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PubMed1999

Microdeletions within the azoospermia factor subregions of the Y chromosome in patients with idiopathic azoospermia.

OBJECTIVE: To examine the patterns of submicroscopic DNA deletions in the AZF (AZoospermia Factor) subregions of the Y chromosome in patients with idiopathic azoospermia. DESIGN: Controlled clinical study. SETTING: University-based infertility clinic. PATIENT(S): Infertile men (n = 40) with nonobstructive, idiopathic azoospermia. The control group consisted of proven fathers (n = 14) and healthy women (n = 4). INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): Semen analysis; polymerase chain reaction amplification of the 37 loci spanning the AZFa, AZFb, and AZFc subregions of the Y chromosome; serum FSH, LH, and testosterone levels; and testicular histologic analysis. RESULT(S): Testicular histologic analysis of the subjects revealed Sertoli cell-only syndrome (n = 36) and spermatogenic arrest (n = 4). Microdeletions of the Y chromosome were found in eight (20%) of the patients with azoospermia. All eight affected patients had interstitial microdeletions within the AZFc subregion. Patients with Sertoli cell-only syndrome had additional microdeletions in regions distal to DAZ (Deleted in Azoospermia), although DAZ deletion was observed in seven of the eight affected patients. In five patients, microdeletions were found in the AZFb region containing RBM (RNA Binding Motif). CONCLUSION(S): Our results add to the evidence supporting the current suggestion that there is a cause-and-effect relation between Yq11 microdeletions in the AZF region and azoospermia.

Adult↗
PubMedDate not supplied

[Molecular detection of Y chromosome microdeletions: a new approach based on the denaturing gradient gel electrophoresis].

Ten percent of couples trying for a child fail to conceive. In approximately 50% of cases, infertility is due to the inability of the male partner to produce spermatozoa in sufficient numbers to effect conception. Over the past 5 years, molecular studies have suggested that interstitial microdeletions in Yq11 represent an etiological factor for male infertility. Y-microdeletions have been detected in 12% of non-obstructive azoospermia and 6% of severe oligozoospermia. In general, microdeletions were detected by separate multiplex-polymerase chain reaction (PCR) reactions using primer pairs for single tagged sites (STSs) of all three azoospermia factor (AZF) regions (AZFa, AZFb and AZFc). This review describes the molecular methods and laboratory guidelines for molecular diagnosis of Y-chromosomal microdeletions. The diagnostics of Y-chromosomal microdeletions should be performed in two steps: in any case, the routine diagnostic should include six STS loci, two STS loci localised in each AZF region, and once a deletion is detected, the analysis can be extended to STS loci known to cross the proximal and the distal borderlines of each AZF region. Other molecular techniques such as DGGE, Southern blot should be performed to detect partial deletions of gene copies or mosaicism. These different molecular approaches should allow explaining 10% of male infertility, to evaluate the risk to pass the defect onto their male offspring (by intracytoplasmic sperm injection) and improve the genetic counselling of couples undergoing micromanipulative assisted reproduction.

Blotting, Southern↗
PubMed2001

Study of microdeletions in the Y chromosome of infertile men with idiopathic oligo- or azoospermia.

PURPOSE: To determine the relationships between idiopathic oligo- or azoospermia and microdeletions of the Y chromosome. METHODS: Eighteen Y-linked sequence-tagged sites (STSs) in AZF (Azoospermia Factor) region were screened by means of multiplex PCR (Polymerase Chain Reaction) in 50 idiopathic infertile men, including 16 patients with azoospermia, 13 severe oligospermia, and 21 oligospermia. RESULTS: Microdeletions in the genomic DNA were observed in 8 of 50 cases, 3 with azoospermia, I severe oligospermia, and 4 oligospermia. Total deletion rate was 16.0% (8/50). The deletion regions were concentrated on AZFd and AZFc. CONCLUSIONS: Microdeletions of the Y chromosome are an important cause for idiopathic oligo- or azoospermia. Multiplex PCR is a useful technique for detecting the microdeletions. To avoid transmission to their offspring, patients with idiopathic oligo- or azoospermia should be screened for microdeletions of the Y chromosome before ICSI treatment for infertility.

