Fragile X Syndrome Caused by Maternal Somatic Mosaicism of FMR1 Gene: Case Report and Literature Review.

ABSTRACT: Fragile X syndrome (FXS) is caused by an abnormal expansion of the number of trinucleotide CGG repeats located in the 5' UTR in the first exon of the FMR1 gene. Size and methylation mosaicisms are commonly observed in FXS patients. Both types of mosaicisms might be associated with less severe phenotypes depending on the number of cells expressing FMRP. Although this dynamic mutation is the main underlying cause of FXS, other mechanisms, including point mutations or deletions, can lead to FXS. Several reports have demonstrated that de novo deletions including the entire or a portion of the FMR1 gene end up with the absence of FMRP and, thus, can lead to the typical clinical features of FXS. However, very little is known about the clinical manifestations associated with

SUBMITTER: Gomez-Rodriguez MJ 

PROVIDER: S-EPMC9498456 | biostudies-literature | 2022 Sep

REPOSITORIES: biostudies-literature