Validation and first clinical application of karyomapping for preimplantation diagnosis (PGD) of Gaucher disease combined with 24 chromosome screening

Abstract

OBJECTIVE: Validation and clinical application of genome wide single nucleotide polymorphism (SNP) genotyping and karyomapping for PGD of Gaucher disease combined with 24 chromosome aneuploidy screening.DESIGN: Analysis of SNP markers in family members and parents to validate the use of karyomapping and clinical application for PGD of Gaucher disease in parallel with conventional methods and array comparative genomic hybridisation (aCGH).MATERIALS AND METHODS: A couple at risk of Gaucher Disease underwent two cycles of PGD with informed consent (IRB#6902 NYU Langone Medical Center). Following whole genome amplification (Sureplex), SNP genotyping (Illumina HumanCytoSNP-12) of the embryo samples and parental and grandparental DNA, karyomap analysis was carried out. In addition, aCGH (BlueGnome) and direct mutation and linked marker analysis was performed on the WGA products. SNP genotypes were further analysed for a range of single gene defects.RESULTS: Highly accurate linkage based diagnosis of a range of single gene defects was demonstrated with only a minority of examples in which crossovers within or closely flanking the gene would prevent diagnosis. Karyomap analysis of 6 blastocysts demonstrated that one was unaffected, three were carriers and two were affected. All but one had chromosomal abnormalities including maternal trisomy 15, maternal monosomy 10, 20, 21 and 22 and a partial deletion of the paternal chromosome 11p. Multiple chromosome aneuploidies were detected in the arrested embryos including 4 with maternal monosomy 22 and paternal monosomy 2 and 16. Karyomap results were confirmed via mutation analysis and aCGH.CONCLUSION: Karyomapping combines accurate analysis of single gene defects and chromosome abnormalities including whole chromosome aneuploidies and partial deletions with their parental origin. The prevalence of chromosomal abnormalities in this patient's embryos underlines the importance of combined analysis for PGD. OBJECTIVE: Validation and clinical application of genome wide single nucleotide polymorphism (SNP) genotyping and karyomapping for PGD of Gaucher disease combined with 24 chromosome aneuploidy screening. DESIGN: Analysis of SNP markers in family members and parents to validate the use of karyomapping and clinical application for PGD of Gaucher disease in parallel with conventional methods and array comparative genomic hybridisation (aCGH). MATERIALS AND METHODS: A couple at risk of Gaucher Disease underwent two cycles of PGD with informed consent (IRB#6902 NYU Langone Medical Center). Following whole genome amplification (Sureplex), SNP genotyping (Illumina HumanCytoSNP-12) of the embryo samples and parental and grandparental DNA, karyomap analysis was carried out. In addition, aCGH (BlueGnome) and direct mutation and linked marker analysis was performed on the WGA products. SNP genotypes were further analysed for a range of single gene defects. RESULTS: Highly accurate linkage based diagnosis of a range of single gene defects was demonstrated with only a minority of examples in which crossovers within or closely flanking the gene would prevent diagnosis. Karyomap analysis of 6 blastocysts demonstrated that one was unaffected, three were carriers and two were affected. All but one had chromosomal abnormalities including maternal trisomy 15, maternal monosomy 10, 20, 21 and 22 and a partial deletion of the paternal chromosome 11p. Multiple chromosome aneuploidies were detected in the arrested embryos including 4 with maternal monosomy 22 and paternal monosomy 2 and 16. Karyomap results were confirmed via mutation analysis and aCGH. CONCLUSION: Karyomapping combines accurate analysis of single gene defects and chromosome abnormalities including whole chromosome aneuploidies and partial deletions with their parental origin. The prevalence of chromosomal abnormalities in this patient's embryos underlines the importance of combined analysis for PGD.