Long-Read RNA Sequencing Reveals Extensive Transcript Isoform Changes in a Patient with IFAP Syndrome with a Recurrent Intronic MBTPS2 Variant

A study on a patient with IFAP syndrome, characterized by ichthyosis, alopecia, and photophobia, identified a hemizygous intronic variant in the MBTPS2 gene. This variant, previously known to cause a 20-base skipping in exon 7, was further investigated using long-read RNA sequencing. The analysis revealed additional skipping of exons 6 and 7 and a significant reduction in normal transcript expression compared to healthy skin. This highlights the utility of long-read RNA sequencing in identifying diverse transcript isoforms and understanding the impact of splice-altering variants.