Expansión del triplete citosina-guanina-guanina: 3 casos de síndrome OMIM en una misma familia / Triplet expansion cytosine-guanine-guanine: Three cases of OMIM syndrome in the same family
Med. clín (Ed. impr.)
; 146(7): 311-315, abr. 2016. graf, tab
Article
in Es
| IBECS
| ID: ibc-150393
Responsible library:
ES1.1
Localization: BNCS
RESUMEN
Introducción: El aumento del número de repeticiones del triplete citosina-guanina-guanina (CGG), en el gen FMR1 es responsable de 3 síndromes OMIM con fenotipo clínico bien diferenciado: síndrome de X frágil (SXF) y 2 enfermedades en adultos portadores de la premutación (55-200 repeticiones CGG): insuficiencia ovárica primaria (FXPOI) y síndrome de temblor-ataxia (FXTAS) asociado al SXF. Observación clínica o métodos: Se estudió la mutación dinámica CGG del gen FMR1 en muestras de ADN de sangre periférica del caso índice y familiares de primer, segundo y tercer grado mediante TP-PCR, así como el porcentaje de metilación. Resultados: Se confirmó el diagnóstico del SXF en 3 pacientes (21,4%), 8 pacientes (57,1%) se encontraban en el rango de premutación, un paciente varón con mosaicismo premutación-mutación completa (7,1%) y 2 pacientes (14,3%) con estudio normal. De los 8 pacientes premutados, 3 presentaron FXPOI y un paciente varón FXTAS. Discusión: Nuestro estudio muestra la importancia de realizar un diagnóstico precoz del SXF y su consecuente estudio familiar y consejo genético, que permita identificar nuevos pacientes afectos o pacientes premutados con síndromes relacionados con el gen FMR1 (FXTAS, FXPOI) (AU)
ABSTRACT
Introduction: The dynamic increase in the number of triplet repeats of cytosine-guanine-guanine (CGG) in the FMR1gene mutation is responsible for three OMIM syndromes with a distinct clinical phenotype: Fragile X syndrome (FXS) and two pathologies in adult carriers of the premutation (55-200 CGG repeats): Primary ovarian insufficiency (FXPOI) and tremor-ataxia syndrome (FXTAS) associated with FXS. Clinical observation and methods: CGG mutation dynamics of the FMR1 gene were studied in DNA samples from peripheral blood from the index case and other relatives of first, second and third degree by TP-PCR, and the percentage methylation. Results: Diagnosis of FXS was confirmed in three patients (21.4%), eight patients (57.1%) were confirmed in the premutation range transmitters, one male patient with full mutation/permutation mosaicism (7.1%) and two patients (14.3%) with normal study. Of the eight permutated patients, three had FXPOI and one male patient had FXTAS. Discussion: Our study suggests the importance of making an early diagnosis of SXF in order to carry out a family study and genetic counselling, which allow the identification of new cases or premutated patients with FMR1 gene- associated syndromes (FXTAS, FXPOI) (AU)
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Collection:
06-national
/
ES
Database:
IBECS
Main subject:
Trinucleotide Repeat Expansion
/
Fragile X Syndrome
Type of study:
Diagnostic_studies
/
Etiology_studies
/
Prognostic_studies
/
Screening_studies
Limits:
Adolescent
/
Adult
/
Aged
/
Child
/
Child, preschool
/
Female
/
Humans
/
Male
Language:
Es
Journal:
Med. clín (Ed. impr.)
Year:
2016
Document type:
Article