O-090 Correcting a PLC ζ mutation in the human germ line to overcome hereditary infertility

AbstractStudy questionCan clustered regularly interspaced short palindromic repeats (CRISPR)/Cas9 gene editing result in the correction of a single base pair substitution that causes male infertility?Summary answerCRISPR/Cas9 administration during intracytoplasmic sperm injection (ICSI) leads to correction attempts of mutant phospholipase C zeta (PLC ζ), howeverc loss-of-heterozygosity (LOH).What is known alreadyFailed fertilization after ICSI can be caused by mutations in the sperm-related oocyte factor PLC ζ which can be overcome by assisted oocyte activation (AOA). In this way, children may inherit the infertility-causing mutation. Mutation transmission can be overcome through CRISPR/Cas9 delivery during ICSI. In previous studies using CRISPR/Cas9 in the human germline for mutation correction, loss- of-heterozygosity (LOH, loss of the allele of one of the parents) was observed. Two different explanations were given, namely partial or complete paternal chromosomal loss or the correction of the mutation by using the maternal wild-type allele instead of the exogeneous supplied repair template.Study design, size, durationWe injected a gRNA-Cas9 protein complex to target the PLC ζ mutant allele, a repair template harboring the desired nucleotide substitution and an additional synonymous variant to track template usage, together with patient’s sperm. To overcome fertilization failure, AOA was applied during ICSI. After a culture period of maximal 6 days the embryos were c o...
Source: Human Reproduction - Category: Reproduction Medicine Source Type: research