The authors used bioinformatic analysis to sort out variants that potentially affect splicing and then analyzed them using mini-gene assays.
The acronyms need to be explained. Not all readers are familiar with PTC (premature termination codon) and NMD (nonsense mediated decay); as some variants are found PTC-NMD, this needs to be explained better. I would also stress a little more that FL is almost undetectable.