Jacquelin HoPeriod 2April 7th, 2014

FRAGILE X SYNDROME

Introduction

History:1943 Martin/Bell discover X-linked form of mental retardation,

1969 Herbert Lubs develops chromosomal test to identify Fragile X,

1991 FMR1 gene causing Fragile X syndrome is discovered (World, 2012).

Current presence:1 in 250 females and 1 in 800 males carry the mutation, and it affects all ethnic groups (Hagerman et al., 2004)

According to the US National Library of Medicine (2012), Fragile X Syndrome is a mutation affecting the X chromosome.

The mutation involves abnormally high amounts of the repeat of CGG in the FMR1 gene:55-200 repeats: carrier>200: full mutation, FMR1 ceases to function(Hagerman P., Hagerman R., 2004)

It is known as the most common form of inherited mental retardation.

Symptoms and Treatment- Normal at birth- Delayed development- Mental impairment- Attention deficit or

hyperactivity- Frequent ear/sinus

infections- Nearsightedness- Lazy eye- Seizures

Treated with:- Speech, occupational, or

physical therapy

Currently no cure

(Sherman et al., 2005)

http://jmg.bmj.com/content/39/3/200/F1.large.jpg

Prevention and Inheritance

Females can only inherit Fragile X from either parent.Males can only inherit the Fragile X gene from their mother.

Fragile X is a mutation associated with the X chromosome.

Men carrying pre-mutations of Fragile X are usually stable (Sherman et al., 2005).

Males affected by Fragile X espoused to healthy females will have carrier daughters and healthy sons.

Females carriers espoused to healthy males may have affected sons. (See Figure on right)

http://upload.wikim

edia.org/wikipedia/com

mons/a/a3/XlinkRecessive.jpg

Personal ReflectionLike many other mental disorders, people affected by Fragile X

syndrome are at risk of aggression, emotional instability, and autism. Though there is currently no cure, various support programs are available for those diagnosed with Fragile X and family members and caretakers of the affected individual.

Fragile X is surprisingly common, even more so considering how many people affected or carrying it are unable or simply choose to not reproduce and avoid the risk of passing the disorder on to their children.

In researching Fragile X, I was moved by words of advice and the optimistic outlook of mothers caring for their autistic children. A strong bond of fellow caretakers has developed across the internet. General themes that appear in their stories include perseverance and unconditional love.

Article Analysis Though autism is a common symptom for those with Fragile X, new studies show that the autism associated with Fragile X differs from what is normally observed.

Young autistic boys with and without Fragile X were observed in a recent test study. Those with Fragile X tended to be more interested in social contact though ended up shying away due to anxiety.

This study also shows why normal treatment for autism has shown to not be as affective in the case of Fragile X autism.

Wright, J. (2014, March 21). Clinical research: Symptoms of fragile X, autism diverge. Simons Foundation Autism Research Initiative. Retrieved April 7, 2014, from https://sfari.org/news-and-opinion/in-brief/2014/clinical-research-symptoms-of-fragile-x-autism-diverge

ReferencesFragile X syndrome. (2012, April 12). In World of Genetics. Gale. Retrieved from http://ghr.nlm.nih.gov/condition/fragile-x-syndrome

Hagerman, P., & Hagerman, R. (2004, August). National Center for Biotechnology Information. Retrieved April 6, 2014, from http://www.ncbi.nlm.nih.gov/pubmed/15052536?dopt=Abstract

Sherman, S., Pletcher, B., & Driscoll, D. (2005 October). Result Filters. National Center for Biotechnology Information. Retrieved April 6, 2014, from http://www.ncbi.nlm.nih.gov/pubmed/16247297?dopt=Abstract