This technology includes a new set of synthetic PCCB genes that can be used to treat propionic acidemia (PA) caused by propionyl-coA carboxylase beta (PCCB) mutations. The amino acid sequence of PCCB was reverse translated, using a variety of algorithms and expert input, to generate novel DNA sequences encoding PCCB (synPCCB1-5) expected to have increased expression. Next, the synPCCB sequences were cloned into a canonical adeno-associated virus (AAV) vector and tested for expression in human cells to demonstrate that the codon optimized alleles showed improved expression compared to the wild type (WT) PCCB gene. Finally, a synPCCBl AAV was pseudoserotyped with a serotype 9 capsid and used to rescue Pech-I- knock-out mice from neonatal lethality and improve their clinical and metabolic phenotypes.
As these alleles are synthetic and express at higher levels than the WT PCCB allele, they have multiple advantages such as being useful for genomic medication applications, creation of vectors for genome editing, and specific nucleotide based-assays are possible for improved detection of the DNA and RNA expressed from these genes.