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PubMed2004

Genomic organization and evolution of the NF1 microdeletion region.

Five to 10% of neurofibromatosis type 1 (NF1) individuals have a microdeletion (1.5 Mb) encompassing the entire NF1 region and neighboring genes. Microdeletion patients have a distinct phenotype with a more severe tumor burden. Most of the microdeletion breakpoints cluster in flanking paralogous regions (NF1REPs). We describe the complete genomic region covering the NF1 microdeletion and an extensive analysis of the genomic and transcriptional organization of the NF1REPs. The flanking NF1REPs have a total length of about 75 kb and are composed of several fragments. One of these fragments originated from chromosome 19 and contains a hot spot for microdeletion breakpoints. The analysis of the genomic organization of the NF1 microdeletion region and of the NF1REPs in particular is important for understanding the mechanism by which NF1 microdeletions are formed. This analysis will also help to identify loci potentially involved in the pathogenesis of the increased tumor load and malignancy risk observed in NF1 microdeletion patients.

Animals↗
PubMed2006

Chromosomal abnormality and Y chromosome microdeletion in Chinese patients with azoospermia or severe oligozoospermia.

Chromosomal abnormality and Y chromosome microdeletion are regarded as two frequent genetic causes associated with spermatogenic failure in Caucasian population. To investigate the distribution of the two genetic defects in Chinese patients with azoospermia or severe oligozoospermia, karyotype analysis by G-banding was carried out in 358 idiopathic infertile men, including 256 patients with azoospermia and 102 patients with severe oligozoospermia, and screening of AZF region microdeletion of Y chromosome by multiplex PCR was performed in those patients without detectable chromosomal abnormality and 100 fertile controls. Of 358 patients, 39(10.9%) were found to have chromosomal abnormalities in which Klinefelter's syndrome (47, XXY) was the most common chromosomal aberration. The incidence of sex chromosomal abnormality in patients with azoospermia was significantly higher than that in patients with severe oligozoospermia (12.1% vs 1%). Among the rest of the 319 patients with normal karyotype, 46 (14.4%) were found to have microdeletions in AZF region. The prevalence rates of AZF microdeletion was 15% and 13.1% in patients with azoospermia and severe oligozoospermia respectively. The microdeletion in AZFc was the most frequent deletion and all the microdeletions in AZFa were found in azoospermic patients. No microdeletion in AZF region was detected in fertile controls. In conclusion, chromosomal abnormality and AZF region microdeletion of Y chromosome might account for about 25% of Chinese infertile patients with azoospermia or severe oligozoospermia, suggesting the two abnormalities are important genetic etiology of spermatogenic failure in Chinese population and it is essential to screen them during diagnosis of male infertility before in vitro assisted fertilization by introcytoplasmic sperm injection.

Adult↗
PubMed2002

Y-chromosome microdeletions and cytogenetic findings in unselected ICSI candidates at a Danish fertility clinic.

PURPOSE: To determine the frequency and type of microdeletions on the Y chromosome, and to evaluate cytogenetic findings in unselected ICSI candidates at a Danish Fertility Clinic. METHODS: Genomic DNA was extracted from blood samples, which were collected prospectively from 400 ICSI candidates attending the Fertility Clinic at Aarhus University Hospital, Denmark. Twenty-five sequence tagged sites (STSs) spanning the azoospermia factor (AZF) regions of the Y chromosome were amplified in 5 multiplex sets to investigate Y microdeletions. Semen analysis, karyotype analysis, and histological evaluation of testicular biopsies were also performed. RESULTS: Y microdeletions were detected in 3 (0.75%) of 400 unselected ICSI candidates. The frequency of Y microdeletions was found higher in azoospermic men (2%) than in oligozoospermic men (0.6%). Two patients having oligozoospermia had Y microdeletions in the AZFc region only, whereas the patient having azoospermia had Y microdeletions spanning the AZFb and AZFc regions. No microdeletion was detected in the AZFa region. Chromosomal anomalies were found in 6.1% of azoospermic men and in 2.7% of oligozoospermic men. A high frequency of cytogenetic abnormalities was found in normozoospermic men with fertilization failure (7.4%). CONCLUSIONS: The frequency of Y microdeletions both in the unselected ICSI candidates and subgroups classified as azoospermic and oligozoospermic seems rather low compared to results of previous studies, which have been quite varying. It is possible that in addition to patient selection criteria, ethnical and geographical differences may contribute to these variations. Cytogenetic evaluation of normozoospermic men with fertilization failure seems indicated because of a high frequency of cytogenetic abnormalities.

