Mutación c.3037G>A en el gen FBN1 asociado a síndrome de Marfan variante neonatal / Mutation c.3037G>A in the FBN1 gene associated with neonatal Marfan syndrome variant

Resumen: El síndrome de Marfan ([SM], OMIM 154700) es un trastorno del tejido conectivo que exhibe un patrón de herencia autosómico dominante, cuyas características clínicas pueden afectar de forma variable múltiples sistemas u órganos. Es causado por mutaciones en el gen FBN1 (OMIM 134797) localizado en 15q21.1. El SM neonatal es una variedad infrecuente de la entidad asociado con mutaciones en el cambio de sentido entre los exones 23-33 y mutaciones truncadas, exhibe un fenotipo más severo y alto porcentaje de mortalidad en los primeros años de vida. Se presenta el caso de adolescente masculino con SM neonatal y mutaciones en el cambio de sentido (c.3037G>A; p.Gly225Arg) en el exón 24 del gen FBN1. Ante estos hallazgos se estudió la variación fenotípica interfamiliar, la evaluación médica interdisciplinaria precoz necesaria para el manejo de las posibles complicaciones, así como el oportuno asesoramiento genético familiar.

Abstract: Marfan syndrome ([MS], OMIM 154700) is a connective tissue disorder that exhibits an autosomal dominant pattern of inheritance, whose clinical characteristics can affect multiple systems or organs in a variable way. It is caused by mutations in the FBN1 gene (OMIM 134797) located at 15q21.1. Neonatal MS is an uncommon variety of the entity associated with missense mutation between exons 23-33 and truncating mutations, exhibits a more severe phenotype and high percentage of mortality in the first years of life. The case of male adolescent with neonatal MS and missense mutation (c.3037G> A; p.Gly225Arg) in exon 24 of the FBN1 gene is presented. Given these findings, interfamilial phenotype variation, the early interdisciplinary medical evaluation necessary for the management of possible complications, as well as the appropriate family genetic counseling were studied.

[Mutation c.3037G>A in the FBN1 gene associated with neonatal Marfan syndrome variant]. / Mutación c.3037G>A en el gen FBN1 asociado a síndrome de Marfan variante neonatal.

Marfan syndrome ([MS], OMIM 154700) is a connective tissue disorder that exhibits an autosomal dominant pattern of inheritance, whose clinical characteristics can affect multiple systems or organs in a variable way. It is caused by mutations in the FBN1 gene (OMIM 134797) located at 15q21.1. Neonatal MS is an uncommon variety of the entity associated with missense mutation between exons 23-33 and truncating mutations, exhibits a more severe phenotype and high percentage of mortality in the first years of life. The case of male adolescent with neonatal MS and missense mutation (c.3037G> A; p.Gly225Arg) in exon 24 of the FBN1 gene is presented. Given these findings, interfamilial phenotype variation, the early interdisciplinary medical evaluation necessary for the management of possible complications, as well as the appropriate family genetic counseling were studied.

El síndrome de Marfan ([SM], OMIM 154700) es un trastorno del tejido conectivo que exhibe un patrón de herencia autosómico dominante, cuyas características clínicas pueden afectar de forma variable múltiples sistemas u órganos. Es causado por mutaciones en el gen FBN1 (OMIM 134797) localizado en 15q21.1. El SM neonatal es una variedad infrecuente de la entidad asociado con mutaciones en el cambio de sentido entre los exones 23-33 y mutaciones truncadas, exhibe un fenotipo más severo y alto porcentaje de mortalidad en los primeros años de vida. Se presenta el caso de adolescente masculino con SM neonatal y mutaciones en el cambio de sentido (c.3037G>A; p.Gly225Arg) en el exón 24 del gen FBN1. Ante estos hallazgos se estudió la variación fenotípica interfamiliar, la evaluación médica interdisciplinaria precoz necesaria para el manejo de las posibles complicaciones, así como el oportuno asesoramiento genético familiar.

First Report on the Transmission of 'Candidatus Liberibacter americanus' from Citrus to Nicotiana tabacum cv. Xanthi.

Huanglongbing (HLB), also known as greening, is one of the most important diseases of citrus worldwide. The causal agent is a gram-negative bacterium known to inhabit the phloem of infected plants. Three different candidate species infect citrus: 'Candidatus Liberibacter africanus' found in the African continent; 'Ca. L. asiaticus' found in Asia, Brazil, and the United States; and 'Ca. L. americanus' found in Brazil. (1). Tobacco is an easily transformable plant species that can be used as an experimental host system to quickly screen for candidate genes useful to control plant pathogens. However, no evidence exists on the ability of this plant species to sustain populations of 'Ca. L. americanus'. With the purpose of transmitting 'Ca. L. americanus' from citrus to tobacco, fragments of healthy stems of Cuscuta spp. (dodder) were used to connect an HLB-infected sweet orange plant to each of 10 healthy plants of Nicotiana tabacum L. cv. Xanthi and allowed to remain connected for 30, 45, and 50 days. Three different HLB-infected orange plants and 30 tobacco plants were used in three independent experiments. Most HLB-exposed Xanthi plants exhibited chlorotic leaves after 50 days of exposure probably because of the parasitic effect of dodder; however, an average of 6, 1, and 3 Xanthi plants exhibited a unique blotchy mottle symptom after 30, 45, and 50 days of exposure, respectively. Symptomatic and asymptomatic leaves were collected and analyzed by PCR. The results consistently confirmed the presence of 'Ca. L. americanus' only in symptomatic leaves. Sequencing of the PCR product and comparison to the NCBI database also confirmed the identity of the pathogen as 'Ca. L. americanus'. Electron microscopy analysis of four symptomatic leaves indicated the presence of bacterium-like bodies with round to elongated bacilliform shapes and surrounded by two membranes. These bodies resembled those already described in HLB-infected citrus in Brazil (1). The evidence presented above confirms the successful transmission of 'Ca. L. americanus' from citrus to Xanthi using the parasitic plant Cuscuta spp. Reference: (1) F. A. O. Tanaka et al. Fitopatol. Bras. 31:99, 2006.