RESUMO
Background: There is a lack of information on the clinical and molecular presentation of familial partial lipodystrophy (FPLD), a rare genetic disorder characterized by partial subcutaneous fat loss. Objective: This study aimed to provide a comprehensive assessment of the clinical, metabolic, and genetic features of FPLD in the Brazilian population. Methods: In a multicenter cross-sectional investigation we evaluated patients with FPLD across five Brazilian reference centers for lipodystrophies. Diagnosis of FPLD was made by clinical evaluation and genetic confirmation. Data on genetic, clinical, and metabolic characteristics were captured. Statistical analysis involved the utilization of the Kruskal-Wallis test to identify differences. Results: The study included 106 patients with genetic confirmation of FPLD. The mean age was 44 ± 15 years, and they were predominantly female (78.3%). LMNA pathogenic variants were identified in 85.8% of patients, PPARG in 10.4%, PLIN1 in 2.8%, and MFN2 in 0.9%. Diabetes mellitus (DM) was highly prevalent (57.5%), affecting 54 females (50.9%). Median triglycerides levels were 199 mg/dL (54-2724 mg/dL), severe hypertriglyceridemia (≥ 500 mg/dL) was found in 34.9% and pancreatitis in 8.5%. Metabolic-associated fatty liver disease (MAFLD) was observed in 56.6%, and cardiovascular disease in 10.4%. The overall mortality rate was 3.8%, due to cardiovascular events. Conclusion: This study presents an extensive cohort of Brazilian patients with FPLD, predominantly DM with several multisystem complications. A comprehensive characterization of lipodystrophy syndromes is crucial for effective patient management and care.
Assuntos
Lipodistrofia Parcial Familiar , Humanos , Feminino , Masculino , Lipodistrofia Parcial Familiar/genética , Lipodistrofia Parcial Familiar/epidemiologia , Adulto , Estudos Transversais , Pessoa de Meia-Idade , Brasil/epidemiologia , Morbidade , Lamina Tipo A/genéticaRESUMO
OBJECTIVE: To report the case of a girl presenting a severe phenotype of mandibuloacral dysplasia type A (MADA) characterized by prominent osteolytic changes and ectodermal defects, associated with a rare homozygous LMNA missense mutation (c.1579C>T). CASE DESCRIPTION: A 6-year-old girl was evaluated during hospitalization exhibiting the following dysmorphic signs: subtotal alopecia, dysmorphic facies with prominent eyes, marked micrognathia and retrognathia, small beaked nose, teeth crowding and thin lips, generalized lipodystrophy, narrow and sloping shoulders, generalized joint stiffness and bone reabsorption in the terminal phalanges. In dermatological examination, atrophic skin, loss of cutaneous elasticity, hyperkeratosis, dermal calcinosis, and hyperpigmented and hypochromic patches were observed. Radiology exams performed showed bilateral absence of the mandibular condyles, clavicle resorption with local amorphous bone mass confluence with the scapulae, shoulder joints with subluxation and severe bone dysplasia, hip dysplasia, osteopenia and subcutaneous calcifications. COMMENTS: MADA is a rare autosomal recessive disease caused by mutations in LMNA gene. It is characterized by craniofacial deformities, skeletal anomalies, skin alterations, lipodystrophy in certain regions of the body and premature ageing. Typical MADA is caused by the p.R527H mutation in the LMNA gene. However, molecular analysis performed from oral epithelial cells obtained from the patient showed the rare mutation c.1579C>T, p. R527C in the exon 9 of LMNA. This is the sixth family identified with this mutation described in the literature.