Adult↗
PubMed1999

Screening for microdeletions on the long arm of chromosome Y in 53 infertile men.

About 30% of couple infertilities are of male origin. They appear in some cases de novo and are considered idiopathic. The aim of our work was to evaluate, in these cases, the prevalence of microdeletions of the long arm of chromosome Y, within the AZF a, b and c regions using molecular biology techniques. Men with azoospermia or oligozoospermia resulting from hereditary, endocrine or obstructive causes, or with a constitutional cytogenetic abnormality were excluded. Fifty-three infertile men with azoospermia or oligozoospermia, as determined by a spermiogram, were studied. Of these, 34 were idiopathic and 7 exhibited a past history of genital infection or biological abnormalities, suggesting partial obstruction of the genito-urinary tract. A further 8 men had a varicocele and 11 cases with a history of cryptorchidism were also studied. Peripheral blood DNA was extracted from each patient, then amplified by multiplex PCR with STS genomic markers from the three Y chromosome AZF zones. PCR products were then analysed on agarose gels. In view of the difficulty of confirming the absence of a signal in molecular biology, each case suspected of having a deletion was checked by multiplex PCR through coamplification with the SRY marker. Five men with microdeletions of the long arm of the Y chromosome were diagnosed among the 53 patients. All of them included the AZFc zone and the intragenic DAZ gene markers. Furthermore, a larger Y chromosome deletion encompassing the 3 AZF zones was diagnosed, and confirmed by cytogenetic analysis. All Y chromosome microdeletions were observed in the 34 truly idiopathic azoospermia/oligozoospermia cases, corresponding to a proportion of 14.7% (or 9.4% considering the whole population of 53 infertile men). The relatively high proportion of microdeletions found in our series suggests the need for strict patient selection to avoid unnecessary screening for long arm Y chromosome microdeletions.

Adult↗
PubMedDate not supplied

Screening of Y chromosome microdeletions in Tunisian infertile men.

The aim of this study was to establish the prevalence of Y chromosomal microdeletions in infertile Tunisian men. Three groups of infertile men, 65 normospermic, 53 oligozoospermic and 45 azoospermic, were tested for Yq microdeletions detection by multiplex polymerase chain reaction (PCR) using specific Y chromosome AZF regions tagged site markers (STS). One group of 13 healthy men was used as the control group. Six STS were tested (2 in each AZF region). The general prevalence of AZF microdeletions was 16%; in azoospermia and severe oligospermia groups, it was higher (29% and 30.5%, respectively). Significant differences were found with moderate oligospermic and normospermic groups (p < 0,05). AZFc microdeletions were the most frequent, and 55% of AZFc deleted patients were oligospermic. No deletions were detected in the control group. These results add to the growing literature data, showing that microdeletions of the Y chromosome is an important cause of severe spermatogenetic defect and confirm that deletion in AZFc region is the most common and is compatible with residual spermatogenesis.

Chromosome Deletion↗
PubMed2003

Elevated risk for MPNST in NF1 microdeletion patients.

An NF1 microdeletion is the single most commonly reported mutation in individuals with neurofibromatosis type 1 (NF1). Individuals with an NF1 microdeletion have, as a group, more neurofibromas at a younger age than the group of all individuals with NF1. We report that NF1 microdeletion individuals additionally have a substantially higher lifetime risk for the development of malignant peripheral nerve sheath tumors than individuals with NF1 who do not have an NF1 microdeletion. This should be taken into account in the medical follow-up of individuals with an NF1 microdeletion.

Adolescent↗
PubMed1997

Simultaneous, multilocus FISH analysis for detection of microdeletions in the diagnostic evaluation of developmental delay and mental retardation.

