The Research Of Y Chromosome Microdeletions And Karyotype Analysis Of Chromosomes In 313 Infertile Men

Objective: According to WHO statistics, there are about 15% of infertile couples of reproductive age, about half of which is caused by the man, or a relationship with the man. Genetic defects occurred in more than 30% in all of the male infertility. Y chromosome microdeletion is the second factor which caused male infertility except Klinefelter syndrome. However the microdeletion rate was reported about 1%-55.5%.As is known to all, Y chromosome is relevant to reproduction. People realized that Y chromosome microdeletion was related with sperm production disorders in 1970. In 1976 Tiepolo and Zuffardi found Y-chromosome microdeletions in 6 patients with idiopathic azoospermia. It is the first proof that genetic factors was responsible for spermatogenic, they also reported that azoospermia factor exist in Yq, after that the research become hot spot at home and abroad. The AZF was divided into three non-overlapping areas: AZFa, AZFb and AZFc, the microdeletions often occur in AZFc and AZFb. In 1999 Kent-First found AZFd between AZFb and AZFc, they think there are some spermatogenics gene in this area.The study showed that patients with AZFabc united microdeletions usually have no sperm at all, 96% patients with idiopathic azoospermia and 4% with oligozoospermia could be detected with AZFa microdeletion and AZFbc united microdeletions. ICSI, Intracytoplasmicsperm injection is a revolutionary breakthrouth for the therapy of male infertility, it is possible for patients with idiopathic azoospermia and oligozoospermia to have their child, but genetic defects could be transmitted vertically to their child and the next generation may be even worser than their farther. These people must be carried out prenatal diagnosis before ICSI, in this way we can avoid the vertical transmission of genetic defects. Genetic counseling and screening is very important for these patients, and microdeletion rate and dimension are considered by doctors and patients, so the detection of Y chromosome microdeletion is very important for clinical application.Abnormality of chromosome karyotype is one of the key factors of infertility, composed of Klinefelter syndrome, autosomal polymorphism, chromosome structural aberrations and large Y chromosome.Klinefelter syndrome is the most common genetic factor of male infertility. Parents with chromosome abnormalities can bring the genetic defects to their child vertically and the next generation may be even worser than their farther. Karyotype analysis of chromosomes is very important for prenatal and postnatal care.Our aim is to study Y chromosome microdeletions in patients with idiopathic azoospermia and oligozoospermia, and to evaluate the microdeletion, summarize the distribution rules of Y chromosome microdeletions and male infertility in our region. At the same time, we evaluate relationship between Y chromosome microdeletions and karyotype analysis of chromosomes.Methods:1 Acording to EAA/EMQN best practice guidelines for molecular diagnosis of Y-chromosome microdeletions (2004) and the research at home and abroad, we choose the Micro Del in Y Chromosome & male yeld Test Kit of Yaneng Bioscience(ShenZhen) Co, LTD, use 16 STS of Y chromosome in AZFa, AZFb, AZFc and AZFd for the detections of Y-chromosome microdeletions. 140 patients with idiopathic azoospermia and 173 with oligozoospermia are detected in our research, 45 normal fertility men and 5 healthy females were detected as controls.2 To analyze the chromosome karyotype of peripheral lymphocytes in 286 patients by G-banding.Results:1 All samples were detected by multiplex PCR technique, we found SY14 in all of them, we can confer that all DNA templet meet our requirements, and the amplification was effective.2 We detected 32 Y chromosome microdeletions in 313 patients with spermatogenic, the microdeletion rate was 10.22%. There were 25 in azoospermia and 7 in oligozoospermia patients with microdeletions, and the microdeletion rates were 17.86% (25/140) and 4.05% (7/173) respectively. No microdeletions were found in normal controls, and there is no band in negative and blank controls.3 Analyzing Y-chromosome microdeletions by AZF, we found one microdeletion in AZFb and 20 patients with AZFcd united microdeletions, we also detected 5 patients with AZFabcd microdeletions and 6 with AZFbcd united microdeletions. Above all, AZFcd united microdeletions is the most common style, the microdeletion rate is 62.5%(20/32).4 While analyzing Y chromosome microdeletions in 313 patients, we choose 286 patients to analyze the chromosome karyotypes of peripheral lymphocytes by G-banding. 33 cases with abnormal chromosome karyotype were diagnosed. The abnormal rate was 11.54%. We detected 14 patients with Klinefelter syndrome, the karyotype is 47, XXY; 3 of sex reversal, chromosome karyotype is 46, XX; there is one patients with 47, XYY, he has an excess Y chromosome. Furthermore we found some other abnormal chromosome karyotype, for example, mosaic, balanced translocation and inversion.Conclusions:1 We detected 32 Y chromosome microdeletions in 313 patients with spermatogenic, the microdeletion rate was 10.22%. The result accorded with the data of reported.2 The patients with Y-chromosome microdeletion can bring the genetic defects vertically to male offspring, so it is important for them to detect Y-chromosome microdeletion before ICSI, in this way we can avoid the genetic defects to be passed to the next generation.3 There is relationship between Y chromosome microdeletion and chromosome karyotypes. However, they can not replace each other, it is suggested to detect them together for male infertility.