Assuntos
Lamina Tipo A , Mutação de Sentido Incorreto , Fenótipo , Humanos , Feminino , Lamina Tipo A/genética , Criança , Mandíbula/anormalidades , Mandíbula/diagnóstico por imagem , Lipodistrofia , Acro-OsteóliseRESUMO
Lipodystrophies are characterized by complete or selective loss of adipose tissue and can be acquired or inherited. Familial partial lipodystrophy (FPLD) is a hereditary lipodystrophy commonly caused by mutations in the LMNA gene. Herein, we report two cases of FPLD associated with podocytopathies. Patient 1 was diagnosed with FPLD associated with the heterozygous p.Arg482Trp variant in LMNA and had normal glucose tolerance and hyperinsulinemia. During follow-up, she developed nephroticrange proteinuria. Renal biopsy was consistent with minimal change disease. Patient 2 was diagnosed with FPLD associated with a de novo heterozygous p.Arg349Trp variant in LMNA. Microalbuminuria progressed to macroalbuminuria within 6 years and tonephrotic range proteinuria in the last year. He remained without diabetes and with hyperinsulinemia. Renal biopsy revealed focal segmental glomerulosclerosis not otherwise specified. This report provides further evidence of variable features of lipodystrophy associated with LMNA variants and the importance of long-term follow-up with evaluation of kidney dysfunction.
Assuntos
Lamina Tipo A , Lipodistrofia Parcial Familiar , Humanos , Lamina Tipo A/genética , Lipodistrofia Parcial Familiar/genética , Lipodistrofia Parcial Familiar/complicações , Feminino , Masculino , Adulto , Podócitos/patologia , MutaçãoRESUMO
The clinical phenotype of LMNA-associated dilated cardiomyopathy (DCM) varies even among individuals who share the same mutation. LMNA encodes lamin AC, which interacts with the lamin-associated protein 2 alpha (LAP2α) encoded by the TMPO gene. The LAP2α/Arg690Cys polymorphism is frequent in Latin America and was previously found to disrupt LAP2α-Lamin AC interactions in vitro. We identified a DCM patient heterozygous for both a lamin AC truncating mutation (Ser431*) and the LAP2α/Arg690Cys polymorphism. We performed protein modeling and docking experiments, and used confocal microscopy to compare leukocyte nuclear morphology among family members with different genotype combinations (wild type, LAP2α Arg690Cys heterozygous, lamin AC/Ser431* heterozygous, and LAP2α Arg690Cys/lamin AC Ser431* double heterozygous). Protein modeling predicted that 690Cys destabilizes the LAP2α homodimer and impairs lamin AC-LAP2α docking. Lamin AC-deficient nuclei (Ser431* heterozygous) showed characteristic blebs and invaginations, significantly decreased nuclear area, and increased elongation, while LAP2α/Arg690Cys heterozygous nuclei showed a lower perimeter and higher circularity than wild-type nuclei. LAP2α Arg690Cys apparently attenuated the effect of LMNA Ser431* on the nuclear area and fully compensated for its effect on nuclear circularity. Altogether, the data suggest that LAP2α/Arg690Cys may be one of the many factors contributing to phenotype variation of LMNA-associated DCM.
Assuntos
Cardiomiopatia Dilatada , Timopoietinas , Humanos , Cardiomiopatia Dilatada/genética , Cardiomiopatia Dilatada/metabolismo , Lamina Tipo A/metabolismo , Leucócitos/metabolismo , Mutação , Mutação de Sentido Incorreto , Proteínas Nucleares/genéticaRESUMO
Abstract Isolated left ventricular apical hypoplasia is a rare cardiomyopathy, with a broad range of clinical presentations. Since this entity was already described in association with osteomuscular diseases, mutation in the Lamin A/C gene has been regarded as a possible cause of this disease. This study describes the case of an asymptomatic teenager with isolated left ventricular apical hypoplasia and arthrogriposis but with no mutations in the entire Lamin A/C gene.