Adult↗
PubMed2001

Prevalence of Y chromosome microdeletions in infertile men who consulted a tertiary care medical centre: the Münster experience.

The long arm of the human Y chromosome is required for male fertility. Microdeletions in three different regions of the human Y chromosome, designated AZFa, AZFb and AZFc, respectively, are frequently associated with male infertility. The varying frequency of Y microdeletions found in cohorts of infertile men (0.4-55.5%) is probably related to the criteria by which the patients are selected. We report the diagnosis of Y chromosomal microdeletion in a total of 1,470 men who attended our infertility clinic, the largest sample of infertile patients to have been analysed to date. This cohort consists of three populations. The first subgroup comprises 228 selected patients with severely impaired spermatogenesis. Since microdeletions had also been reported in patients with less severe defects in spermatogenesis, we then intended to define the deletion frequency in unselected patients (population II: 378 patients). Population III comprises 864 prospectively selected patients and intracytoplasmic sperm injection candidates. Altogether, 19 patients with microdeletions were found (1.3%). The microdeletion frequencies in populations I, II and III were 3.5%, 0.3% and 1.2%, respectively. Our study helps to define a subgroup of infertile men at risk of Y chromosomal microdeletions, and strongly supports the recommendation that Y microdeletion analysis should be limited to azoospermic and severely oligozoospermic men and candidates for intracytoplasmic sperm injection.

Adult↗
PubMed2005

Prospective assessment of Y-chromosome microdeletions and reproductive outcomes among infertile couples of Japanese and African origin.

BACKGROUND: To compare the frequency of Y-chromosome microdeletions in Japanese and African azoospermic and oligozoospermic men and describe embryo characteristics and reproductive outcome following in vitro fertilization (IVF) with intracytoplasmic sperm injection (ICSI). METHODS: Our study was performed prospectively at two centers, a private IVF clinic and a university hospital. Japanese and African (Tanzanian) men with nonobstructive azoospermia (NOA) and oligozoospermia (concentration < 5 x 10(6) /ml) were evaluated for Y-chromosome microdeletions (n = 162). Of the 47 men with NOA, 26 were Japanese and 21 were Africans. Of the 115 men with oligozoospermia, 87 were Japanese and 28 were Africans. Reproductive outcomes of patients with Y-chromosome microdeletions were then compared with those of 19 IVF+ICSI cycles performed on couples with Y-chromosome intact males/tubal factor infertility which served as a control group. RESULTS: Seven azoospermic and oligozoospermic patients had Y-chromosome deletions; the total number of deletions in the AZFc region was five. There was only one deletion in the AZFa region and one complete deletion involving all three regions (AZFa, b, and c) within AZF. In our study population, microdeletion frequency among Japanese men was 6.2% (95% CI, 4.25%-14.45%), whereas no deletions were identified in the African group (95% CI, 0.0%-7.27%). The difference between the two groups was not statistically significant, however. Embryos derived from ICSI utilizing sperm with Y-chromosome microdeletion showed reduced rates of fertilization, blastocyst development, implantation, and pregnancy compared to the Y-chromosome intact group, although these observed differences were not statistically significant. CONCLUSION: The observed frequency of Y-chromosome microdeletion was 6.2% among Japanese azoospermic and oligozoospermic males; no microdeletions were identified among our African study patients. In this population of couples undergoing IVF+ICSI, there was no statistically significant difference in embryo characteristics or pregnancy outcome between patients with Y-chromosome microdeletion and those with an intact Y-chromosome.

Journal Article↗
PubMed2002

[Microdeletion syndromes].

