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When does a fragile X premutation become a full mutation?
Once the size of the premutation exceeds 230 repeats, it becomes a full mutation and the FMR-1 gene is disabled. Individuals who carry the full mutation may have fragile X syndrome
What is a premutation?
the CGG sequence in the FMR-1 gene can expand to contain between 54 and 230 repeats. This stage of expansion is called a premutation. People who carry a premutation do not usually have symptoms of fragile X syndrome
How is Fragile X Syndrome Inherited?
Males and females can be carriers, male carriers can only pass on to their daughters, they will be carriers as well have a premutation. Females can pass on to their sons or daughters, they will have the premutation or the full mutation.
What risks are associated with chest x rays?
The only risk associated with chest x ray is minimal exposure to radiation, particularly for pregnant women and children.
Can you get a disease from fragile x syndromes and how?
The definition of disease is loosely defined as an illness that can potentionally be cured; Cancer is an example of a disease. . Fragile X syndrome: (FXS) is a genetic condition that causes intellectual disability, behavioral and learning challenges and various physical characteristics. Though FXS occurs in both genders, males are more frequently affected than females, and generally with greater severity. FXS is the most common known genetic ("single gene") cause of autism.Many studies have evaluated the FXS-autism link over the past decade. These studies have shown the percentage of children with FXS who have autism varying from 15 to 33 percent. This range may be due to the fact that the diagnostic criteria for autism have varied and the diagnostic tools used have changed. Since many children with FXS are interested in social interactions, they may not meet the diagnostic criteria for autism, even as they exhibit autistic-like features such as poor eye contact, shyness, social anxiety, hand-flapping and sensory issues. Autism is much more common in boys with FXS than in girls with FXS. Carriers: Approximately 1 in 250 females and 1 in 800 males carry the FMR1 premutation. They are thus "carriers" of the premutation. Premutations are defined as having 55-200 CGG repeats and can occur in both males and females. When a father passes the premutation on to his daughters, it usually does not expand to a full mutation. A man never passes the fragile X gene to his sons, since he passes only his Y chromosome to them, which does not contain a fragile X gene. A female with the FMR1 premutation will often pass on a larger version of the mutation to her children (more on this point below). She also has a 50 percent chance of passing on her normal X chromosome in each pregnancy, since usually only one of her X chromosomes has the FMR1 mutation. The chance of the premutation expanding to a full mutation is related to the size of the mother's premutation. The larger the mother's CGG repeat number, the higher the chance that it will expand to a full mutation if it is passed on. Fragile X Associated Disorders: FXTAS: is caused by a change or mutation in a gene called the FMR1 gene. All individuals with FXTAS have what is called an FMR1 premutation. Men with FXTAS inherited this genetic change from their mother, women with FXTAS can inherit it from their mother or father. FXTAS- is an "adult onset" neurodegenerative disorder, occurring more commonly in males than females. Onset is usually over 50 years of age, and most individuals had no related medical, developmental or neurological problems prior to the appearance of FXTAS symptoms. Females comprise only a small part of the FXTAS population, and their symptoms tend to be less severe. Symptoms of FXTAS include: Ataxia (balance problems). Intention tremors (during intentional movement such as pouring, writing, etc,). Memory loss (usually short-term). Mood instability, irritability, personality change, psychiatric symptoms. Parkinson's symptoms (many individuals will be misdiagnosed with Parkinson's Disease" prior to diagnosis of FXTAS). Dementia (many individuals will be misdiagnosed with Alzheimer's disease prior to diagnosis FXTAS). Cognitive decline (loss of math, reading, and verbal comprehension skills). FXTAS progresses at varying rates in different individuals. FXPOI: or fragile X-associated primary ovarian insufficiency, is one of three known Fragile X-associated Disorders (FXD). All the FXD are caused by changes in the FMR1 Gene. FXPOI is a condition in which the ovaries are not functioning at full capacity in an FMR1 premutation carrier. Common symptoms of FXPOI include absent or irregular periods, symptoms of menopause such as hot flashes, etc, early menopause and infertility. By definition, all women who have FXPOI have an FMR1 premutation. If you are experiencing FXPOI symptoms and haven't been tested you should arrange with your physician to have FMR1 genetic testing. If you have already been tested and are a confirmed FMR1 premutation carrier, you should alert your physician to the risk of FXPOI in carriers (some physicians might not be aware of this condition). All female FMR1 carriers should keep a log of their menstrual cycles and note any unusual patterns, missed cycles, abnormally long cycles (more than 35 days) or short cycles (less than 21 days). Also note any other physical changes such as hot flashes, insomnia, vaginal dryness and/or decreased libido, increased anxiety, etc. If you are concerned that you might have FXPOI, talk to your physician about having your FSH, a hormone that reflects ovarian function, measured. FSH levels increase as you approach menopause or if your ovaries are not functioning properly for your age. FXPOI occurs in about 20-25 percent of adult female FMR1 premutation carriers. It has also been reported in teenagers who are carriers, though it is less common in that population. To answer your question- Fragile X is not contagious, and you cannot get a disease from an individual diagnosed with fragile X syndrome. However- premutation carriers are at risk of developing a fragile X associated disorder.
Does fragile X get worse?
No, fragile x syndrome is not progressive
What risks are associated with D and X?
associated emotional reactions.heavy bleeding.blood clots.damage to the cervix or uterus.pelvic infection.incomplete abortion.Possible long-term risks include difficulty becoming pregnant or carrying a future pregnancy to term.
Where on the X chromosome does Fragile X take place?
Fragile X is a result of a mutation in the FMR1 gene on the X chromosome.
What cause fragile X syndrome?
The fragile X syndrome is a genetic disorder caused by mutation of the FMR1 gene on the X chromosome.
Is fragile x bad?
yes
What is the life expectancy of a person with fragile x syndrome?
Early diagnosis and intensive intervention offer the best prognosis for individuals with fragile X syndrome. Adults with fragile X syndrome may benefit from vocational training and may need to live in a supervised setting. Life span is typically normal
When and by who was Fragile X Discovered?
Fragile x syndrome was first described in 1943 by J.Purdon Martin and Julia Bell whose family had eleven members with fragile x symptoms although they did not know the cause or have a name for the condition at this time. In 1969, Fragile x was first discovered under the microscope by a scientist called Herbert Lubs who discovered that one of the arms of the X chromosome in people with fragile x was constricted which gave it the appearance of being broken which is how the name 'fragile x' came about. In 1991 Verkerk identified the cause for transcriptional silencing of the gene Fmr-1, that encodes the protein FMRP.
