Genetic Counseling

Personalized pre- and post-test counseling support

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FirstInsight

Non-invasive prenatal screening

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FirstDx

Whole exome sequencing solution

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FirstScreen

Comprehensive carrier screening

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FirstOnco

Hereditary cancer panel testing

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Fragile X Test 

Fragile X syndrome is a genetic condition which causes a range of developmental disabilities including learning disabilities and cognitive impairment. The condition results from a mutation in the FMR1 gene, affecting the production of the essential FMRP protein crucial for nerve communication. Fragile X syndrome is inherited in an X-linked dominant pattern which indicates that one copy of the altered gene in each cell is sufficient to cause the condition.
First Genomix utilizes Polymerase Chain Reaction (PCR) to analyse the CGG segment for abnormal trinucleotide repeat expansion (>200 times) within the FMR1 gene.

When is the Fragile X test offered?

Genetic testing for Fragile X is recommended in the following conditions:

  • When clinical symptoms are suggestive of Fragile X syndrome such as developmental delay and intellectual disabilities
  • Presence of Fragile X-associated tremor/ataxia syndrome (FXTAS)
  • Female infertility which could result from Fragile X-associated primary ovarian insufficiency (FXPOI)
  • Presence of a family history of Fragile X

How is the test performed?

The Fragile X test is an effective genetic tool for diagnosing Fragile X syndrome. The test accurately evaluates if the underlying cause of a child’s developmental delays, autism, or inherited intellectual disability is due to a mutation (abnormal trinucleotide repeat expansions) in the FMR1 gene. The test can also help determine if a person is a premutation carrier.

The genetic report provides details about the size of the repetitive sections detected through PCR analysis, which includes the number of CGG repeats within the FMR1 gene, based on the following interpretation standard:

  • Normal: <45 CGG repeats
  • Intermediate: 45-54 CGG repeats
  • Premutation: 55-200 CGG repeats
  • Full mutation ranges: >200 CGG repeats

Due to the complexity of Fragile X inheritance, genetic counselling sessions are offered by First Genomix to help families with a positive report in understanding the implications for the individual tested and for his/her extended family.