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Abstract
PURPOSE OF REVIEW Genetic or acquired lipodystrophies are characterized by selective loss of body fat along with predisposition towards metabolic complications of insulin resistance, such as diabetes mellitus, hypertriglyceridemia, hepatic steatosis, polycystic ovarian syndrome, and acanthosis nigricans. In this review, we discuss the various subtypes and when to suspect and how to diagnose lipodystrophy. RECENT FINDINGS The four major subtypes are autosomal recessive, congenital generalized lipodystrophy (CGL); acquired generalized lipodystrophy (AGL), mostly an autoimmune disorder; autosomal dominant or recessive familial partial lipodystrophy (FPLD); and acquired partial lipodystrophy (APL), an autoimmune disorder. Diagnosis of lipodystrophy is mainly based upon physical examination findings of loss of body fat and can be supported by body composition analysis by skinfold measurements, dual-energy x-ray absorptiometry, and whole-body magnetic resonance imaging. Confirmatory genetic testing is helpful in the proband and at-risk family members with suspected genetic lipodystrophies. The treatment is directed towards the specific comorbidities and metabolic complications, and there is no treatment to reverse body fat loss. Metreleptin should be considered as the first-line therapy for metabolic complications in patients with generalized lipodystrophy and for prevention of comorbidities in children. Metformin and insulin therapy are the best options for treating hyperglycemia and fibrates and/or fish oil for hypertriglyceridemia. Lipodystrophy should be suspected in lean and muscular subjects presenting with diabetes mellitus, hypertriglyceridemia, non-alcoholic fatty liver disease, polycystic ovarian syndrome, or amenorrhea. Diabetologists should be aware of lipodystrophies and consider genetic varieties as an important subtype of monogenic diabetes.
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Affiliation(s)
- Nivedita Patni
- Division of Pediatric Endocrinology, Department of Pediatrics, UT Southwestern Medical Center, Dallas, TX, USA
| | - Abhimanyu Garg
- Division of Nutrition and Metabolic Diseases, Department of Internal Medicine and the Center for Human Nutrition, UT Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX, 75390-8537, USA.
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Montenegro Junior RM, Lima GEDCP, Fernandes VO, Montenegro APDR, Ponte CMM, Martins LV, Pinheiro DP, de Moraes MEA, de Moraes Filho MO, d’Alva CB. Leu124Serfs*26, a novel AGPAT2 mutation in congenital generalized lipodystrophy with early cardiovascular complications. Diabetol Metab Syndr 2020; 12:28. [PMID: 32280377 PMCID: PMC7137278 DOI: 10.1186/s13098-020-00538-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/05/2019] [Accepted: 04/01/2020] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND Congenital generalized lipodystrophy (CGL) is a rare autosomal recessive disorder characterized by the near-total loss of subcutaneous adipose tissue soon after birth, resulting in ectopic fat deposition and severe metabolic disturbances. Most cases are caused by AGPAT2 or BSCL2 gene mutations. We aimed to report two unrelated CGL patients with a novel frameshift mutation in AGPAT2 (p.Leu124Serfs*26). METHODS Clinical features and laboratory were obtained by medical interview and medical records review. DNA was extracted, amplified and sequenced. Mutation Taster was used to estimate the potential biological impact of the AGPAT2 mutations on the protein function. RESULTS Patient 1: a 30-year-old woman with lipodystrophy phenotype at birth and diagnosis of diabetes at age 13 presented with severe hypertriglyceridemia and pancreatitis at age 17, hypertension and albuminuria at age 18, proliferative diabetic retinopathy with visual loss at age 25, and an acute myocardial infarction due to multivessel coronary disease during a hospitalization for forefoot amputation at age 29. At this time, she required hemodialysis due to end-stage renal disease. Patient 2: a 12-year-old girl with lipodystrophy phenotype and hypertriglyceridemia detected in the first year of life and abnormalities in the global longitudinal strain, evaluated by speckle-tracking echocardiography last year. Molecular analysis identified a c.369_372delGCTC (p.Leu124Serfs*26) AGPAT2 mutation in both unrelated patients, a compound heterozygous mutation in Patient 1, and homozygous mutation in Patient 2. CONCLUSION We describe two unrelated patients with type 1 CGL due to Leu124Serfs*26, a novel AGPAT2 frameshift mutation, presenting as early cardiovascular disease. These findings suggest an association between Leu124Serfs*26 and a more aggressive phenotype.
