Absence of PRKAR1A loss of heterozygosity in laser-captured microdissected pigmented nodular adrenocortical tissue from a patient with Carney complex caused by the novel nonsense mutation p. Y21X / Ausência da perda de heterozigose do PRKAR1A em células capturadas por microdissecção a laser de tecido de nódulo pigmentoso adrenocortical de um paciente com complexo de Carney causado por uma nova mutação nonsense

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.

[Absence of PRKAR1A loss of heterozygosity in laser-captured microdissected pigmented nodular adrenocortical tissue from a patient with Carney complex caused by the novel nonsense mutation p.Y21X]. / Ausência da perda de heterozigose do PRKAR1A em células capturadas por microdissecção a laser de tecido de nódulo pigmentoso adrenocortical de um paciente com complexo de Carney causado por uma nova mutação nonsense.

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.