New high-resolution cytogenetical technique identified an increased number of terminal, interstitial and subtelomeric microdeletion as the etiology of many syndromes of multiple congenital anomalies, mental retardation and facial dysmorphy. A loss of contiguous genes shows a high phenotypical variability and at the same time it is significant for genetic prognosis. 1) Variability of clinical features depends on the size and pathogenetic mechanism of underlying deletion; 2) Dysmorphic face features are of a characteristic type and can be somatoscopically recognized; 3) Heart defects and mental retardation are common features of microdeletion syndromes; 4) New mutations represent the most common etiology of microdeletions; only 1 to 10% of mutations are transmitted from the parental gonadal mosaics, from the balanced translocation or from the same microdeletion in parents; 5) Recurrence risk is low, but it may be as high as 50% in individual cases of inherited mutation; 6) Genetic heterogeneity is high and the responsible genes can be located at different chromosomes (e.g. Di George syndrome due to mutation on 22q or 10q) and can also result from microdeletion or point mutation (in the Shprintzen syndrome 70% represent microdeletion and 30% point mutation at 22q11, in Rubinstein-Taybi syndrome 10% cases result from microdeletions and 90% from point mutations); 7) Population incidence of microdeletions is high (1:4000 to 1:30,000) because their etiologic mechanism is related to the common unequal crossing over; 8) Imprinting plays a role in some cases, e.g. Prader-Willi syndrome results from nullisomy of paternal 15q12 chromosome, Angelman syndrome is related to that of maternal 15q12 chromosome; 9) Prenatal prevention of the high risk familial chromosomal rearrangements is feasible since the 12th gestation week.

Abnormalities, Multiple↗
PubMed2000

Y-chromosome microdeletion and its effect on reproductive decisions in taiwanese patients presenting with nonobstructive azoospermia.

OBJECTIVES: To investigate the position, extent, and frequency of Y chromosome microdeletions in Taiwanese patients presenting with nonobstructive azoospermia, and to investigate the effect of microdeletions on reproductive decisions. METHODS: We studied 176 consecutive men with azoospermia in our urology clinic. Polymerase chain reaction tests were performed in 94 patients with nonobstructive azoospermia, and a series of 27 sequence-tagged sites (STSs) mapped within intervals 5 and 6 of Yq11 was selected for analysis. Clinical genetics counseling was provided to couples with microdeletions, and these couples made their own choices about further treatment modalities. RESULTS: Among 94 patients screened for microdeletion, 11 (11.7%) showed microdeletions of one or more STSs. One had a deletion confined to the azoospermia factor b (AZFb) region (encompassing the RBM gene). Two were found to have deletions of both the AZFb and AZFc regions. Eight patients had deletions in the AZFc region (encompassing the DAZ gene). Five had deletions distal to the DAZ gene family. One had multiple, noncontiguous deletions. In 8 patients with testicular histology available, a lack of genotype/phenotype correlation was noted. Of the 11 couples with deletions, 3 thought microdeletion was a serious defect and opted for an artificial insemination of donor or adoption, 5 chose intracytoplasmic sperm injection, and the other 3 decided to undergo treatment with Chinese medicinal herbs. CONCLUSIONS: The most commonly deleted region in the Taiwanese population is AZFc. The genes implicated in Taiwanese spermatogenesis defects are the DAZ and RBM gene families. Twenty-seven percent of couples with microdeletions deferred assisted reproductive technologies because of concern about their underlying genetic defects.

Adoption↗
PubMed2002

A comparative study of Y chromosome microdeletions in infertile males from two Chinese populations.

PURPOSE: To compare the prevalence and type of Y-microdeletions in Hong Kong and Shanghai men with severe male-factor infertility. METHODS: Seven Y-linked sequence tagged site (STS) primers and seven gene-specific primers were screened in 293 infertile males (139 from Hong Kong and 154 from Shanghai) and 161 fertile men (61 from Hong Kong and 100 from Shanghai). Serum FSH, LH, and testosterone levels were also measured in these men. RESULTS: The incidence of Yq microdeletions in nonobstructive azoospermic men from Hong Kong (8.5%) and Shanghai (6%) was similar. Yq microdeletions were observed in severe oligospermic patients (8.5%) from Hong Kong but not from Shanghai. Among the 9 Hong Kong men with Y-microdeletions, 8 had AZFc deletion and one had AZFb deletion. In contrast, 6 of 9 men from Shanghai with Y-microdeletions had AZFb deletion. The incidence of AZFb deletion among Y-microdeleted men was statistically different between the two populations. Two of the men with AZFb deletion also had AZFa and AZFc deletions. CONCLUSIONS: Regional variations in the type of Y-microdeletion existed between Hong Kong and Shanghai infertile males.

