A Novel Syndrome of Mandibular Hypoplasia, Deafness, and Progeroid Features Associated with Lipodystrophy, Undescended Testes, and Male Hypogonadism
ABSTRACT Mandibuloacral dysplasia (MAD) is an autosomal recessive progeroid disorder associated with type A (partial) or B (generalized) lipodystrophy and is due to mutations in lamin A/C (LMNA) or zinc metalloproteinase (ZMPSTE24) genes.
The objective of the study was to report a novel syndrome with some overlapping features with MAD.
We report seven patients with mandibular hypoplasia, deafness, progeroid features (MDP), and associated lipodystrophy. These patients have similar features to MAD patients such as hypoplastic mandible, beaked nose, stiff joints, and sclerodermatous skin. However, the patients did not harbor any disease causing variants in LMNA or ZMPSTE24 and showed distinct characteristics such as sensorineural hearing loss and absence of clavicular hypoplasia and acroosteolysis. All males with MDP had undescended testes and were hypogonadal. One adult female showed lack of breast development. Skinfold thickness, dual-energy X-ray absorptiometry and whole-body magnetic resonance imaging for body fat distribution revealed a lack of lipodystrophy in a prepubertal female but a progressive loss of sc fat presenting with partial lipodystrophy in young adults and generalized lipodystrophy in older patients.
Patients with MDP syndrome have a few overlapping but some distinct clinical features as compared with MAD, suggesting that it is a novel syndrome. The molecular basis of MDP syndrome remains to be elucidated.
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ABSTRACT: Progeria syndromes are rare disorders that involve premature aging. Mutations in BANF1 have been recently reported to cause a new hereditary progeroid syndrome that we now propose to call the Néstor-Guillermo progeria syndrome (NGPS). We describe herein the clinical features of the first two NGPS patients, who phenocopy features of classic progerias (i.e., Hutchinson-Gilford progeria syndrome or mandibuloacral dysplasia), such as aged appearance, growth retardation, decreased subcutaneous fat, thin limbs, and stiff joints. However, these NGPS patients have a distinctive phenotype. In their early adulthood (32 and 24 years of age), they have no signs of cardiovascular impairment, diabetes mellitus, or hypertriglyceridemia. In contrast, they suffer profound skeletal abnormalities that affect their quality of life. The observed differences are of utmost importance to patients and their families and palliation of osseous manifestations is a priority, given their relatively long lifespan. We define NGPS as a chronic progeria because of its slow clinical course and relatively long survival, despite its early onset. Understanding the differences between progeria syndromes might contribute to the development of treatment strategies for common skeletal conditions, as well as aging itself.American Journal of Medical Genetics Part A 11/2011; 155A(11):2617-25. DOI:10.1002/ajmg.a.34249 · 2.05 Impact Factor
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ABSTRACT: CONTEXT: Lipodystrophies are heterogeneous, genetic or acquired disorders characterized by selective loss of body fat and predisposition to insulin resistance. The extent of fat loss determines the severity of associated metabolic complications such as diabetes mellitus, hypertriglyceridemia, and hepatic steatosis. EVIDENCE ACQUISITION AND SYNTHESIS: Both original and review articles were found via PubMed search reporting on clinical features and management of various types of lipodystrophies and were integrated with the author's knowledge of the field. CONCLUSION: The autosomal recessive congenital generalized lipodystrophy and autosomal dominant familial partial lipodystrophy (FPL) are the two most common types of genetic lipodystrophies. Mutations in AGPAT2, BSCL2, CAV1, and PTRF have been reported in congenital generalized lipodystrophy and in LMNA, PPARG, AKT2, and PLIN1 in FPL. CIDEC is the disease gene for autosomal recessive, FPL and LMNA and ZMPSTE24 for autosomal recessive, mandibuloacral dysplasia-associated lipodystrophy. Recently, an autosomal recessive autoinflammatory lipodystrophy syndrome was reported to be due to PSMB8 mutation. Molecular genetic bases of many rare forms of genetic lipodystrophies remain to be elucidated. The most prevalent subtype of acquired lipodystrophy currently occurs with prolonged duration of protease inhibitor-containing, highly-active antiretroviral therapy in HIV-infected patients. The acquired generalized and partial lipodystrophies are mainly autoimmune in origin and display complement abnormalities. Localized lipodystrophies occur due to drug or vaccine injections, pressure, panniculitis, and other unknown reasons. The current management includes cosmetic surgery and early identification and treatment of metabolic and other complications with diet, exercise, hypoglycemic drugs, and lipid-lowering agents.The Journal of Clinical Endocrinology and Metabolism 08/2011; 96(11):3313-25. DOI:10.1210/jc.2011-1159 · 6.31 Impact Factor
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ABSTRACT: DNA polymerase δ, whose catalytic subunit is encoded by POLD1, is responsible for lagging-strand DNA synthesis during DNA replication. It carries out this synthesis with high fidelity owing to its intrinsic 3'- to 5'-exonuclease activity, which confers proofreading ability. Missense mutations affecting the exonuclease domain of POLD1 have recently been shown to predispose to colorectal and endometrial cancers. Here we report a recurring heterozygous single-codon deletion in POLD1 affecting the polymerase active site that abolishes DNA polymerase activity but only mildly impairs 3'- to 5'-exonuclease activity. This mutation causes a distinct multisystem disorder that includes subcutaneous lipodystrophy, deafness, mandibular hypoplasia and hypogonadism in males. This discovery suggests that perturbing the function of the ubiquitously expressed POLD1 polymerase has unexpectedly tissue-specific effects in humans and argues for an important role for POLD1 function in adipose tissue homeostasis.Nature Genetics 06/2013; DOI:10.1038/ng.2670 · 29.65 Impact Factor