In-frame insertion of 12 bp (CATCCATCCATC) between 4:838701..838702 , SNPs 838699 G to T, 838697 T to C, and 838696 A to C resulting in the addition of 4 amino acids (SIHP) between amino acids 103 and 104, amino acid 104 V to F, and amino acid 105 N to H in the only isoform (RA).