Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0011849 (diabetes)
 277,896 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Like most essential nutrients, Fe needs to be maintained in the body at a defined level for optimal health, with appropriate adaptation to varying Fe needs and supply. The primary mechanism for controlling Fe level is the regulation of Fe absorption. Several different proteins have been identified as contributors to the process. Despite a complex regulatory system, Fe disorders (both Fe deficiency and Fe overload) occur. Fe deficiency is a common problem worldwide, resulting from inadequate dietary Fe and blood loss. Complications include pre-term labour, developmental delay, and impaired work efficiency. No specific genetic syndromes causing isolated Fe deficiency have been described, but animal studies and clinical observations suggest that such a relationship may be a possibility. Conversely, the known causes of Fe overload are genetic. Fe overload is less common than Fe deficiency, but can result in serious medical complications, including cirrhosis, primary liver cancer, diabetes, cardiomyopathy and arthritis. The most common and best characterized syndrome of Fe overload is hereditary haemochromatosis (HHC), an autosomal recessive disorder. Mutations in the HFE protein cause HHC, but the clinical presentation is variable. Of particular interest is the factor that some FIFE genotypes appear to be associated with protection from Fe deficiency. Other genetic variants in the regulatory pathway may influence the likelihood of Fe deficiency and Fe overload. Studies of genetic variants in HFE and other regulatory proteins provide important tools for studying the biological processes in Fe regulation. This work is likely to lead to new insights into Fe disorders and potentially to new therapeutic approaches. It will not be complete, however, until coordinated study of both genetic and nutritional factors is undertaken.
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PMID:Iron deficiency and iron overload: effects of diet and genes. 1131 Apr 26

We have identified a novel, maternally expressed imprinted gene encoding a C/D-box small nucleolar RNA (snoRNA) called MBII-343, which may regulate RNA editing or alternative splicing of an as yet unknown target gene. This gene is closely linked to an imprinted gene, Meg3, on mouse distal chromosome 12, which is syntenic to human chromosome 14. The paternal duplication of mouse distal chromosome 12 leads to late embryonal/neonatal lethality, growth promotion, and cardiomyopathy, whereas maternal duplication leads to late embryonal lethality and growth retardation. Human paternal uniparental disomy for chromosome 14 leads to musculoskeletal problems and mental retardation, whereas maternal uniparental disomy leads to intrauterine growth retardation, motor developmental delay, premature puberty, hypotonia, joint laxity, macrocephaly, short statue, neonatal poor sucking, skill with jigsaw puzzles, skin picking, obesity, and maturity onset diabetes of the young.
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PMID:Imprinting of a small nucleolar RNA gene on mouse chromosome 12. 1194 78

Except for the hyperinsulinism associated with the infant of a diabetic mother (accounting for about 5 percent of NICU admissions annually), pancreatic disorders of the newborn are rare. Congenital anomalies (such as annular pancreas) and endocrine disorders (such as hyperinsulinism of nesidioblastosis or hyperglycemia of neonatal diabetes mellitus) present many challenges to the personnel caring for these infants and their families. The potential mortality and morbidity of these disorders make it imperative for nurses and nurse practitioners working with infants to recognize and understand pancreatic dysfunction so that appropriate and timely intervention can prevent complications of brain injury and developmental delay. The home care needs of these infants and the extensive teaching needs of their parents require skilled nursing care to ensure a safe discharge.
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PMID:Pancreatic disorders in the newborn. 1194 98

In the fruit fly Drosophila, four insulin genes are coexpressed in small clusters of cells [insulin-producing cells (IPCs)] in the brain. Here, we show that ablation of these IPCs causes developmental delay, growth retardation, and elevated carbohydrate levels in larval hemolymph. All of the defects were reversed by ectopic expression of a Drosophila insulin transgene. On the basis of these functional data and the observation that IPCs release insulin into the circulatory system, we conclude that brain IPCs are the main systemic supply of insulin during larval growth. We propose that IPCs and pancreatic islet beta cells are functionally analogous and may have evolved from a common ancestral insulin-producing neuron. Interestingly, the phenotype of flies lacking IPCs includes certain features of diabetes mellitus.
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PMID:Ablation of insulin-producing neurons in flies: growth and diabetic phenotypes. 1200 30

