Improved Assays for AGG Interruptions in Fragile X Premutation Carriers.

ABSTRACT: The learning disability fragile X syndrome results from the presence of >200 CGG/CCG repeats in exon 1 of the X-linked gene FMR1. Such alleles arise by expansion from maternally transmitted FMR1 premutation alleles, alleles having 55 to 200 repeats. Expansion risk is directly related to maternal repeat number. However, AGG interruptions to the repeat tract are important modifiers of expansion risk. Thus, the ability to identify such interruptions is crucial for the appropriate genetic counseling of females who are premutation carriers. First-generation triplet-primed PCR assays allow these interruptions to be detected. However, because the triplet primer used has multiple binding sites in the repeat tract, interpreting the results is not straightforward and it is not always possible to una

SUBMITTER: Hayward BE 

PROVIDER: S-EPMC5807927 | biostudies-literature | 2017 Nov

REPOSITORIES: biostudies-literature