Infertility in humans is surprisingly common occurring in approximately 15% of the population wishing to start a family. Despite this, the molecular and genetic factors underlying the cause of infertility remain large...Infertility in humans is surprisingly common occurring in approximately 15% of the population wishing to start a family. Despite this, the molecular and genetic factors underlying the cause of infertility remain largely undiscovered. Nevertheless, more and more genetic factors associated with infertility are being identified. This review will focus on our current understanding of the chromosomal basis of male infertility specifically： chromosomal aneuploidy, structural and numerical karyotype abnormalities and Y chromosomal microdeletions. Chromosomal aneuploidy is the leading cause of pregnancy loss and developmental disabilities in humans. Aneuploidy is predominantly maternal in origin, but concerns have been raised regarding the safety of intracytoplasmic sperm injection as infertile men have significantly higher levels of sperm aneuploidy compared to their fertile counterparts. Males with numerical or structural karyotype abnormalities are also at an increased risk of producing aneuploid sperm. Our current understanding of how sperm aneuploidy translates to embryo aneuploidy will be reviewed, as well as the application of preimplantation genetic diagnosis （PGD） in such cases. Clinical recommendations where possible will be made, as well as discussion of the use of emerging array technology in PGD and its potential applications in male infertility.展开更多
Conventional PCR methods combined with linkage analysis based on short tandem repeats （STRs） or Karyomapping with single nucleotide polymorphism （SNP） arrays, have been applied to preimplantation genetic diagnosis...Conventional PCR methods combined with linkage analysis based on short tandem repeats （STRs） or Karyomapping with single nucleotide polymorphism （SNP） arrays, have been applied to preimplantation genetic diagnosis （PGD） for spinal muscular atrophy （SMA）, an autosome recessive disorder. However, it has limitations in SMA diagnosis by Karyomapping, and these methods are unable to distinguish wild- type embryos with carriers effectively. Mutated allele revealed by sequencing with aneuploidy and linkage analyses （MARSALA） is a new method allowing embryo selection by a one-step next-generation sequencing （NGS） procedure, which has been applied in PGD for both autosome dominant and X-linked diseases in our group previously. In this study, we carried out PGD based on MARSALA for two carrier families with SMA affected children. As a result, one of the couples has given birth to a healthy baby free of mutations in SMA-causing gene. It is the first time that MARSALA was applied to PGD for SMA, and we can distinguish the embryos with heterozygous deletion （carriers） from the wild-type （normal） ones accurately through this NGS-based method. In addition, direct mutation detection allows us to identify the affected embryos （homozygous deletion）, which can be regarded as probands for linkage analysis, in case that the affected family member is absent, In the future, the NGS-based MARSALA method is expected to be used in PGD for all monogenetic disorders with known pathogenic gene mutation.展开更多
文摘Infertility in humans is surprisingly common occurring in approximately 15% of the population wishing to start a family. Despite this, the molecular and genetic factors underlying the cause of infertility remain largely undiscovered. Nevertheless, more and more genetic factors associated with infertility are being identified. This review will focus on our current understanding of the chromosomal basis of male infertility specifically： chromosomal aneuploidy, structural and numerical karyotype abnormalities and Y chromosomal microdeletions. Chromosomal aneuploidy is the leading cause of pregnancy loss and developmental disabilities in humans. Aneuploidy is predominantly maternal in origin, but concerns have been raised regarding the safety of intracytoplasmic sperm injection as infertile men have significantly higher levels of sperm aneuploidy compared to their fertile counterparts. Males with numerical or structural karyotype abnormalities are also at an increased risk of producing aneuploid sperm. Our current understanding of how sperm aneuploidy translates to embryo aneuploidy will be reviewed, as well as the application of preimplantation genetic diagnosis （PGD） in such cases. Clinical recommendations where possible will be made, as well as discussion of the use of emerging array technology in PGD and its potential applications in male infertility.
基金supported by the National Natural Science Foundation of China (Nos. 31522034, 31571544 and 31230047)the National High Technology Research and Development Program (No. 2015AA020407)+1 种基金Beijing Municipal Science and Technology Commission (No. D151100002415004)Research Fund of National Health and Family Planning Commission of China (No. 201402004)
文摘Conventional PCR methods combined with linkage analysis based on short tandem repeats （STRs） or Karyomapping with single nucleotide polymorphism （SNP） arrays, have been applied to preimplantation genetic diagnosis （PGD） for spinal muscular atrophy （SMA）, an autosome recessive disorder. However, it has limitations in SMA diagnosis by Karyomapping, and these methods are unable to distinguish wild- type embryos with carriers effectively. Mutated allele revealed by sequencing with aneuploidy and linkage analyses （MARSALA） is a new method allowing embryo selection by a one-step next-generation sequencing （NGS） procedure, which has been applied in PGD for both autosome dominant and X-linked diseases in our group previously. In this study, we carried out PGD based on MARSALA for two carrier families with SMA affected children. As a result, one of the couples has given birth to a healthy baby free of mutations in SMA-causing gene. It is the first time that MARSALA was applied to PGD for SMA, and we can distinguish the embryos with heterozygous deletion （carriers） from the wild-type （normal） ones accurately through this NGS-based method. In addition, direct mutation detection allows us to identify the affected embryos （homozygous deletion）, which can be regarded as probands for linkage analysis, in case that the affected family member is absent, In the future, the NGS-based MARSALA method is expected to be used in PGD for all monogenetic disorders with known pathogenic gene mutation.