Bardet-Biedl syndrome (BBS) is a pleiotropic genetic disorder with the cardinal features of obesity, photoreceptor degeneration, polydactyly, hypogenitalism, renal abnormalities, and developmental delay. Other associated clinical findings in BBS patients include diabetes, hypertension, and congenital heart defects. The clinical diagnosis is based on the presence of at least four of the cardinal symptoms. BBS is recognized to be a genetically heterogeneous autosomal recessive disorder mapping to eight known loci. Positional cloning and candidate gene evaluation have resulted in the identification of six BBS genes. Mutation of one of these genes, BBS6, also causes McKusick-Kaufman syndrome. The BBS6 gene is predicted to code for a protein with sequence similarity to the chaperonin family of proteins. The predicted BBS1, BBS2, BBS4, BBS7, and BBS8 gene products do not seem to be molecular chaperones, on the basis of a lack of sequence similarity to the chaperonin family of proteins. The identification of BBS8 suggests a possible role in cilia function for BBS gene products. It remains to be determined whether the multiple BBS proteins are part of a multisubunit complex or do not directly interact with each other but are part of a common pathway. The study of BBS illustrates the value of using isolated inbred populations for the study of human genetic diseases and suggests strategies for facilitating the study of complex diseases and traits.
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PMID:Use of isolated populations in the study of a human obesity syndrome, the Bardet-Biedl syndrome. 1515 61

Persistent hypoglycemia in the neonate is most often caused by hyperinsulinemia. Recent discoveries in the molecular and biochemical regulation of insulin secretion have increased dramatically our understanding of disorders responsible for syndromes of hyperinsulinemic hypoglycemia. This article focuses on defects and disorders of the KATP channel, activating mutation of glucokinase and glutamate dehydrogenase, and other disorders that may be associated with specific phenotypes to permit appropriate targeted therapies. It is essential to evaluate these entities carefully because of the emerging evidence that at least half, if not more, have focal disease, which can be cured by local excision rather than diffuse disease, which may not be cured even after near total pancreatectomy with risk for future diabetes. Delay in diagnosis may be associated with developmental delay. The mechanisms of hypoglycemia remain incompletely understood.
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PMID:Differential diagnosis and management of neonatal hypoglycemia. 1515 93

Permanent neonatal diabetes mellitus (PNDM) is a rare condition characterized by severe hyperglycemia constantly requiring insulin treatment from its onset. Complete deficiency of glucokinase (GCK) can cause PNDM; however, the genetic etiology is unknown in most PNDM patients. Recently, heterozygous activating mutations of KCNJ11, encoding Kir6.2, the pore forming subunit of the ATP-dependent potassium (K(ATP)) channel of the pancreatic beta-cell, were found in patients with PNDM. Closure of the K(ATP) channel exerts a pivotal role in insulin secretion by modifying the resting membrane potential that leads to insulin exocytosis. We screened the KCNJ11 gene in 12 Italian patients with PNDM (onset within 3 months from birth) and in six patients with non-autoimmune, insulin-requiring diabetes diagnosed during the first year of life. Five different heterozygous mutations were identified: c.149G>C (p.R50P), c.175G>A (p.V59M), c.509A>G (p.K170R), c.510G>C (p.K170N), and c.601C>T (p.R201C) in eight patients with diabetes diagnosed between day 3 and 182. Mutations at Arg50 and Lys170 residues are novel. Four patients also presented with motor and/or developmental delay as previously reported. We conclude that KCNJ11 mutations are a common cause of PNDM either in isolation or associated with developmental delay. Permanent diabetes of non autoimmune origin can present up to 6 months from birth in individuals with KCNJ11 and EIF2AK3 mutations. Therefore, we suggest that the acronym PNDM be replaced with the more comprehensive permanent diabetes mellitus of infancy (PDMI), linking it to the gene product (e.g., GCK-PDMI, KCNJ11-PDMI) to avoid confusion between patients with early-onset, autoimmune type 1 diabetes.
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PMID:KCNJ11 activating mutations in Italian patients with permanent neonatal diabetes. 1558 May 58

