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)

Congenital generalized lipodystrophy is an autosomal recessive disorder characterized by marked paucity of adipose tissue, extreme insulin resistance, hypertriglyceridemia, hepatic steatosis and early onset of diabetes. We report several different mutations of the gene (AGPAT2) encoding 1-acylglycerol-3-phosphate O-acyltransferase 2 in 20 affected individuals from 11 pedigrees of diverse ethnicities showing linkage to chromosome 9q34. The AGPAT2 enzyme catalyzes the acylation of lysophosphatidic acid to form phosphatidic acid, a key intermediate in the biosynthesis of triacylglycerol and glycerophospholipids. AGPAT2 mRNA is highly expressed in adipose tissue. We conclude that mutations in AGPAT2 may cause congenital generalized lipodystrophy by inhibiting triacylglycerol synthesis and storage in adipocytes.
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PMID:AGPAT2 is mutated in congenital generalized lipodystrophy linked to chromosome 9q34. 1196 37

Congenital generalized lipodystrophy (CGL) is a rare autosomal recessive disorder characterized by marked lack of body fat since birth, which results in striking muscular appearance. Patients develop extreme insulin resistance and its complications, such as diabetes, hyperlipidemia and fatty liver. Mutations in the BSCL2 (which encodes seipin, a protein of unknown function) and AGPAT2 (which encodes 1-acylglycerol-3-phosphate O-acyltransferase 2) genes have been reported in patients with CGL. AGPAT2 is a key enzyme involved in triglyceride and phospholipid biosynthesis and, thus, the discovery of AGPAT2 mutations has heightened interest in the biochemical pathways of triglyceride synthesis and their implications in human physiology and in the pathophysiology of obesity, lipodystrophies and other adipose tissue disorders. All enzymes involved in triglyceride synthesis, including AGPAT, have several known isoforms encoded by different genes. Assuming different substrate specificities of these enzymes, the human body might have many forms of triglycerides and phospholipids. Here, we discuss the significance of these in energy storage, in addition to the normal functioning of cell membranes.
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PMID:Congenital generalized lipodystrophy: significance of triglyceride biosynthetic pathways. 1282 27

Congenital generalized lipodystrophy (CGL) is a rare autosomal recessive disorder characterized by near complete absence of adipose tissue from birth. Recently, mutations in 1-acylglycerol-3-phosphate O-acyltransferase 2 (AGPAT2) and Berardinelli-Seip congenital lipodystrophy 2 (BSCL2) genes were reported in pedigrees linked to chromosomes 9q34 and 11q13, respectively. There are limited data regarding phenotypic differences between the various subtypes of CGL. Furthermore, whether there are additional loci for CGL remains unknown. Therefore, we genotyped 45 pedigrees with CGL for AGPAT2 and BSCL2 loci and compared the phenotypes in the various subtypes. Twenty-six pedigrees harbored mutations, including seven novel variants, in the AGPAT2 gene, and 11 pedigrees harbored mutations in the BSCL2 gene, including five novel variants. Eight pedigrees had no substantial alterations in either gene. Of these, three informative pedigrees showed no linkage to markers spanning the AGPAT2 and BSCL2 loci, and in six of the affected subjects, the transcripts of AGPAT2 and BSCL2 were normal. All subtypes of CGL showed high prevalence of diabetes, hypertriglyceridemia, and acanthosis nigricans. However, patients with BSCL2 mutations had lower serum leptin levels, an earlier onset of diabetes, and higher prevalence of mild mental retardation compared with other subtypes. We conclude that besides AGPAT2 and BSCL2, there may be additional loci for CGL. The genetic heterogeneity in CGL patients is accompanied by phenotypic heterogeneity.
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PMID:Phenotypic and genetic heterogeneity in congenital generalized lipodystrophy. 1455 63

Congenital generalized lipodystrophy (CGL) is a rare autosomal recessive syndrome characterized by extreme paucity of adipose tissue since birth, acanthosis nigricans, severe insulin resistance, marked hypertriglyceridemia, and early-onset diabetes mellitus. Recently, we reported mutations in the 1-acylglycerol-3-phosphate O-acyltransferase 2 (AGPAT2) gene in CGL pedigrees linked to chromosome 9q34 (CGL1 subtype), and mutations in the Seipin gene were reported in pedigrees linked to chromosome 11q13 (CGL2 subtype). Whether the two subtypes have differences in body fat distribution has not been investigated. We, therefore, compared whole-body adipose tissue distribution by magnetic resonance imaging in 10 CGL patients, of whom seven (six females, one male) had CGL1 and three (two males, one female) had CGL2. Both subtypes had marked lack of metabolically active adipose tissue located at most sc, intermuscular, bone marrow, intraabdominal, and intrathoracic regions. Paucity of mechanical adipose tissue in the palms, soles, orbits, scalp, and periarticular regions was noted in CGL2, whereas it was well preserved in CGL1 patients. We conclude that CGL patients with Seipin mutations have a more severe lack of body fat, which affects both metabolically active and mechanical adipose tissue, compared with patients with mutations in the AGPAT2 gene.
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PMID:Phenotypic heterogeneity in body fat distribution in patients with congenital generalized lipodystrophy caused by mutations in the AGPAT2 or seipin genes. 1460 85