Targeted massively parallel sequencing for congenital generalized lipodystrophy

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.

Aggressive papillary thyroid carcinoma in a child with type 2 congenital generalized lipodystrophy

SUMMARY Thyroid carcinoma (TC) is rare in children, particularly in those aged < 10 years. Several studies have demonstrated a correlation between neoplasms and hyperinsulinemia and insulin resistance, which are often associated with a higher risk for and/or aggressiveness of the neoplasm. Congenital generalized lipodystrophy (CGL) with autosomal recessive inheritance is a rare disease and is characterized by the lack of adipose tissue, severe insulin resistance, and early metabolic disturbances. Here, we reported a rare case of a type 2 CGL in a girl who presented with a papillary TC (PTC) at the age of 7 years. She had no family history of TC or previous exposure to ionizing radiation. She had a generalized lack of subcutaneous fat, including the palmar and plantar regions, muscle hypertrophy, intense acanthosis nigricans, hepatomegaly, hypertriglyceridemia, severe insulin resistance, and hypoleptinemia. A genetic analysis revealed a mutation in the BSCL2 gene (p.Thr109Asnfs* 5). Ultrasound revealed a hypoechoic solid nodule measuring 1.8 × 1.0 × 1.0 cm, and fine needle aspiration biopsy suggested malignancy. Total thyroidectomy was performed, and a histopathological examination confirmed PTC with vascular invasion and parathyroid lymph node metastasis (pT3N1Mx stage). This is the first report to describe a case of differentiated TC in a child with CGL. Severe insulin resistance that is generally observed in patients with CGL early in life, especially in those with type 2 CGL, may be associated with this uncommon presentation of aggressive PTC during childhood.

Síndrome de Berardinelli-Seip: descrição genética e metabólica de cinco pacientes / Genetic and metabolic description of five patients with Berardinelli-Seip syndrome

OBJETIVO: Descrever o perfil genético e metabólico de portadores da síndrome de Berardinelli-Seip (BSCL) acompanhados no Instituto da Criança do HC-FMUSP. SUJEITOS E MÉTODOS: Pacientes com as características clínicas da BSCL (n = 5), todas do sexo feminino, foram avaliadas com dosagens de glicose e insulina, lípides, leptina, enzimas hepáticas, análise de DNA, ultrassonografia abdominal. RESULTADOS: A deficiência de leptina e a hipertrigliceridemia foram constatadas nas cinco pacientes. Três evoluíram para diabetes melito (DM). Quatro tiveram mutação no gene AGPAT2 e uma no gene CAV1. CONCLUSÃO: As alterações metabólicas mais precoces foram a hipertrigliceridemia e a resistência insulínica, culminando no surgimento do DM à época da puberdade, sendo as mutações no gene AGPAT2 as mais frequentes em nossa casuística.

OBJECTIVE: To report the genetic and metabolic profile of patients with Berardinelli-Seip syndrome (BSCL) followed at Instituto da Criança, HC-FMUSP. SUBJECTS AND METHODS: Patients with clinical features of BSCL (n = 5), all female, were evaluated through serum levels of glucose, insulin, lipids, leptin, and liver enzymes. Abdominal sonography and DNA analysis were also performed. RESULTS: Leptin deficiency and hypertriglyceridemia were found in all the patients. Three progressed to diabetes mellitus. Four patients have mutations in AGPAT2 gene and one have a mutation in CAV1 gene. CONCLUSION: The earliest metabolic abnormalities were hypertriglyceridemia and insulin resistance, culminating in the onset of diabetes at the time of puberty. Mutations in the AGPAT2 gene were the most frequent in our patients.