Adult↗
PubMedDate not supplied

Evaluation of DAZ microdeletions in 34 infertile men.

Microdeletions in Yq11 are a common molecular cause of spermatogenic failure in men and are recurrently detected in about 10-15% of idiopathic azoospermia and severe oligozoospermia. Screening for AZF microdeletions is often performed by multiplex PCR. AZFc deletions, involving the DAZ gene, form the majority of these deletions. The aim of this study was to evaluate in a group of 34 Tunisian infertile patients (16 oligozoospermic and 18 azoospermic men) the prevalence of DAZ microdeletions using a rapid molecular strategy: the PCR-DGGE method based on the high degree of homology between the DAZ gene and its autosomally equivalent DAZLA gene. DAZ microdeletions were detected in 8.8% of patients. The three deleted patients have a 46, XY karyotype. Two of them were azoospermic and the other had an extreme oligo-asthenoteratozoospermia with a predominant abnormality: small round head spermatozoa (Y46). Our findings suggest that PCR-DGGE method, for detection of DAZ gene deletion, could be particularly useful as a first step in the diagnosis workup of nonobstructive azoospermia and severe oligozoospermia for three reasons. First, it is a simple and fast system; second, DAZ microdeletions are the most common Y deletions; and third, partial DAZ microdeletions and mosaicism may be recognized by PCR-DGGE while only deletions removing the whole DAZ gene cluster can be detected by STS-PCR [211]. Nevertheless, this procedure has limitations because other deletions of AZFa and AZFb may go undetected. Therefore, molecular investigation by multiplex PCR must be conducted in a second step according to European guidelines for the molecular diagnosis of Y chromosome microdeletions, particularly before ICSI procedures.

Chromosome Deletion↗
PubMed1997

Microdeletions of the Y chromosome and intracytoplasmic sperm injection: from gene to clinic.

Intracytoplasmic sperm injection (ICSI) is a successful treatment option for severe male infertility, although the aetiology of the disorder remains unclear in most cases. Recently, microdeletions in the AZF region of the Y chromosome have been detected in men with azoospermia or severe oligozoospermia. In this study we investigated the prevalence of microdeletions in the AZF region of the Y chromosome in a population of men undergoing ICSI, and looked for clinical characteristics of men with and without this deletion. Blood was drawn from 164 men, who were on the waiting list for ICSI treatment: 19 were azoospermic, 111 oligozoospermic and 34 normozoospermic (after previous total fertilization failure). A total of 100 men with proven fertility served as a control. Microdeletions in the AZFc region were present in seven of the 111 oligozoospermic men (6.3%). Compared with oligozoospermic men without microdeletions, men with microdeletions had a lower concentration of follicle stimulating hormone (FSH), a lower number of motile spermatozoa and a lower frequency of abnormal findings at andrological history or examination. No microdeletions were found in the azoospermic, normozoospermic and control groups. In conclusion, microdeletions in the AZFc region are relatively frequently found in men with severe unexplained oligozoospermia. In the ICSI era this finding has an important impact because this form of male infertility is now potentially hereditary. Therefore we recommend DNA screening (and genetic counselling) before ICSI, especially in men with normal FSH, severe oligozoospermia and no abnormal clinical andrological findings.

Case-Control Studies↗
PubMed2001

The prognostic role of the extent of Y microdeletion on spermatogenesis and maturity of Sertoli cells.

Substantial involvement of the Y chromosome in sexual development and spermatogenesis has been demonstrated. Over the last decade, varying extent of Y chromosome microdeletions have been identified among infertile patients with azoospermia or oligozoospermia. These microdeletions were clustered in three main regions named AZFa, AZFb, and AZFc. Analysis of the Y chromosome microdeletion was found to be of prognostic value in cases of infertility, both in terms of clinical management as well as for understanding the aetiology of the spermatogenesis impairment. However, the accumulated data are difficult to analyse, due to the variable extent of these deletions, the different sequence-tagged sites (STS) used to detect the microdeletions, and the non-uniformity of the histological terminology used by different investigators. This debate discusses the chances of finding testicular spermatozoa in men with a varying extent of Y chromosome microdeletions. The genotype and germ cell findings in men with AZFa microdeletions as well as those that include more than a single AZF region are reviewed, as is the effect of Y chromosome AZF microdeletions on the maturity of the Sertoli cells.