Inwardly rectifying potassium channels (Kir channels) control cell membrane K(+) fluxes and electrical signaling in diverse cell types. Heterozygous mutations in the human Kir6.2 gene (KCNJ11), the pore-forming subunit of the ATP-sensitive (K(ATP)) channel, cause permanent neonatal diabetes mellitus (PNDM). For some mutations, PNDM is accompanied by marked developmental delay, muscle weakness, and epilepsy (severe disease). To determine the molecular basis of these different phenotypes, we expressed wild-type or mutant (R201C, Q52R, or V59G) Kir6.2/sulfonylurea receptor 1 channels in Xenopus oocytes. All mutations increased resting whole-cell K(ATP) currents by reducing channel inhibition by ATP, but, in the simulated heterozygous state, mutations causing PNDM alone (R201C) produced smaller K(ATP) currents and less change in ATP sensitivity than mutations associated with severe disease (Q52R and V59G). This finding suggests that increased K(ATP) currents hyperpolarize pancreatic beta cells and impair insulin secretion, whereas larger K(ATP) currents are required to influence extrapancreatic cell function. We found that mutations causing PNDM alone impair ATP sensitivity directly (at the binding site), whereas those associated with severe disease act indirectly by biasing the channel conformation toward the open state. The effect of the mutation on ATP sensitivity in the heterozygous state reflects the different contributions of a single subunit in the Kir6.2 tetramer to ATP inhibition and to the energy of the open state. Our results also show that mutations in the slide helix of Kir6.2 (V59G) influence the channel kinetics, providing evidence that this domain is involved in Kir channel gating, and suggest that the efficacy of sulfonylurea therapy in PNDM may vary with genotype.
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PMID:Molecular basis of Kir6.2 mutations associated with neonatal diabetes or neonatal diabetes plus neurological features. 1558 26

CHARGE association (CA) consists of a non-random association of ocular coloboma (C), heart anomaly (H), atresia of choanae (A), retarded growth and/or development (R), genital hypoplasia (G), and ear anomalies and/or hearing impairment (E). A prospective multidisciplinary study of 31 Swedish patients with CA was undertaken in order to describe the associated malformations and functional deficits, find possible etiological factors and identify critical time periods for the maldevelopment. The clinical files were analyzed, the mothers answered a questionnaire on history of prenatal events, and a clinical evaluation of systemic findings, vision, hearing, balance, speech, oral and swallowing function, and neuro-psychiatric function, especially autism, was performed. The most frequent physical abnormalities affected ears (90%), eyes (90%), brain (61%), heart (52%), retarded growth (48%), genitals (38%), choanae (35%), and facial nerve (32%). Sixty-one percent of the patients were visually impaired or blind, and 74% had hearing loss or deafness. Problems in balance, speech, and eating were common. Forty percent of the patients had autism/atypical autism, and 82% had developmental delay. Three children were born following assisted fertilization and two mothers had diabetes. The mothers reported infections, bleedings, and drug use during pregnancy. Analysis of possible critical time periods suggested that most malformations were produced early in pregnancy, mainly during post conceptual weeks 4, 5, and 6. A multidisciplinary approach is essential in the assessment and management of CA.
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PMID:CHARGE association in Sweden: malformations and functional deficits. 1563 80

Neonatal diabetes can either remit and hence be transient or else may be permanent. These two phenotypes were considered to be genetically distinct. Abnormalities of 6q24 are the commonest cause of transient neonatal diabetes (TNDM). Mutations in KCNJ11, which encodes Kir6.2, the pore-forming subunit of the ATP-sensitive potassium channel (K(ATP)), are the commonest cause of permanent neonatal diabetes (PNDM). In addition to diabetes, some KCNJ11 mutations also result in marked developmental delay and epilepsy. These mutations are more severe on functional characterization. We investigated whether mutations in KCNJ11 could also give rise to TNDM. We identified the three novel heterozygous mutations (G53S, G53R, I182V) in three of 11 probands with clinically defined TNDM, who did not have chromosome 6q24 abnormalities. The mutations co-segregated with diabetes within families and were not found in 100 controls. All probands had insulin-treated diabetes diagnosed in the first 4 months and went into remission by 7-14 months. Functional characterization of the TNDM associated mutations was performed by expressing the mutated Kir6.2 with SUR1 in Xenopus laevis oocytes. All three heterozygous mutations resulted in a reduction in the sensitivity to ATP when compared with wild-type (IC(50) approximately 30 versus approximately 7 microM, P-value for is all <0.01); however, this was less profoundly reduced than with the PNDM associated mutations. In conclusion, mutations in KCNJ11 are the first genetic cause for remitting as well as permanent diabetes. This suggests that a fixed ion channel abnormality can result in a fluctuating glycaemic phenotype. The multiple phenotypes associated with activating KCNJ11 mutations may reflect their severity in vitro.
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PMID:Relapsing diabetes can result from moderately activating mutations in KCNJ11. 1571 50


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