Search results
Results from the WOW.Com Content Network
Fragile X syndrome (FXS) is a genetic neurodevelopmental disorder characterized by mild-to-moderate intellectual disability. [1] The average IQ in males with FXS is under 55, while about two thirds of affected females are intellectually disabled.
Fragile X-associated primary ovarian insufficiency (FXPOI) is the most common genetic cause of premature ovarian failure in women with a normal karyotype 46,XX. [1] The expansion of a CGG repeat in the 5' untranslated region of the FMR1 gene from the normal range of 5-45 repeats to the premutation range of 55-199 CGGs leads to risk of FXPOI for ovary-bearing individuals. [2]
While initially described as affecting male carriers, female carriers of the FMR1 gene mutation have also been found to develop FXTAS. However, due to X-inactivation, female carriers are much less likely to develop dementia or classic ataxia and tremor, instead demonstrating symptoms such as fibromyalgia, thyroid disease, hypertension, and ...
46,XX/46,XY chimeric or mosaic is associated with a wide spectrum of different physical presentations, with cases ranging from having a completely normal male or female phenotype [7] [8] [9] to some cases having ovotesticular syndrome. Due to this variation, genetic testing is the only way to reliably make a diagnosis.
FMR1 (Fragile X Messenger Ribonucleoprotein 1) is a human gene [5] that codes for a protein called fragile X messenger ribonucleoprotein, or FMRP. [6] This protein, most commonly found in the brain, is essential for normal cognitive development and female reproductive function.
The first trinucleotide repeat disease to be identified was fragile X syndrome, which has since been mapped to the long arm of the X chromosome. Patients carry from 230 to 4000 CGG repeats in the gene that causes fragile X syndrome, while unaffected individuals have up to 50 repeats and carriers of the disease have 60 to 230 repeats.
A research study was done in 2014 to learn if there is a relationship between macroorchidism and intellectual disability associated with decreased levels of Fragile X Mental Retardation 1 gene protein (FMRP), but in the pre-mutation or carrier state. FMRP is made from the FMR1 gene and is mainly in the brain and testis.
Sherman theorized that the gene responsible for fragile X syndrome becomes mutated through a two-step process. The first mutation, called the 'premutation', doesn't cause any clinical symptoms. A second mutation was required to convert the 'premutation' into a 'full mutation' capable of causing the clinical symptoms associated with fragile X ...