Pesquisa molecular y clínica del síndrome de X-frágil en 300 pacientes con retardo mental inespecífico / Clinical and metabolic screening for fragile X syndrome in 300 patients with unspecific mental retardation
Rev. méd. Chile
;
126(8): 911-8, ago. 1998. ilus, tab
Artículo
en Español
| LILACS
| ID: lil-232936
ABSTRACT
Background:
Fragile X syndrome is the most freqent cause of mental retardation linked to the X chromosome. In the majority of cases, the mutation responsible for the syndrome is an expansion of the trinucleotide repeat (CGG)n, present in the 5' region of exon 1 of the gene for mental retardation associated with fragile X syndrome (FMR-1).Aim:
To report the results of a fragile X screening in patients with mental retardation. Patients andmethods:
Fragile X screening using polymerase chain reaction methods was done in 386 X chromosomes from 300 patients (214 male), aged 4 to 26 years old. The modified Hagerman test was applied to male patients. Hybridization techniques were applied in a subgroup of 51 patients.Results:
(CGG)n 30 was the allele found with the highest frequency in 50.2percent of patients. (CGG)n 29 was found in 29percent of patients. One subject had an allele with 46 CGG repeats, which corresponds to the gray zone. Hybridization studies were highly concordant with PCR, detecting four males with fragile X syndrome and a carrier female. The average clinical score of mental retardation not due to fragile X syndrome was 10.3 ñ 3.4 (range 3 to 23), and 97percent of males had a score below 19. The concordance between scores over 20 and molecular genotype was 98percent.Conclusions:
The distribution of (CGG)n repeats, observed in this study, was significantly different to that previously reported for a normal Chilean population. The dispersion of molecular status and clinical score was lower than previously described using cytogenetic techniques
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Índice:
LILACS (Américas)
Asunto principal:
Síndrome del Cromosoma X Frágil
/
Discapacidad Intelectual
Tipo de estudio:
Estudio diagnóstico
/
Estudio de tamizaje
Límite:
Adolescente
/
Adulto
/
Child, preschool
/
Femenino
/
Humanos
/
Masculino
Idioma:
Español
Revista:
Rev. méd. Chile
Asunto de la revista:
Medicina
Año:
1998
Tipo del documento:
Artículo
/
Documento de proyecto
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