Triplet Repeat Expansions
Triplet/Trinucleotide repeat expansions are analysed through the technique known as TP-PCR (Triplet repeat Primed Polymerase Chain Reaction).
Tests Offered
1. Fragile X
This test is used to determine the number of CGG trinucleotide repeats in order to establish a diagnosis of Fragile X syndrome. The technique is used specifically for the diagnosis of Fragile X syndrome, and Fragile X-associated disorders like Fragile X-associated Tremor/Ataxia syndrome (FXTAS) or Fragile X-associated Primary Ovarian Insufficiency (FXPOI), as well as for carrier testing for adults of reproductive age.
Acceptable sample
- Blood EDTA
2. Spinocerebellar Ataxia Panel
Spinocerebellar Ataxia (SCA) is a heterogeneous group of neurodegenerative disorders with variable expression and phenotypic overlap. In this test we screen for 7 common types of SCA for the presence of nucleotide repeat expansion. The genes ATXN1, ATXN2, ATXN3, CACNA1A, ATXN7 and PPP2R2B are screened for the presence of expansion in CAG repeat pertaining to SCA1, SCA2, SCA3, SCA6, SCA7 and SCA12 respectively. The ATXN10 gene is screened for presence of expansion in ATTCT repeats pertaining to SCA10.
Ataxia Spinocerebellar/SCA - Triplet Repeat (SCA2/12)
Acceptable samples
- Blood EDTA
Ataxia Spinocerebellar /SCA-Triplet Repeat (SCA 1, 2, 3, 6, 7, 12, 10 )
Acceptable samples
- Blood EDTA
3. Huntington Disease
This test is used to determine the expansion of CAG repeat in the HTT gene. This test is specifically design for screening of Huntington disease. The scope of this assay is limited to repeat expansion analysis of this gene and may not reveal the exact number of repeats present in large expansions.
Acceptable sample
- Blood EDTA