Assuntos
Humanos , Masculino , Adolescente , Lamina Tipo A/genética , Miocárdio Ventricular não Compactado Isolado/fisiopatologia , Artrogripose , Lamina Tipo A/deficiência , Miocárdio Ventricular não Compactado Isolado/diagnóstico , Miocárdio Ventricular não Compactado Isolado/etiologiaAssuntos
Tumores do Estroma Gastrointestinal/genética , Proteínas de Fusão Oncogênica/genética , Receptor trkA/genética , Neoplasias Retais/genética , Prolapso Retal/etiologia , Biópsia , Colonoscopia , Tumores do Estroma Gastrointestinal/diagnóstico , Tumores do Estroma Gastrointestinal/patologia , Tumores do Estroma Gastrointestinal/cirurgia , Humanos , Lamina Tipo A/genética , Masculino , Protectomia , Neoplasias Retais/diagnóstico , Neoplasias Retais/patologia , Neoplasias Retais/cirurgia , Reto/diagnóstico por imagem , Reto/patologia , Reto/cirurgia , Adulto JovemRESUMO
BACKGROUND: Dilated cardiomyopathy (DCM) is a major cause of nonischemic heart failure and death in young adults. Next generation sequencing (NGS) has become part of the diagnostic workup in idiopathic and familial DCM. More than 50 DCM genes have been identified, revealing great molecular heterogeneity and variable diagnostic yield. Interpretation of variant pathogenicity is challenging particularly in underrepresented populations, as pathogenic variant databases include studies mainly from European/Caucasian populations. To date, no studies on genomic diagnosis of DCM have been conducted in Mexico. METHODS: We recruited 55 unrelated DCM patients, 22 familial (F-DCM), and 33 idiopathic (I-DCM), and performed site-directed NGS seeking causal mutations. Diagnostic yield was defined as the proportion of individuals with at least one pathogenic (P) or likely pathogenic (LP) variant in DCM genes. RESULTS: Overall diagnostic yield was 47.3%, and higher in F-DCM (63.6%) than in I-DCM (36.4%, p = 0.047). Overall, NGS disclosed 41 variants of clinical interest (61.0% novel), 27 were classified as P/LP and 14 of unknown clinical significance. Of P/LP variants, 10 were A-band region TTN truncating variants, five were found in DSP (18.5%), five in MYH7 (18.5%), two in LMNA (7.4%), and one in RBM20, ABCC9, FKTN, ACTA1, and TNNT2. NGS findings suggested autosomal recessive inheritance in three families, two with DSP loss of function mutations in affected individuals. The increasing number of mutation reports in DCM, increasing knowledge on the functional consequences of mutations, mutational hotspots and functional domains of DCM-related proteins, the recent refinement ACMG/ClinGen Guidelines, and co-segregation analysis in DCM families helped increase the diagnostic yield. CONCLUSION: This is the first NGS study performed in a group of Mexican DCM patients, contributing to understand the mutational spectrum and complexity of DCM molecular diagnosis.
Assuntos
Cardiomiopatia Dilatada/genética , Frequência do Gene , Adolescente , Adulto , Miosinas Cardíacas/genética , Conectina/genética , Desmoplaquinas/genética , Feminino , Testes Genéticos , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Lamina Tipo A/genética , Masculino , México , Cadeias Pesadas de Miosina/genética , Análise de Sequência de DNARESUMO
The LMNA gene is associated to a huge broad of phenotypes, including congenital Emery-Dreifuss muscular dystrophy and late-onset LMNA-related muscular dystrophy. In these forms, muscle weakness, contractures, and cardiac impairment are common. In an autosomal dominant pedigree including 5 affected patients, NGS molecular analysis performed in 6 relatives identifies the heterozygous c.1129C>T p.Arg377Cys variant in the exon 6 of the LMNA gene in three of them. Clinical, laboratorial, imaging investigation of these affected patients showed a significant clinical variability: the father presented subclinical imaging muscular dystrophy masqueraded as radiculopathy. One of his sons presented cardiac arrhythmia, muscular weakness, elbow contractures, and intranuclear pseudoinclusions on muscle biopsy. A second son presented only decreased tendon reflexes. Two other brothers presenting myalgia and cramps were not carriers of the same mutation in the LMNA gene. Early diagnosis, considering these variable phenotype and genotype, is important for genetic counseling, as well as cardiac, and rehabilitation management.