Many microdeletion and contiguous gene-deletion syndromes include mental retardation as a clinical feature. We have developed MultiFISH, a FISH assay using several probes to simultaneously screen for multiple microdeletion syndromes in patients who present with unexplained devleopmental delay and/or mental retardation. This screening tool can be used to determine whether a particular microdeletion syndrome is involved in the etiology of these clinical phenotypes. In this pilot study we combined probes for the commonly deleted regions of Prader-Willi, Angelman, Williams, Smith-Magenis, and DiGeorge/velocardiofacial syndromes in a single hybridization. The probes were differentially labeled, allowing multicolor detection, and 200 individual samples were screened in a blinded fashion. For all patients found by MultiFISH to have deletions, the deletions were originally identified and/or later confirmed by use of single-probe FISH analysis in our diagnostic cytogenetics laboratory. One patient, who was referred for developmental delay and was shown to have a normal G-banded karyotype, was identified by MultiFISH as having a micro-deletion at the DiGeorge/velocardiofacial commonly deleted region. Forty-six of the 200 total samples were tested for microdeletions by use of single FISH probes in the diagnostic laboratory. Ten of these cases were found to have deletions, and all deletions were subsequently detected by use of MultiFISH screen performed in a blinded fashion. Additionally, for all 200 patients tested by use of MultiFISH, no false-positive deletion results were observed. We demonstrate the ability of this technique to scan for and to identify microdeletions in a proportion of patients whose routine karyotype appears normal yet who are mentally retarded and/or developmentally delayed.

Child↗
PubMed1998

Does intracytoplasmic sperm injection lead to a rise in the frequency of microdeletions in the AZFc region of the Y chromosome in future generations?

Microdeletions in the AZFc region of the Y chromosome are found in oligo- and azoospermic men. These mutations were genetically lethal before the intracytoplasmic sperm injection (ICSI) era but they can nowadays be transmitted to next generations via ICSI. We have tried to answer the question, 'Does ICSI lead to a significant rise in the frequency of these microdeletions in future generations?', by developing a mathematical model for Y-linked mutations with two variables (fitness and mutation frequency). To illustrate this model we have made estimates according to three imaginary scenarios. Using the assumptions described, the model predicted that the frequency of microdeletions in the AZFc region would increase in each generation until a plateau was reached. The higher the fitness, the higher the plateau and the later the plateau would be reached. Taking realistic estimates for fitness (0.5) and spontaneous mutation frequency (0.0001), the maximum increase in men with microdeletions would be twofold. This maximum would be already reached after five generations. However, if the fitness of these men were improved and approached 1.0, the mechanism of selection would disappear and finally all men would have the deletion in the AZFc region. Because of the assumptions in these scenarios, these estimates have limitations. The model presented shows that the rise in the frequency of men with microdeletions in the AZFc region in future generations would be limited as long as the fitness of these men remained limited.

Chromosome Deletion↗
PubMed1999

Screening for microdeletions of Y chromosome genes in patients undergoing intracytoplasmic sperm injection.

The potential of assisted reproduction techniques to transmit genetic defects causing male infertility raises questions concerning the need for a systematic genetic screen and counselling. Deletions of the long arm of the Y chromosome are frequently associated with a failure of spermatogenesis. The search for Y specific sequences and for the gene families RNA binding motif (RBM) and deleted in azoospermia (DAZ) have been introduced in many laboratories. The incidence of Y microdeletions varies widely between studies, from 1-55%. These differences are mainly related to study design. The highest incidence of microdeletions has been reported in well selected idiopathic azoospermic patients. Since microdeletions have been reported also in non-idiopathic patients, it is important to define what is the deletion frequency in unselected patients. We report Y chromosome microdeletion screening in 134 unselected patients undergoing intracytoplasmic sperm injection (ICSI). In the first part of the study we tested six Y chromosome markers. We found three patients with microdeletions (2.2%). Subdivision of the study population revealed a deletion incidence of 4.7% in azoospermic/cryptozoospermic patients; an incidence of 7% in idiopathic patients and an incidence of 16% in idiopathic azoospermic/cryptozoospermic patients. The second part of the study consisted of a screen for the presence of the Y chromosome genes, DBY, CDY, XKRY, eIF-1A, DAZ and BPY2. No additional gene-specific deletions were found. Further data on gene specific screening are needed especially for selected idiopathic patients.

Base Sequence↗
PubMed1997

Combined cytogenetic and Y chromosome microdeletion screening in males undergoing intracytoplasmic sperm injection.

