Neuroanatomical Profile of Young Females with Fragile X Syndrome: A Voxel-Based Morphometry Analysis

• Published in: Cerebral cortex (New York, N.Y. 1991) Vol. 32; no. 11; pp. 2310 - 2320
• Main Authors: Lee, Cindy H, Bartholomay, Kristi L, Marzelli, Matthew J, Miller, Jonas G, Bruno, Jennifer L, Lightbody, Amy A, Reiss, Allan L
• Format: Journal Article
• Language: English
• Published: United States Oxford University Press 31.05.2022
• Subjects: Original; VBM; voxel-based morphometry; brain MRI; brain volume; fragile X syndrome
• ISSN: 1047-3211; 1460-2199
• DOI: 10.1093/cercor/bhab319

Abstract Fragile X syndrome is a genetic condition associated with alterations in brain and subsequent cognitive development. However, due to a milder phenotype relative to males, females with fragile X syndrome are underrepresented in research studies. In the current study, we investigate neuroanatomical differences in young females (age range: 6.03–16.32 years) with fragile X syndrome (N = 46) as compared to age-, sex-, and verbal abilities-matched participants (comparison group; N = 35). Between-group analyses of whole-brain and regional brain volumes were assessed using voxel-based morphometry. Results demonstrate significantly larger total gray and white matter volumes in girls with fragile X syndrome compared to a matched comparison group (Ps < 0.001). In addition, the fragile X group showed significantly larger gray matter volume in a bilateral parieto-occipital cluster and a right parieto-occipital cluster (Ps < 0.001). Conversely, the fragile X group showed significantly smaller gray matter volume in the bilateral gyrus rectus (P < 0.03). Associations between these regional brain volumes and key socio-emotional variables provide insight into gene–brain–behavior relationships underlying the fragile X syndrome phenotype in females. These findings represent the first characterization of a neuroanatomical phenotype in a large sample of girls with fragile X syndrome and expand our knowledge about potential neurodevelopmental mechanisms underlying cognitive–behavioral outcomes in this condition.