Cellular Senescence↗
PubMed2006

Y chromosome microdeletions in azoospermic patients with Klinefelter's syndrome.

AIM: To study the occurrence of Y chromosome microdeletions in azoospermic patients with Klinefelter's syndrome (KFS). METHODS: Blood and semen samples were collected from azoospermic patients with KFS (n = 14) and a control group of men of proven fertility (n = 13). Semen analysis was done according to World Health Organization (WHO) guidelines. Blood samples were processed for karyotyping, fluorescent in situ hybridization (FISH) and measurement of plasma follicle stimulating hormone (FSH) by radioimmunoassay. To determine Y chromosome microdeletions, polymerase chain reaction (PCR) of 16 sequence tagged sites (STS) and three genes (DFFRY, XKRY and RBM1Y) was performed on isolated genomic DNA. Testicular fine needle aspiration cytology (FNAC) was done in selected cases. RESULTS: Y chromosome microdeletions spanning the azoospermia factor (AZF)a and AZFb loci were found in four of the 14 azoospermic patients with KFS. Karyotype and FISH analysis revealed that, of the four cases showing Y chromosome microdeletion, three cases had a 47,XXY/46,XY chromosomal pattern and one case had a 46,XY/47,XXY/48,XXXY/48,XXYY chromosomal pattern. The testicular FNAC of one sample with Y chromosome microdeletion revealed Sertoli cell-only type of morphology. However, no Y chromosome microdeletions were observed in any of the 13 fertile men. All patients with KFS had elevated plasma FSH levels. CONCLUSION: Patients with KFS may harbor Y chromosome microdeletions and screening for these should be a part of their diagnostic work-up, particularly in those considering assisted reproductive techniques.

Adolescent↗
PubMed2002

Inhibin B: a marker for the functional state of the seminiferous epithelium in patients with azoospermia factor C microdeletions.

Testicular production of inhibin B is believed to be dependent on the presence of germ cells within the seminiferous tubules. However, this association has recently been questioned in patients with deletions of azoospermia factor (AZF) on the Y chromosome. We have addressed this problem in 442 unselected infertile/subfertile patients (excluding obstructive and iatrogenic forms) who were analyzed for Yq microdeletions. AZFc microdeletions were found in 16 patients (3.8% of the total infertile group, but 9% of the subgroup with azoospermia or severe oligozoospermia with sperm concentration <1 x 10(6)/ml). The reproductive hormone profiles in patients with AZFc microdeletions were analyzed and compared with those in infertile patients without microdeletions and those in fertile control individuals. The mean serum inhibin B concentration in the patients with AZFc microdeletions (39.5 +/- 36.0 pg/ml) was significantly lower than that in the group of infertile patients without microdeletions (134.6 +/- 88.5 pg/ml). However, no significant difference was found compared with that in a matched group of infertile patients with comparably low sperm counts (72.6 +/- 75.5 pg/ml). Bilateral testicular biopsies in the AZFc-deleted patients revealed a variable histological pattern suggestive of a progressive depletion of seminiferous epithelium. An association between testicular pathology and the reproductive hormone profile was found; the more severe forms had lower inhibin B and higher FSH levels. Importantly, if Sertoli cell-only tubules were prevalent in the biopsy, inhibin B was invariably undetectable. In patients with bilateral spermatocytic arrest, inhibin B remained within the normal range, which is consistent with a role of spermatocytes in the maintenance of inhibin B secretion. Our data support the view that, in contrast to recently published data, in patients with AZF microdeletions the serum concentration of inhibin B is dependent upon the functional interaction between Sertoli cells and spermatocytes and/or spermatids.

Adult↗
PubMed2007

Molecular and clinical characterization of Y chromosome microdeletions in infertile men: a 10-year experience in Italy.