We evaluated the frequency of chromosomal aberrations and microdeletions of the Y chromosome in a sample of 204 patients included in an intracytoplasmic sperm injection (ICSI) programme. The prevalence of Y chromosome deletions in males with severely or only moderately reduced sparm counts is mainly unknown, so that patients were chosen with sperm counts ranging from mild oligozoospermia to azoospermia. While six out of 158 (3.8%) patients showed constitutional chromosomal aberrations, only two out of 204 (0.98%) patients were diagnosed with a microdeletion of Yq11. One had a terminal deletion in subinterval 6 of Yq11.23 which included the DAZ gene and a corresponding sperm count < 0.1 x 10(6) spermatozoa/ml. The second patient had an isolated deletion of marker Y6PH54c, a more proximal site in subinterval 5 on Yq11.23, but repeatedly showed sperm counts of 3-8 x 10(8) spermatozoa/ml. Thus, of the 158 patients who underwent a combined cytogenetic and Y-microdeletion screening, eight patients (5.1%) showed chromosomal abnormalities, either at the cytogenatic (n = 6) or the molecular level (n = 2). In conclusion, although rare in number, microdeletions of the Y chromosome can also be observed in patients with moderately reduced sperm counts. A more proximal site of the deletion breakpoint does not necessarily imply a more severe impairment of spermatogenesis than a distal deletion site. In our sample, the overall frequency of constitutional chromosomal aberrations exceeded the incidence of microdeletions of the Y chromosome even in patients with idiopathic azoo- or severe oligozoospermia.

Chromosome Deletion↗
PubMed1998

Y chromosome microdeletions, in azoospermic or near-azoospermic subjects, are located in the AZFc (DAZ) subregion.

Submicroscopic deletions of the Y chromosome and polymorphisms of the androgen receptor (AR) gene in the X chromosome have been observed in men with defective spermatogenesis. To further define the subregions/genes in the Y chromosome causing male infertility and its relationship to polymorphisms of the AR polyglutamine tract, we screened the genomic DNA of 202 subfertile males and 101 healthy fertile controls of predominantly Chinese ethnic origin. Y microdeletions were examined with 16 sequence-tagged site (STS) probes, including the RBM and DAZ genes, spanning the AZFb and AZFc subregions of Yq11, and related to the size of trinucleotide repeat encoding the AR polyglutamine tract. Y microdeletions were detected and confirmed in three out of 44 (6.8%) of azoospermic and three out of 86 (3.5%) severely oligozoospermic patients. No deletions were detected in any of the patients with sperm counts of >0.5 x 10(6)/ml, nor in any of the 101 fertile controls. All six affected patients had almost contiguous Y microdeletions spanning the entire AZFc region including the DAZ gene. The AZFb region, containing the RBM1 gene, was intact in five of the six subjects. Y deletions were not found in those with long AR polyglutamine tracts. Our study, the first in a Chinese population, suggest a cause and effect relationship between Y microdeletions in the AZFc region (possibly DAZ), and azoospermia or near-azoospermia. Y microdeletions and long AR polyglutamine tracts appear to be independent contributors to male infertility.

Adult↗
PubMed2004

EAA/EMQN best practice guidelines for molecular diagnosis of y-chromosomal microdeletions. State of the art 2004.

Microdeletions of the Y chromosome are the second most frequent genetic cause of spermatogenetic failure in infertile men after the Klinefelter syndrome. The molecular diagnosis of Y-chromosomal microdeletions is routinely performed in the workup of male infertility in men with azoospermia or severe oligozoospermia. Since 1999, the European Academy of Andrology (EAA) and the European Molecular Genetics Quality Network (EMQN) support the improvement of the quality of the diagnostic assays by publication of the laboratory guidelines for molecular diagnosis of Y-chromosomal microdeletions and by offering external quality assessment trials. The present revision of the 1999 laboratory guidelines summarizes the results of a 'Best Practice Meeting' held in Florence (Italy) in October 2003. The basic protocol for microdeletion screening suggested in the 1999 guidelines proved to be very accurate, sensitive and robust. In the light of the recent advance in the knowledge of the Y chromosome sequence and of the mechanism of microdeletion it was agreed that the basic 1999 protocol, based on two multiplex polymerase chain reactions each covering the three AZF regions, is still fully valid and appropriate for accurate diagnosis.

