Preimplantation testing for phenylketonuria Yury Verlinsky, Ph.D., Svetlana Rechitsky, Ph.D., Oleg Verlinsky, Charles Strom, M.D., Ph.D., Anver Kuliev, M.D., Ph.D.  Fertility and Sterility  Volume 76, Issue 2, Pages 346-349 (August 2001) DOI: 10.1016/S0015-0282(01)01912-4

Figure 1 Schematic diagram of heminested polymerase chain reaction for maternal R408W and paternal Y414C mutations in the phenylalanine hydroxylase gene. Top. Map of human phenylketonuria (PKU) gene showing sites and location of short tandem repeats (STR), variable nucleotide tandem repeats (VNTR), restriction-fragment length polymorphisms (RFLPs), and maternal and paternal mutations. Bottom. Schematic representation of polymerase chain reaction products after first-round amplification with outside primers PKU-A and PKU-B (136 base pairs [bp]) and second-round heminested amplification with primers PKU-A and 414RS. Verlinsky. Preimplantation testing for phenylketonuria. Fertil Steril 2001. Fertility and Sterility 2001 76, 346-349DOI: (10.1016/S0015-0282(01)01912-4)

Figure 2 Preimplantation diagnosis for maternal mutation in the phenylalanine hydroxylase gene. Top. Schematic representation of maternal haplotypes. The heterozygous mother has the R408W mutation linked to short tandem repeats (STR) in intron 3, a variable number of tandem repeats (VNTR) close to the 3′ region of the gene (3 rep), and restriction fragment length polymorphism (RFLP) in intron 8 (-Site). Bottom. Genotyping oocytes by sequential PB1 and PB2 analysis for the R408W mutation and informative linked markers—STR, VNTR, and RFLP. All series include PB1 followed by PB2 in lane to its immediate right, corresponding to 11 oocytes studied (oocytes are numbered at the bottom). Because the R408W mutation creates a restriction site for the StyI enzyme, oocytes 2, 3, 4, 7, 9, and 15 were predicted to be normal on the basis of a heterozygous PB1 and a homozygous PB2. Oocyte 5 was predicted to be normal on the basis of homozygous mutant PB1 and normal PB2; this was in agreement with results of marker analysis, excluding the possibility of allele drop-out in the corresponding PB1. Drop-out of mutant allele is evident from the identical genotype of both PB1 and PB2 in oocyte 11 (confirmed by all three markers), suggesting that the oocyte is affected. The other 3 affected oocytes were predicted to be mutant on the basis of a heterozygous PB1 and a normal PB2 (oocytes 1 and 12) or a homozygous normal PB1 and a mutant PB2 (oocyte 13). Allele drop-out was also detected in oocytes 7 and 15 (identical genotype of PB1 and PB2 for intron 3 STR). These findings are not in conflict with the unaffected genotype of resulting embryos, which were transferred together with other two unaffected embryos (number 2 and 4). Verlinsky. Preimplantation testing for phenylketonuria. Fertil Steril 2001. Fertility and Sterility 2001 76, 346-349DOI: (10.1016/S0015-0282(01)01912-4)