![]() ![]() Satisfied, he waddled over to the couch and curled up to watch Lucifer, an American show he’d slowly been working his way through on Netflix. He grabbed his current favorite cup, plastic with a straw and handle, and filled it. ![]() He opened the fridge and debated what he wanted, settling on a cup of juice. He walked into the den and turned the tv on before going over to the kitchen. Yawning, he quietly padded out of his room, pulling the door shut behind him. Feeling a little better already with the room better lit, he stood and stretched, making a face as various joints popped in response. He laid there for a moment, working up the energy, before slowly tilting himself into a sitting position and flicking his bedside light on. But it was unnerving and even though he was still so tired, eyelids fighting not close again, he didn’t want to go back to sleep. There wasn’t a serial killer chasing him or a monster eating him alive. He resisted though, rolling over and staring at the beam of light pouring in from the hallway through the crack he’d left in his door in his exhausted stumble over to his bed. The mutation in this study is most likely to abolish lariat formation because the artificial site of the high splice site score did not improve splicing efficiency.Yoongi came back to consciousness slowly, the dream clinging to him and threatening to pull him back under if he let it. The sequence around the adenosine -17 residue upstream of the normal acceptor splice site in this report, UGCAAU (-21 to -16), matches the consensus branchpoint sequence YNYRAY (Y, pyrimidine R, purine N, any base) reported in the literature. Of the total transcripts, 67% and 32% were correctly spliced in the normal chimeric construct and P417L, respectively, while no normally spliced product was generated either in the chimeric construct with -17 a->g or in that with a high splice site score. They, respectively, had the normal sequence, P417L (exon 11, +8 C->T), the intronic mutation (-17 a->g), and the intronic mutation with an artificially engineered intron 10/exon 11 junction of a higher splice site score (85.1). To test this hypothesis, we constructed four chimeric cDNAs all with an additional intron 10 inserted and evaluated their splicing efficiency. We noted an unusually low splice site score (61.8) for the exon 10/intron 11 junction and suspected that this might be partially responsible for the aberrant splicing in these mutations. This mutation caused abnormal 3' splicing at position -37 of intron 10, and no normally spliced product was detectable upon RT-PCR analysis. In the other two patients, a novel disease-causing base transition was found within intron 10, away from the intron/exon junction (-17 a->g). This finding suggests that S255R further reduces the catalytic activity of the already below-threshold amount of normally spliced mRNA and accounts for the more severe phenotype in our patients. An expression study of the normally spliced cDNA with the double and the triple mutations gave about 70% and 30% of normal activity, respectively. S255R is a novel mutation without prior description in the literature. The mild phenotype is attributed to the presence of a small amount of normally spliced mRNA. K121R is known to be a functional polymorphism, while P417L (exon 11, +8 C->T) generates predominantly an abnormally spliced mRNA at base +112 of exon 11 and has been described in two patients with a juvenile form of the disease. Two patients had complex base substitutions one patient was homoallelic for a triple mutation (P417L, K121R, and S255R) and the other was a compound heterozygote of a double (P417L and K121R) mutation and the triple mutation. Four unrelated Japanese patients with infantile Sandhoff disease (beta-hexosaminidase beta-subunit deficiency) have been studied for the molecular basis of their severe phenotype.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |