Teratozoospermia is characterized by the presence of spermatozoa with abnormal morphology over 85 % in sperm. When all the spermatozoa display a unique abnormality, teratozoospermia is said to be monomorphic. Two forms of monomorphic teratozoospermia, representing less than 1 % of male infertility, are recognized: macrozoospermia (also called macrocephalic sperm head syndrome) and globozoospermia (also called round-headed sperm syndrome). Macrozoospermia is defined as the presence of a very high percentage of spermatozoa with enlarged head and multiple flagella. Meiotic segregation studies in 30 males revealed that over 90 % of spermatozoa were aneuploid, mainly diploid. Sperm DNA fragmentation studies performed in a few patients showed an increase in DNA fragmentation index compared to fertile men. Four mutations in the AURKC gene, a key player in meiosis and more particularly in spermatogenesis, have been found to be responsible for macrozoospermia. Globozoospermia is characterized by round-headed spermatozoa with an absent acrosome, an aberrant nuclear membrane and midpiece defects. The rate of aneuploidy of various chromosomes in spermatozoa from 26 globozoospermic men was slightly increased compared to fertile men. However, this increase was of the same order as that commonly found in infertile men with altered sperm parameters. The majority of the studies found that globozoospermic males had a sperm DNA fragmentation index higher than in fertile men. Mutations or deletions in three genes, SPATA16, PICK1 and DPY19L2, have been shown to be responsible for globozoospermia. Identification of the genetic causes of macrozoospermia and globozoospermia should help refine diagnosis and treatment of these patients, avoiding long and painful treatments. Elucidating the molecular causes of these defects is of utmost importance as intracytoplasmic sperm injection (ICSI) is very disappointing in these two pathologies.
Infertility is estimated to affect up to 15% of couples of reproductive age. Among the male factors, globozoospermia (also called round-headed sperm syndrome) is a rare type of teratozoospermia accounting for <0.1% of male infertility. Lack of acrosome, whose production is a postmeiotic event in spermatogenesis, and round sperm head are its main characteristics. The acrosomeless spermatozoon is unable to go through the zona pellucida and fuse with the oolemma of the oocyte, and fertilisation failures have been attributed to a deficiency in oocyte activation capacity, even when intracytoplasmic sperm injection (ICSI) is attempted. The pathogenesis of this anomaly is still unclear but genetic factors are likely to be involved. DNA fragmentation rate has been reported for 16 globozoospermic males, usually using the terminal uridine nick-end labelling (TUNEL) assay. Most of the patients had a DNA fragmentation index (DFI) higher than that in fertile men. The rate of aneuploidy for some specific chromosomes was increased in 12 among the 26 globozoospermic males reported in the literature. The same results (high DFI and aneuploidy rates) were observed in infertile males compared to fertile men, notably in those with oligoasthenozoospermia or teratozoospermia, independently of the origins. Mutations or deletions in three genes, SPATA16, PICK1 and DPY19L2, have been shown to be responsible for globozoospermia. Proteins coded by the first two genes localise to the Golgi apparatus and the proacrosomal granules that are transported in the acrosome. It is likely that other proteins involved in the acrosome formation remain to be identified.
cancérologie, UMR892, UFR Médecine et Techniques médicales, Nantes, France NK-cell function is regulated by a balance between inhibitory and activating killer cell immunoglobulin-like receptors (KIR) that specifically recognize HLA class I molecules. Using KIR-specific mAb to discriminate between KIR2DS1 and KIR2DL1 receptors, we show that KIR2DS1 + NK cells are C2-alloreactive only from C2 À individuals. Moreover, using an in vitro model of NK-cell expansion, we show here that the frequency of KIR2DL1 + NK cells is significantly higher in the absence of C2 ligand on stimulator EBV-B cells than in its presence. This observation was made regardless of the presence or absence of the autologous C2 ligand, suggesting that the C2 À EBV-B stimulator cells used in this in vitro model could activate unlicensed KIR2DL1 + NK cells. In the case of KIR2DL1 + /S1 + genotyped individuals, KIR2DS1 + NK-cell frequency was increased after stimulation with C2 + compared with C2 À stimulator B cells, but only from C2 À individuals. Altogether, these data highlight the C2 alloreactivity of KIR2DS1 + NK cells that is only observed in C2 À individuals. These results provide new insights into the way in which NK KIR cell expansion might be regulated in an allogeneic environment.
Unlike the small proximal 15q deletions causing Prader-Willi and/or Angelman syndrome, distal deletions of the terminal long arm of chromosome 15 have rarely been described. To the best of our knowledge, only four patients with a pure terminal 15q deletion have been documented in the literature. We report here on an unexpected abnormal hybridization pattern for the 15q specific subtelomeric control probe (clone 154P1) of the commercial SNRPN probe in a girl referred for suspicion of Angelman syndrome. Investigation by fluorescent in situ hybridization (FISH) using bacterial artificial chromosome (BAC) clones defined a partial monosomy 15q26.2 --> 15qter for a minimal critical region of approximately 5.7 Mb, which is the most distal de novo 15qter deletion reported to date. All the de novo 15qter deletion cases, including ours, presented with pre- and post-natal growth retardation related to the loss of one copy of the IGF1R gene. Based on the comparaison with the previous published cases and owing to the clinical phenotype of our patient, we define a new subtelomeric 15qter syndrome which would be characterized by intrauterine growth retardation and global post-natal growth failure, variable mental retardation, facial anomalies including relative micrognathia and triangular facies and minor malformations of the extremities including proximally placed thumbs, cubitus valgus, and brachydactyly with tappering of the digits.
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