An Assessment of Expansion in Fragile X Syndrome Premutation Carriers Undergoing Preimplantation Genetic Diagnosis and an Exploration of Psychosocial Implications

Nori Williams, Sarah Lawrence College
Devon Olsson, Sarah Lawrence College


There is a dearth of literature describing the specific and complex genetic counseling needs of patients with known carrier status of fragile X syndrome (FXS) seeking preimplantation genetic diagnosis (PGD). This study utilized patient data to compare expansion rates in premutation carriers for FXS undergoing PGD versus expansion rates in the FXS premutation general population not undergoing PGD. A retrospective chart review was conducted using data found in medical charts from patients seen by the PGD genetic counselors at the PGD company, Reprogenetics, between 2004 to 2015. Participants were selected for carrying a premutation FXS allele and pursuing PGD. A total of 103 charts of women undergoing PGD for FXS were examined. The expansion rate of individuals in the general population of FXS carriers was higher than that in our sample population. The difference in expansion rates was significantly significant (χ= (1)= 4.12, p