These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


PUBMED FOR HANDHELDS

Search MEDLINE/PubMed


  • Title: [Clinical and molecular screening for fragile X syndrome in 300 patients with non-specific mental retardation].
    Author: Jara L, López M, Mellado C, Aspillaga M, Avendaño I, Blanco R.
    Journal: Rev Med Chil; 1998 Aug; 126(8):911-8. PubMed ID: 9830742.
    Abstract:
    BACKGROUND: Fragile X syndrome is the most frequent 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 AND METHODS: 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 50.2% of patients. (CGG)n 29 was found in 29% 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 +/- 3.4 (range 3 to 23), and 97% of males had a score below 19. The concordance between scores over 20 and molecular genotype was 98%. 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.
    [Abstract] [Full Text] [Related] [New Search]