RESUMO
Molecular diagnosis is important to provide accurate genetic counseling of skeletal dysplasias (SD). Although next-generation sequencing (NGS) techniques are currently the preferred methods for analyzing these conditions, some of the published results have not shown a detection rate as high as it would be expected. The present study aimed to assess the diagnostic yield of targeted NGS combined with Sanger sequencing (SS) for low-coverage exons of genes of interest and exome sequencing (ES) in a series of patients with rare SD and use two patients as an example of our strategy. This study used two different in-house panels. Of 93 variants found in 88/114 (77%) patients, 57 are novel. The pathogenic variants found in the following genes: B3GALT6, PCYT1A, INPPL1, LIFR, of four patients were only detected by SS. In conclusion, the high diagnostic yield reached in the present study can be attributed to both a good selection of patients and the utilization of the SS for the insufficiently covered regions. Additionally, the two case reports-a patient with acrodysostosis related to PRKAR1A and another with ciliopathy associated with KIAA0753, add new and relevant clinical information to the current knowledge.
Assuntos
Disostoses , Osteocondrodisplasias , Colina-Fosfato Citidililtransferase , Galactosiltransferases , Aconselhamento Genético , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Sequenciamento do ExomaRESUMO
OBJECTIVE: Primary pigmented nodular adrenocortical disease (PPNAD) is the main endocrine manifestation of Carney complex, a multiple neoplasia syndrome caused by PRKAR1A gene mutations. The presence of PRKAR1A loss of heterozygosity (LOH) in adrenocortical tumorigenesis remains controversial. The aim of the present study is to investigate the presence of PRKAR1A LOH in adrenocortical cells in a patient with Carney complex. METHODS: The LOH was investigated using a PRKAR1A informative intragenic marker by GeneScan software analysis in DNA obtained from laser-captured microdissected cells of several adrenal nodules. Patients: A young adult male patient with Carney complex and his family were studied. RESULTS: A novel heterozygous mutation (p. Y21X) was identified at PRKAR1A in blood DNA of the male proband and his relatives. No PRKAR1A LOH was evidenced in the laser-captured microdissected cells from PPNAD tissue by different methodologies. CONCLUSION: We identified a new PRKAR1A nonsense mutation and in addition we did not evidence PRKAR1A LOH in laser-captured nodules cells, suggesting that adrenocortical tumorigenesis in PPNAD may occurs apart from the second hit.
OBJETIVO: A doença adrenocortical nodular pigmentosa primária (PPNAD) é uma das manifestações do complexo de Carney, uma neoplasia endócrina múltipla causada por mutações no PRKAR1A. A perda de heterozigose (LOH) do PRKAR1A na tumorigenese adrenal permanece controversa dada à possibilidade de contaminação com o tecido normal. Nosso objetivo foi investigar a presença de LOH no PRKAR1A a partir de células do nódulo adrenal de um paciente com complexo de Carney. MÉTODOS: A pesquisa da LOH do PRKAR1A foi realizada através do estudo de um marcador intragênico em DNA de células do nódulo adrenal microdissecadas a laser, evitando contaminação com o tecido normal. Pacientes: Um paciente com PPNAD e cinco familiares foram estudados. RESULTADOS: A nova mutação (p. Y21X) foi identificada no PRKAR1A sem evidência de LOH no tecido adrenal. CONCLUSÃO: Identificamos uma nova mutação no PRKAR1A e não evidenciamos LOH nas células dos nódulos adrenocorticais, sugerindo que a PPNAD possa ocorrer na ausência de um segundo evento molecular.
Assuntos
Adolescente , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Córtex Suprarrenal/patologia , Códon sem Sentido/genética , Subunidade RIalfa da Proteína Quinase Dependente de AMP Cíclico/genética , Perda de Heterozigosidade , Neoplasia Endócrina Múltipla/genética , Córtex Suprarrenal/citologia , Códon sem Sentido/sangue , Lasers , LinhagemRESUMO
Primary pigmented nodular adrenocortical disease (PPNAD) is a form of bilateral adrenocortical hyperplasia that is often associated with corticotrophin (ACTH)-independent Cushing's syndrome (CS) and is characterized by small to normal-sized adrenal glands containing multiple small cortical pigmented nodules (1,2). PPNAD may occur in an isolated form or associated with a multiple neoplasia syndrome, the complex of spotty skin pigmentation, myxomas, and endocrine overactivity, or Carney complex, in which Cushing's syndrome is the most common endocrine manifestation (3). Molecular studies have led to the identification of several genes, defects in which may predispose PPNAD formation; all of these molecules play important role for the cAMP signaling pathway. This review intends to present the most recent knowledge of the pathology and molecular genetics of the benign bilateral adrenocortical lesions, as well as to discuss the modern tools for diagnostics and treatment of this condition.
A doença adrenocortical nodular pigmentada primária (PPNAD) é uma forma de hiperplasia adrenocortical bilateral que está freqüentemente associada com a síndrome de Cushing (SC) ACTH-independente, sendo caracterizada por glândulas adrenais de tamanho pequeno ou normal contendo múltiplos nódulos corticais pigmentados pequenos. PPNAD pode ocorrer de forma isolada ou associada com uma síndrome de neoplasia múltipla, o complexo de manchas pigmentadas na pele (lentigíneas), mixomas e hiperatividade endócrina, ou complexo de Carney, no qual a SC é a manifestação endócrina mais comum. Estudos moleculares levaram à identificação de vários genes que, quando mutados, podem predispor à formação da PPNAD; todas essas moléculas têm um papel importante na via de sinalização do AMPc. Esta revisão pretende apresentar os conhecimentos mais recentes sobre a patologia e a genética molecular das lesões adrenocorticais benignas bilaterais e discutir os modernos instrumentos para diagnóstico e tratamento dessa condição.