Fragile X Syndrome [FMR1]: X-linked condition-features include mental retardation, behavioral problems (autistic-like features, etc), and characteristic facial features in affected males. Affected females may also have milder clinical manifestations. Premutation carrier females are at increased risk for premature ovarian insufficiency; whereas premutation carrier males are at increased risk for Fragile X-associated tremor/ataxia syndrome.
Ashkenazi Jewish Carrier Frequency: 1 in 115
Sephardic-Mizrahi Jewish Carrier Frequency: 1 in 250