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Affiliation(s)
- Renan Magalhães Montenegro Junior
- Brazilian Group for the Study of Inherited and Acquired Lipodystrophies (BRAZLIPO), Faculdade de Medicina, Universidade Federal do Ceará, Rua Professor Costa Mendes, 1608, Rodolfo Teófilo, Fortaleza, Ceará 60416200 Brazil
| | - Grayce Ellen da Cruz Paiva Lima
- Brazilian Group for the Study of Inherited and Acquired Lipodystrophies (BRAZLIPO), Faculdade de Medicina, Universidade Federal do Ceará, Rua Professor Costa Mendes, 1608, Rodolfo Teófilo, Fortaleza, Ceará 60416200 Brazil
| | - Virgínia Oliveira Fernandes
- Brazilian Group for the Study of Inherited and Acquired Lipodystrophies (BRAZLIPO), Faculdade de Medicina, Universidade Federal do Ceará, Rua Professor Costa Mendes, 1608, Rodolfo Teófilo, Fortaleza, Ceará 60416200 Brazil
| | - Ana Paula Dias Rangel Montenegro
- Brazilian Group for the Study of Inherited and Acquired Lipodystrophies (BRAZLIPO), Faculdade de Medicina, Universidade Federal do Ceará, Rua Professor Costa Mendes, 1608, Rodolfo Teófilo, Fortaleza, Ceará 60416200 Brazil
| | - Clarisse Mourão Melo Ponte
- Brazilian Group for the Study of Inherited and Acquired Lipodystrophies (BRAZLIPO), Faculdade de Medicina, Universidade Federal do Ceará, Rua Professor Costa Mendes, 1608, Rodolfo Teófilo, Fortaleza, Ceará 60416200 Brazil
| | - Lívia Vasconcelos Martins
- Brazilian Group for the Study of Inherited and Acquired Lipodystrophies (BRAZLIPO), Faculdade de Medicina, Universidade Federal do Ceará, Rua Professor Costa Mendes, 1608, Rodolfo Teófilo, Fortaleza, Ceará 60416200 Brazil
| | | | | | | | - Catarina Brasil d’Alva
- Brazilian Group for the Study of Inherited and Acquired Lipodystrophies (BRAZLIPO), Faculdade de Medicina, Universidade Federal do Ceará, Rua Professor Costa Mendes, 1608, Rodolfo Teófilo, Fortaleza, Ceará 60416200 Brazil
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Abstract
Congenital generalized lipodystrophy (CGL) is a heterogeneous autosomal recessive disorder characterized by a near complete lack of adipose tissue from birth and, later in life, the development of metabolic complications, such as diabetes mellitus, hypertriglyceridaemia and hepatic steatosis. Four distinct subtypes of CGL exist: type 1 is associated with AGPAT2 mutations; type 2 is associated with BSCL2 mutations; type 3 is associated with CAV1 mutations; and type 4 is associated with PTRF mutations. The products of these genes have crucial roles in phospholipid and triglyceride synthesis, as well as in the formation of lipid droplets and caveolae within adipocytes. The predominant cause of metabolic complications in CGL is excess triglyceride accumulation in the liver and skeletal muscle owing to the inability to store triglycerides in adipose tissue. Profound hypoleptinaemia further exacerbates metabolic derangements by inducing a voracious appetite. Patients require psychological support, a low-fat diet, increased physical activity and cosmetic surgery. Aside from conventional therapy for hyperlipidaemia and diabetes mellitus, metreleptin replacement therapy can dramatically improve metabolic complications in patients with CGL. In this Review, we discuss the molecular genetic basis of CGL, the pathogenesis of the disease's metabolic complications and therapeutic options for patients with CGL.
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Affiliation(s)
- Nivedita Patni
- Division of Paediatric Endocrinology, Department of Paediatrics, Department of Internal Medicine, Centre for Human Nutrition, UT Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX 75390-8537, USA
| | - Abhimanyu Garg
- Division of Nutrition and Metabolic Diseases, Department of Internal Medicine, Center for Human Nutrition, UT Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX 75390-8537, USA
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