Assuntos
Variação Biológica da População , Lamina Tipo A/genética , Distrofia Muscular de Emery-Dreifuss/patologia , Linhagem , Adulto , Diagnóstico Diferencial , Feminino , Testes Genéticos , Heterozigoto , Humanos , Masculino , Pessoa de Meia-Idade , Distrofia Muscular de Emery-Dreifuss/diagnóstico por imagem , Distrofia Muscular de Emery-Dreifuss/genética , Mutação de Sentido IncorretoRESUMO
BACKGROUND: Anthracyclines are highly effective anticancer medication prescribed for the treatment of breast cancer. Nevertheless, the use of anthracyclines as chemotherapeutic agents involves a risk for development of cardiac toxicity which may cause restrictive and dilated cardiomyopathy. Currently, genetic predisposition is not considered as a risk factor for cardiotoxicity associated to the use of anthracyclines. CASE PRESENTATION: We report the case of a 37-years old Panamanian female patient diagnosed with breast cancer who developed clinical signs of severe heart failure after treatment with doxorubicin. A diagnosis of anthracycline induced cardiomyopathy was made and treatment was initiated accordingly. A whole exome sequencing study performed to the patient showed the presence of a missense mutation in LMNA gene, which codifies for lamin A/C. Our results points to a correlation between the LMNA variant and the anthracycline cardiotoxicity developed by the woman. Improvement of the clinical symptoms and the left ventricle ejection fraction was observed after proper treatment. CONCLUSIONS: This case report suggests for the first time a potential genetic predisposition for anthracyclines induced cardiomyopathy in patients with mutations in LMNA gene. Perhaps chemotherapies accelerate or deliver the "second-hit" in the development of DCM in patients with genetic mutations. More data is needed to understand the contribution of LMNA variants that predispose to DCM in patients receiving cardiotoxic therapies.
Assuntos
Antibióticos Antineoplásicos/efeitos adversos , Neoplasias da Mama/tratamento farmacológico , Carcinoma Ductal de Mama/tratamento farmacológico , Cardiomiopatia Dilatada/induzido quimicamente , Cardiomiopatia Dilatada/genética , Doxorrubicina/efeitos adversos , Lamina Tipo A/genética , Mutação de Sentido Incorreto , Variantes Farmacogenômicos , Antagonistas Adrenérgicos beta/uso terapêutico , Adulto , Anti-Hipertensivos/uso terapêutico , Cardiomiopatia Dilatada/diagnóstico por imagem , Cardiomiopatia Dilatada/tratamento farmacológico , Cardiotoxicidade , Diuréticos/uso terapêutico , Feminino , Predisposição Genética para Doença , Humanos , Fatores de Risco , Resultado do TratamentoRESUMO
Familial partial lipodystrophy type 2 (FPLD2) is characterized by insulin resistance, adipose atrophy of the extremities and central obesity. Due to the resemblance with Cushing's syndrome, we hypothesized a putative role of glucocorticoid in the pathogenesis of metabolic abnormalities in FPLD2. OBJECTIVE: To evaluate the phenotypic heterogeneity and glucocorticoid sensitivity in FPLD2 patients exhibiting the p.R482W or p.R644C LMNA mutations. DESIGN, PATIENTS AND MEASUREMENTS: Prospective study with FPLD2 patients (n = 24) and controls (n = 24), who underwent anthropometric, body composition, metabolic profile and adipokines/cytokine plasma measurements. Plasma and salivary cortisol were measured in basal conditions and after 0.25, 0.5 and 1.0 mg of dexamethasone (DEX) given at 23:00 hours. Glucocorticoid receptor (GR) and 11ßHSD isoforms expression were assessed by qPCR. RESULTS: Familial partial lipodystrophy type 2 individuals presented increased waist and neck circumferences, decreased hip circumference, peripheral skinfold thickness and fat mass. Patients presented increased HOMA-IR, triglycerides, TNF-α, IL-1ß, IL-6 and IL-10, and decreased adiponectin and leptin plasma levels. FPLD2 patients showed decreased ability to suppress the HPA axis compared with controls after 0.5 mg DEX. The phenotype was more pronounced in patients harbouring the p.R482W LMNA mutation. GRß overexpression in PBMC was observed in female patients compared with female controls. CONCLUSIONS: Familial partial lipodystrophy type 2 patients exhibited anthropometric, clinical and biochemical phenotypic heterogeneity related to LMNA mutation sites and to gender. LMNA mutations affecting both lamin A and lamin C lead to more severe phenotype. FPLD2 patients also showed blunted HPA axis response to DEX, probably due to the association of increased levels of proinflammatory cytokines with GRß overexpression leading to a more severe phenotype in female.