ABSTRACT Objective: Our aim is to establish genetic diagnosis of congenital generalized lipodystrophy (CGL) using targeted massively parallel sequencing (MPS), also known as next-generation sequencing (NGS). Subjects and methods: Nine unrelated individuals with a clinical diagnosis of CGL were recruited. We used a customized panel to capture genes related to genetic lipodystrophies. DNA libraries were generated, sequenced using the Illumina MiSeq, and bioinformatics analysis was performed. Results: An accurate genetic diagnosis was stated for all nine patients. Four had pathogenic variants in AGPAT2 and three in BSCL2. Three large homozygous deletions in AGPAT2 were identified by copy-number variant analysis. Conclusions: Although we have found allelic variants in only 2 genes related to CGL, the panel was able to identify different variants including deletions that would have been missed by Sanger sequencing. We believe that MPS is a valuable tool for the genetic diagnosis of multi-genes related diseases, including CGL.

O diabetes do tipo MODY (maturity-onset diabetes of the young) caracteriza-se por herança autossômica dominante, início precoce da hiperglicemia e defeitos na secreção de insulina. Os subtipos de MODY apresentam diferenças genéticas, metabólicas e clínicas. O MODY 2 é caracterizado por hiperglicemia leve assintomática e raramente requer tratamento farmacológico. O diagnóstico preciso de MODY é importante para se determinar o tratamento e o prognóstico. Relatamos duas mutações no gene GCK em heterozigose identificadas durante investigação de baixa estatura. Caso 1: paciente do sexo masculino, com 14 anos, pré-púbere, avaliado por atraso constitucional do crescimento e da puberdade. Durante o acompanhamento, apresentou glicemia de jejum alterada (113 mg/dL), aumento de HbA1c (6,6%) e anticorpos anticélulas β negativos. Seu pai e dois irmãos também apresentavam glicemia levemente elevada. A mãe tinha glicemia normal. Foi identificada no gene GCK uma mutação missense em heterozigose, p.Arg191Trp. Dezoito membros da família foram rastreados e 11 apresentavam essa mutação. Caso 2: paciente do sexo masculino, com 4 anos, em avaliação por baixa estatura. Não apresentou alterações laboratoriais, exceto por glicemia elevada (118 mg/dL). Anticorpos anticélulas β foram negativos. Seu pai, uma tia paterna e a avó paterna também apresentavam glicemia discretamente elevada, e a mãe, glicemia normal. A mutação missense em heterozigose, p.Glu221Lys, foi identificada no paciente-índice e em 4 membros da família. Todos os pacientes afetados apresentavam hiperglicemia leve. Essas mutações não foram identificadas nos indivíduos com glicemia normal. O rastreamento de mutações no gene GCK deve ser considerado em pacientes com hiperglicemia crônica leve e de início precoce, história familiar de glicemia elevada e anticorpos anticélulas β negativos. Arq Bras Endocrinol Metab. 2012;56(8):519-24

Maturity-onset diabetes of the young (MODY) is characterized by an autosomal dominant mode of inheritance, early onset of hyperglycemia, and defects of insulin secretion. MODY subtypes described present genetic, metabolic, and clinical differences. MODY 2 is characterized by mild asymptomatic fasting hyperglycemia, and rarely requires pharmacological treatment. Hence, precise diagnosis of MODY is important for determining management and prognosis. We report two heterozygous GCK mutations identified during the investigation of short stature. Case 1: a prepubertal 14-year-old boy was evaluated for constitutional delay of growth and puberty. During follow-up, he showed abnormal fasting glucose (113 mg/dL), increased level of HbA1c (6.6%), and negative β-cell antibodies. His father and two siblings also had slightly elevated blood glucose levels. The mother had normal glycemia. A GCK heterozygous missense mutation, p.Arg191Trp, was identified in the proband. Eighteen family members were screened for this mutation, and 11 had the mutation in heterozygous state. Case 2: a 4-year-old boy investigated for short stature revealed no other laboratorial alterations than elevated glycemia (118 mg/dL); β-cell antibodies were negative. His father, a paternal aunt, and the paternal grandmother also had slightly elevated glycemia, whereas his mother had normal glycemia. A GCK heterozygous missense mutation, p.Glu221Lys, was identified in the index patient and in four family members. All affected patients had mild elevated glycemia. Individuals with normal glycemia did not harbor mutations. GCK mutation screening should be considered in patients with chronic mild early-onset hyperglycemia, family history of impaired glycemia, and negative β-cell antibodies. Arq Bras Endocrinol Metab. 2012;56(8):519-24

Neoplasias encefálicas constituem a segunda causa neurológica de morte. Foi desenvolvido um modelo animal simplificado de tumor cerebral em ratos utilizando a linhagem celular W256 (carcinoma 256 de Walker) para permitir teste de novos tratamentos. Ratos Wistar foram inoculados nos gânglios da base (caudato subfrontal direito) com uma solução celular tumoral, por via estereotáxica. Este modelo demonstrou crescimento tumoral em 95% dos animais inoculados com sucesso, além de mostrar ausência de metástases extracranianas e infecção sistêmica. A mediana de sobrevida dos animais foi de 10 dias. O volume tumoral estimado foi de 17,08±6,7 mm³ no sétimo dia e de 67,25±19,8 mm³ no nono dia após a inoculação. O tempo de duplicação foi estimado em 24,25 h. O crescimento tumoral induziu a caquexia, mas não houve alterações bioquímicas ou hematológicas. Esse modelo permite fácil reprodução e comporta-se como um tumor indiferenciado, mostrando potencial para estudar migração celular tumoral no sistema nervoso central. Dexametasona 3,0 mg/kg/dia reduziu significantemente a sobrevida dos animais inoculados com tumor nesse modelo. Ciclosporina 10 mg/kg/dia não teve efeito na sobrevida, sendo sua administração bem tolerada.

Brain cancer is the second neurological cause of death. A simplified animal brain tumor model using W256 (carcinoma 256, Walker) cell line was developed to permit the testing of novel treatment modalities. Wistar rats had a cell tumor solution inoculated stereotactically in the basal ganglia (right subfrontal caudate). This model yielded tumor growth in 95% of the animals, and showed absence of extracranial metastasis and systemic infection. Survival median was 10 days. Estimated tumor volume was 17.08±6.7 mm³ on the 7th day and 67.25±19.8 mm³ on 9th day post-inoculation. Doubling time was 24.25 h. Tumor growth induced cachexia, but no hematological or biochemical alterations. This model behaved as an undifferentiated tumor and can be promising for studying tumor cell migration in the central nervous system. Dexamethasone 3.0 mg/kg/day diminished significantly survival in this model. Cyclosporine 10 mg/kg/day administration was safely tolerated.