CONTEXT: An explosive growth in Y chromosome long arm (Yq) microdeletion testing demand for male infertility occurred in the past few years. However, despite the progresses in the biology of this chromosome, a number of molecular and clinical concerns are not supported by definitive data. OBJECTIVE: The objective was to provide information on the type and prevalence of microdeletions in infertile males, indication for testing, genotype-phenotype correlation, sperm aneuploidies, and genetic counseling. DESIGN AND SETTING: We performed a prospective study from January 1996 to December 2005 in an academic clinic. PATIENTS: We studied 3073 consecutive infertile men, of which 625 were affected by nonobstructive azoospermia and 1372 were affected by severe oligozoospermia. Ninety-nine patients with microdeletions are described here. MAIN OUTCOME MEASURES: Yq microdeletions, seminal analysis, reproductive hormones, testicular cytology/histology, and sperm sex chromosomes aneuploidies were used as outcome measures. RESULTS: The prevalence of microdeletions was 3.2% in unselected infertile men, 8.3% in men with nonobstructive azoospermia, and 5.5% in men with severe oligozoospermia. Only 2 of 99 deletions were found in men with more than 2 million sperm/ml. No clinical data are useful to identify a priori patients with higher risk of Yq microdeletions. Most deletions are of the AZFc-b2/b4 subtype and are associated with variable spermatogenic phenotype, with sperm present in 72% of the cases. Complete AZFa and AZFb (P5/Proximal P1) deletions are associated with Sertoli cell-only syndrome and alterations in spermatocyte maturation, respectively, whereas partial deletions in these regions are associated with milder phenotype and frequent presence of sperm. Men with AZFc-b2/b4 deletions produce a higher percentage of sperm with nullisomy for the sex chromosomes and XY-disomy. CONCLUSIONS: This extensive clinical research expands the knowledge on genotype-phenotype relationships and confirms that the identification of Yq microdeletions has significant diagnostic and prognostic value, adding useful information for genetic counseling in these patients.

Adult↗
PubMedDate not supplied

Three-generation evaluation of Y-chromosome microdeletion.

Sperm cells can be retrieved directly from the testis (testicular sperm extraction [TESE] procedure) and used for intracytoplasmic sperm injection (ICSI), circumventing underlying spermatogenetic defects. Thus, it is important that added information be available on the genetic defects in men undergoing TESE for the ICSI procedure and on the transmission of genetic factors associated with infertility to the offspring. We report a three-generation genetic analysis of a family with a case of male factor infertility. The proband, previously diagnosed as infertile, was physically examined and laboratory tested for gonadotrophic hormones, semen analysis, karyotype and Y-chromosome microdeletion screening in the blood and testis. The Y-chromosome microdeletion screening was performed by multiplex polymerase chain reaction with 20 Y-chromosome sequenced, tagged sites located at the Y chromosome. A microdeletion including the AZF-c region was detected in the azoospermic patient. His father, four brothers, and three offspring born after ICSI also underwent Y-chromosome microdeletion screening. The genetic analysis of the male members of the patient's family did not reveal similar microdeletions. The newborn male was found to bear a Y-chromosome microdeletion similar to that of his father. The fertilization capacity of the proband testicular microdeleted spermatozoa by the ICSI procedure is described. The transfer of the genetic defect raises the possibility that the son will have the same fertility problem as his father.

Adult↗
PubMed2000

Frequency of microdeletions in the azoospermia factor region of the Y-chromosome of New Zealand men.

AIM: To determine the frequency of microdeletions in the azoospermic factor (AZF) genes on the Y-chromosome of New Zealand men attending the Fertility Centre. METHODS: World Health Organisation criteria were used to classify men as normospermic, oligozoospermic, severely oligozoospermic, and azoospermic. Microdeletions were detected from DNA of semen samples by the sequence-tagged site polymerase chain reaction. RESULTS: Microdeletions were detected in 20% (3/15) of azoospermic men, 4% (2/50) of severely oligozoospermic men, 3.2% (2/62) of oligozoospermic men, and 0.7% (1/141) normospermic men. One azoospermic man had multiple non-contiguous deletions. Overall, 5.5% of infertile men had at least one microdeletion in the long arm of the Y-chromosome. One severely oligozoospermic man and one oligozoospermic man had produced unassisted pregnancies. CONCLUSION: New Zealand men attending a Christchurch fertility centre have a similar frequency of microdeletions in the Y-chromosome to other populations. Azoospermic men have a higher frequency of microdeletions than men with less severe spermatogenic failure. Men with microdeletions can have reduced fertility, but are not necessarily sterile.

