FMR1 premutation was reported to be responsible for up to 3.3%-6.7% of sporadic POF and 13% of familial cases in Caucasians, while the data was absent in Chinese population.
To estimate the frequency of FMR1 premutations among Portuguese males with non-familial, late-onset movement disorders of unknown etiology, we assessed CGG repeat size in males with disease onset after the age of 50 and negative or unknown family history for late-onset movement disorders, who were sent for SCA, HD, or PD genetic testing at a reference laboratory.
This case-control study was conducted to enumerate CGG repeats in the FMR1 gene in 80 Indian women with non-familial, non-syndromic POF, and 70 controls from the same ethnicity.
The coexistence within the same family of two dysfunctional ovarian conditions, one FMR1-related and one not FMR1-related, suggests that the complexity of familial POF conditions is larger than expected.