Infertility is known to be associated with chromosomal aberrations. Here the author reviews hitherto yet published cases of infertility identified to be carriers of small supernumerary marker chromosomes (sSMC). According to the sSMC web page (http://ssmc-tl. com/Start.html) there are now 225 cases of sSMC detected and characterized for their chromosomal origin and genetic content in infertile but otherwise health persons. In 54% of the cases, sSMC originated from chromosome 15 or 14, and was parentally transmitted in over 50% of the infertile sSMC-carriers. To the best of the authors knowledge, this is the largest review of infertile sSMC-carriers ever done.
Chromosome Aberrations ; Genetic Markers ; Humans ; Infertility ; genetics

Male infertility is a worldwide problem, with a variety of causes including genetic factors. Sex chromosomes are particularly interesting, as males only have a single copy of both chromosomes. The Y chromosome is obviously an area of interest in the study of male-factor infertility because it contains many of the genes that are critical for spermatogenesis and the development of male gonads. Y chromosome microdeletions are the most commonly known genetic causes of spermatogenic failure in males. The azoospermia factor (AZF) region is a particular area on the long arm of the Y chromosome, Yq, where microdeletions occur most frequently. Fourteen Y chromosome genes encoding putatively functional proteins and expressed in the human testis are found to be located in one of the three AZF intervals. The exact role of specific AZF genes in spermatogenesis is largely unknown, for each of the most classical Yq deletions removes multiple genes. The importance of the X chromosome in mammalian spermatogenesis is suggested by its enrichment of germ cell-specific genes expressed in spermatogenesis, such as AR, USP26, TAF7L, TEX11, KAL1, AKAP4, and NXF2. Genes on the X chromosome may be under unique evolutionary pressure due to their hemizygous expression in male. The mutations in the single copy X-linked genes, unlike in autosomal genes, would not be masked by a normal allele. Many researches have been conducted on the relationship between spermatogenesis and the genes on the X chromosome, but the involvement of the X chromosome in male infertility remains less understood and deserves further characterization.
Humans ; Infertility, Male ; genetics ; Male ; Sex Chromosomes

The ubiquitin specific protease 26 (USP26) gene is located at Xq26.2 and present as a single exon on the X chromosome encoding for a protein of 913 amino acids. It belongs to a large family of deubiquitinating enzymes, and is exclusively expressed in the testis. There are conflicting reports on whether mutations in USP26 are associated with male infertility. This article updates the researches on the USP26 gene, its complicated relationship with male spermatogenesis dysfunction, the role of its mutation in male infertility, its geographical or ethnic distribution, and its evolution.
Cysteine Endopeptidases ; genetics ; Humans ; Infertility, Male ; genetics ; Male ; Spermatogenesis ; genetics

Male infertility is a complex disease affecting the reproduction of childbearing couples, for which genetic polymorphism of spermatogenesis genes is an important genetic pathogenic factor. Lots of genes closely related with spermatogenesis have been successfully identified through the gene knockout technology. Spermatogenesis impairment related genes include those associated with expression enzymes, receptors, cell apoptosis, transcription regulation, and so on. The genetic susceptibility of these genes, infection, and environment jointly contribute to non-obstructive azoospermia and oligozoospermia in males. The analysis of the single nucleotide polymorphism (SNP) of spermatogenesis impairment related genes helps explain the possible mechanism of pathogenesis at the molecular level, and provides theoretical evidence for the clinical diagnosis and treatment of male infertility. The article focuses on the correlation of the SNPs of spermatogenesis impairment related genes with azoospermia and oligozoospermia.
Humans ; Infertility, Male ; genetics ; Male ; Oligospermia ; genetics ; Polymorphism, Single Nucleotide

Men with azoospermia or severe oligospermia (< 5 x 10(6)/ml) should have genetic testing to identify the reason for male infertility before treatment. Identification of obstructive azoospermia (OA) or non-obstructive azoospermia (NOA) is essential because genetic testing differs for OA (which has normal testicular function, testicular volume, and FSH) versus NOA (which has small, soft testes and increased FSH). Among patients with NOA, history and physical examination along with laboratory testing is required to choose genetic testing specifically for primary testicular failure or congenital hypogonadotropic hypogonadism (HH). Genetic testing options include cystic fibrosis transmembrane conductance regulator (CFTR) testing for men with OA due to congenital absence of the vas, while karyotype, Y chromosome microdeletions (YCMD), and other specific genetic tests may be indicated if patient has severe oligospermia or NOA. These genetic tests help to identify which patients may benefit from medical and/or surgical intervention. The most recent techniques for genetic analysis will improve diagnosis and management of male infertility.
Genetic Testing ; Humans ; Infertility, Male ; genetics ; Male ; Oligospermia ; genetics

Teratozoospermia is one of the important factors contributing to male infertility, and its pathogenesis is not yet clear. Recent years have witnessed some progress in the researches on sperm morphology, and some genes have been confirmed to be correlated with spermatogenesis. Aiming to provide some evidence for the pathogenesis of teratozoospermia, this paper reviews the relevant literature in the past five years addressing such special teratozoospermia as globozoospermia, nuclear vacuoles, decapitated spermatozoa, excessive residual cytoplasm, dysplasia of the fibrous sheath, and primary ciliary dyskinesia, and elaborates on the molecular genetic mechanisms of DPY19L2, AR, PRM1, GBA2, PCI, CREM, TH2A, TH2B, ODF1, Cntrob, OAZ-t, HOOK1, SPEM1, GAT1, PRSS21, 15-LOX, Sptrx, AKAP3, AKAP4, DNAI1, DNAH5, RSPH4A, TXNDC3, CCDC39, LRRC6, LRRC50, KTU and so on. Meanwhile, this review also presents an overview on the latest advances in assisted reproductive technology and its outcomes in the treatment of teratozoospermia patients in order to provide a theoretical basis for the diagnosis and treatment of male infertility.
Humans ; Infertility, Male ; genetics ; Male ; Membrane Proteins ; genetics ; Spermatozoa ; pathology

Humans ; Infertility, Male/genetics* ; Male ; Sperm Motility/genetics* ; Spermatozoa

Male ; Humans ; Azoospermia/genetics* ; Infertility, Male/genetics* ; Mutation ; Homozygote

Male ; Humans ; Avena ; Infertility, Male/genetics* ; Oligospermia/genetics* ; Asthenozoospermia ; Spermatozoa

Male infertility is a common complex disease. Y-linked spermatogenic failure is an important cause for this disorder. Due to the presence of many repeat sequences and the frequent occurrence of non-allelic homologous recombination between the sequences in the male-specific region of the Y (MSY) region of the chromosome, Y chromosome possesses high variation rate. The variations may result in the dosage changes of spermatogenesis-related gene families and lead to male infertility. The present article reviews the recent progress of the study on Y chromosome variations, and its possible effect on spermatogenic function, in DNA level.
Chromosomes, Human, Y ; genetics ; Haplotypes ; genetics ; Humans ; Infertility, Male ; genetics ; Male ; Mutation ; Spermatogenesis ; genetics