RESUMO
PURPOSE: We studied a two-generation family with an inherited syndrome of prominent corneal nerves and lesions of the tongue resembling neuromas without the characteristic neoplasms of the multiple endocrine neoplasia type 2B syndrome. Several different point mutations in the RET proto-oncogene on chromosome 10 have been associated with the multiple endocrine neoplasia type 2 syndromes. Molecular genetic studies of families with partial phenotypic expression of these syndromes may aid in further understanding the origin of the variety of clinical manifestations observed in multiple endocrine neoplasia type 2. METHODS: A family consisting of an 8-year-old male proband, his 10-year-old sister, and 40-year-old mother was identified as having prominent corneal nerves and lesions of the tongue resembling neuromas. Pentagastrin-stimulated serum calcitonin levels were measured in the mother and sister. Molecular genetic studies were performed on all three affected members, to look for the specific point mutation seen in over 95% of patients with multiple endocrine neoplasia type 2B. RESULTS: Serum calcitonin levels were normal, indicating no C-cell hyperplasia or medullary thyroid carcinoma. Molecular genetic studies on these individuals did not disclose the specific point mutation seen in multiple endocrine neoplasia type 2B. CONCLUSIONS: This family demonstrates some of the phenotypic features of the multiple endocrine neoplasia type 2B syndrome without the characteristic neoplasms or the mutation in the RET proto-oncogene associated with multiple endocrine neoplasia type 2B. Their physical findings may be caused by genetic alterations within the RET proto-oncogene on chromosome 10 at yet undetermined sites.
Assuntos
Córnea/inervação , Doenças da Córnea/genética , Proteínas de Drosophila , Neoplasia Endócrina Múltipla Tipo 2b/genética , Neuroma/genética , Neoplasias da Língua/genética , Adulto , Sequência de Bases , Calcitonina/sangue , Criança , Cromossomos Humanos Par 10 , Córnea/patologia , Doenças da Córnea/sangue , Doenças da Córnea/patologia , DNA/análise , Primers do DNA/química , Feminino , Humanos , Masculino , Dados de Sequência Molecular , Neoplasia Endócrina Múltipla Tipo 2b/sangue , Neoplasia Endócrina Múltipla Tipo 2b/patologia , Neuroma/sangue , Neuroma/patologia , Fenótipo , Mutação Puntual/genética , Reação em Cadeia da Polimerase , Proto-Oncogene Mas , Proteínas Proto-Oncogênicas/genética , Proteínas Proto-Oncogênicas c-ret , Proto-Oncogenes , Receptores Proteína Tirosina Quinases/genética , Neoplasias da Língua/sangue , Neoplasias da Língua/patologiaAssuntos
Síndrome da Retração Ocular/complicações , Oftalmoplegia/complicações , Ambliopia/complicações , Pré-Escolar , Síndrome da Retração Ocular/congênito , Síndrome da Retração Ocular/etiologia , Esotropia/complicações , Feminino , Lateralidade Funcional , Cabeça/anormalidades , Humanos , Masculino , Pescoço/anormalidades , Fenômenos Fisiológicos Oculares , Gravidez , Efeitos Tardios da Exposição Pré-Natal , Estrabismo/complicaçõesRESUMO
An advanced case of rhabdomyosarcoma of the upper eyelid is used to demonstrate and discuss the principles of diagnosis and proper management of this most malignant extra-ocular neoplasm in the orbital region.
