EMQN best practice guidelines for the molecular genetic testing and reporting of fragile X syndrome and other fragile X-associated disorders.

ABSTRACT: Different mutations occurring in the unstable CGG repeat in 5' untranslated region of FMR1 gene are responsible for three fragile X-associated disorders. An expansion of over ∼200 CGG repeats when associated with abnormal methylation and inactivation of the promoter is the mutation termed 'full mutation' and is responsible for fragile X syndrome (FXS), a neurodevelopmental disorder described as the most common cause of inherited intellectual impairment. The term 'abnormal methylation' is used here to distinguish the DNA methylation induced by the expanded repeat from the 'normal methylation' occurring on the inactive X chromosomes in females with normal, premutation, and full mutation alleles. All male and roughly half of the female full mutation carriers have FXS. Another anomaly termed '

SUBMITTER: Biancalana V 

PROVIDER: S-EPMC4666582 | biostudies-literature | 2015 Apr

REPOSITORIES: biostudies-literature