However, this test does not detect a -thalassemia due to a point mutation. The turnaround time for the mutation panel is 2-3 working days. Hb electrophoresis data. This assay utilizes both a genomic Southern blot and a PCR assay to distinguish respectively methylation status and CGG repeat number of the FMR-1 gene which when mutated causes Fragile X syndrome. Both premutations and full mutations can be accurately detected.
Turnaround time is approximately one week.
Please note that direct testing from amniocytes or CVS cultures are not acceptable for this test. The splice acceptor site for exon 9 contains a series of T nucleotides that are polymorphic and occur commonly as 3 alleles. The variability of the number of T's at the acceptor site affects the efficiency of exon 9 splicing, such that 5T allele transcripts largely but not always miss exon 9 due to alternate splicing. Transcripts that lack exon 9 result in a non or partly functional CFTR protein. The severity of the CF phenotype is related to the amount of normal CFTR protein produced.