Case-Control Studies↗
PubMed2005

[Analysis of Yq microdeletions in idiopathic infertile males with azoospermia and oligospermia in Shaanxi Province].

OBJECTIVE: To evaluate the frequency of microdeletions in the long arm of Y chromosome of idiopathic infertile males with azoospermia and oligospermia in Shaanxi province in China and to investigate the relevance of sperm count to Y microdeletion frequencies. METHODS: According to the sequence of sequence-tagged sits (STS) AZFa, AZFb, AZFc and SRY, 4 of the azoospermic factor regions on Y chromosome long-term supplied by GenBank, 5 sets of primers were synthesized. The Y microdeletions in AZF regions were screened by polymerase chain reaction (PCR) in 64 idiopathic cases of azoospermia and oligospermia and 20 men of known fertility. RESULTS: No microdeletion was detected in the 20 normospermic subjects. Deletion of the AZFc/DAZ was detected in 11 individuals and one patient had both AZFb and AZFc deletion; no deletion of AZFa and SRY region was found. The frequency of Y microdeletions in the subgroups with different sperm count showed the highest value among azoospermic men (3 cases, 21.4%). The percentage progressively decreased with the deletion frequency (20.0%, 17.9% and 8.3%) in the subgroups with sperm counts of < 1 x 10(6)/ml, < (1-5) x 10(6)/ml and < (1 to approximately 10) x 10(6)/ml, respectively. CONCLUSION: Y chromosome microdeletions are specifically associated with severe spermatogenic failure. The rate of deletion involving AZF region of the Y-chromosome is higher in infertile men with azoospermia and oligospermia. PCR amplification of AZF locus is useful for the diagnosis of microdeletions in the Y-chromosome.

Adult↗
PubMed2005

Congenital heart defects and chromosomal anomalies including 22q11 microdeletion (CATCH 22).

OBJECTIVE: To analyze the frequency of chromosomal anomalies or 22q11 microdeletion in patients with congenital heart defects and other congenital anomalies; to describe the clinical phenotype of children with the 22q11 microdeletion and with chromosomal anomalies; to evaluate patients' clinical evolution; and to provide genetic counseling for families. METHODS: The study included 46 patients with congenital heart defects and other anomalies and patients with a phenotype consistent with 22q11 microdeletion observed between 1999 and 2001. Confirmation of the heart defect was accomplished through echocardiography, magnetic resonance angiography or cardiac catheterization. Karyotyping with high resolution banding and detection of 22q11 microdeletion with FISH techniques were performed. We excluded patients with trisomy 21, 13 and 18, 45,X and deletion of 7q11.23. Patients with 22q11 microdeletion underwent immunology studies and evaluation of parathyroid function. Clinical evolution was evaluated. Chromosome and FISH studies were performed on parents of affected children (25 couples). RESULTS: Forty-six children were included, of whom twelve (26.1%) had chromosomal anomalies (group A), fourteen (30.4%) had 22q11 microdeletion (group B) and the remaining twenty (43.5%) had normal karyotype and negative FISH studies (group C). In group A septal heart defects predominated. This group had significant morbidity, with surgical correction in three patients, early development of pulmonary hypertension, failure to thrive and serious neurological problems. Two patients died. In group B conotruncal heart defects (7/14) and ventricular septal defects (5/14, two associated with cervical aortic arch) predominated. The most significant morbidity was related to cardiac pathology, with surgical correction in seven cases (50%). Immune function defects and parathyroid function problems were mild, requiring no therapeutic measures. One patient died. CONCLUSION: In the presence of heart defects associated with other congenital anomalies, karyotyping is mandatory and if clinical features are compatible, 22q11 microdeletion should be specifically sought with FISH techniques. Detection of chromosomal anomalies has a significant impact on prognosis and follow-up of patients, as well as on genetic counseling of families.

Child, Preschool↗