset and severity can be used as a baseline with which to assess the efficacy of experimental therapies of NP-C disease in the feline model.
 ...
PMID:Clinical, electrophysiological, and serum biochemical measures of progressive neurological and hepatic dysfunction in feline Niemann-Pick type C disease. 1861 65

Niemann-Pick, type C (NP-C) disease is an autosomal recessive neurovisceral storage disorder in which cholesterol and sphingolipids accumulate. There is no specific treatment for this disease, which is characterized by progressive neurological deterioration, sometimes accompanied by hepatosplenomegaly. We and others have shown that overexpression of certain Rab GTPases corrects defective membrane trafficking and reduces lipid storage in cultured NP-C fibroblasts. Here, we tested the possibility that Rab protein overexpression might also have beneficial effects in vivo using a murine model of NP-C. We first generated several lines of transgenic mice that ubiquitously overexpress Rab9 up to approximately 30-fold more than endogenous levels and found that the transgene expression had no obvious effects on fertility, behavior, or lifespan in normal mice. These transgenic strains were then crossed with NP-C mutant mice to produce NP-C homozygous recessive mice with and without the Rab9 transgene. Life expectancy of the NPC1 homozygous recessive animals was extended up to 22% depending on gender and the transgenic strain that was used. Histological studies and lipid analysis of brain sections indicated that the NP-C mice carrying the Rab9 transgene had dramatically reduced storage of GM(2) and GM(3) gangliosides relative to NP-C animals lacking the transgene. These results demonstrate that Rab9 overexpression has the potential to reduce stored lipids and prolong lifespan in vivo.
 ...
PMID:Development of a Rab9 transgenic mouse and its ability to increase the lifespan of a murine model of Niemann-Pick type C disease. 1905 48


1 2 3 Next >>