Chromosome Aberrations↗
PubMedDate not supplied

Screening for microdeletions in human Y chromosome--AZF candidate genes and male infertility.

About 30% of couple infertilities are of male origin, some of them caused by genetic abnormalities of the Y chromosome. Deletions in AZF region can cause severe spermatogenic defects ranging from non-obstructive azoospermia to oligospermia. The intracytoplasmatic sperm injection technique (ICSI) is rapidly becoming a versatile procedure for human assisted reproduction in case of male infertility. The use of ICSI allows Y chromosome defects to be passed from father. The goal of our study is to evaluate the frequency of microdeletions in the long arm of Y chromosome, within the AZF regions, in these cases of infertilities, using molecular genetics techniques. Thirty infertile men with azoospermia or oligozoospermia, determined by spermogram, were studied after exclusion of patients with endocrine or obstructive causes of infertility. Peripheral blood DNA was extracted from each patient, then amplified by multiplex PCR with STS genomic markers from the Y chromosome AZF zones. Each case was checked by multiplex PCR through coamplification with the SRY marker. Three men with microdeletions of the long arm of the Y chromosome were diagnosed among the 30 patients, corresponding to a proportion of 10%. The relatively high proportion of microdeletions found in our population suggest the need for strict patient selection to avoid unnecessary screening for long arm Y chromosome microdeletions. The molecular diagnostics was performed according to the current European Academy of Andrology laboratory guidelines for molecular diagnosis of Y chromosomal microdeletions.

Adult↗
PubMed2007

Frequency of Y chromosome microdeletions and chromosomal abnormalities in infertile Thai men with oligozoospermia and azoospermia.

AIM: To investigate the possible causes of oligozoospermia and azoospermia in infertile Thai men, and to find the frequencies of Y chromosome microdeletions and cytogenetic abnormalities in this group. METHODS: From June 2003 to November 2005, 50 azoospermic and 80 oligozoospermic men were enrolled in the study. A detailed history was taken for each man, followed by general and genital examinations. Y chromosome microdeletions were detected by multiplex polymerase chain reaction (PCR) using 11 gene-specific primers that covered all three regions of the azoospermic factor (AZFa, AZFb and AZFc). Fifty men with normal semen analysis were also studied. Karyotyping was done with the standard G- and Q-banding. Serum concentrations of follicle stimulating hormone (FSH), luteinizing hormone (LH), prolactin (PRL) and testosterone were measured by electrochemiluminescence immunoassays (ECLIA). RESULTS: Azoospermia and oligozoospermia could be explained by previous orchitis in 22.3%, former bilateral cryptorchidism in 19.2%, abnormal karyotypes in 4.6% and Y chromosome microdeletions in 3.8% of the subjects. The most frequent deletions were in the AZFc region (50%), followed by AZFb (33%) and AZFbc (17%). No significant difference was detected in hormonal profiles of infertile men, with or without microdeletions. CONCLUSION: The frequencies of Y chromosome microdeletions and cytogenetic abnormalities in oligozoospermic and azoospermic Thai men are comparable with similarly infertile men from other Asian and Western countries.

Azoospermia↗
PubMed2006

Y-chromosome haplogroups and susceptibility to azoospermia factor c microdeletion in an Italian population.

BACKGROUND: A limited number of studies aimed at investigating the possible association of Y-chromosome haplogroups with microdeletions of the azoospermia factors (AZFs) or with particular infertile phenotypes, but definitive conclusions have not been attained. The main confounding elements in these association studies are the small sample sizes and the lack of homogeneity in the geographical origin of studied populations, affecting, respectively, the statistical power and the haplogroup distribution. MATERIALS AND METHODS: To assess whether some Y-chromosome haplogroups are predisposing to, or protecting against, azoospermia factor c (AZFc; b2/b4) deletions, 31 north Italian patients carrying the AZFc b2/b4 microdeletion were characterised for 8 Y-chromosome haplogroups, and compared with the haplogroup frequency shown by a north Italian population without the microdeletion (n = 93). RESULTS AND DISCUSSION: A significant difference was observed between the two populations, patients with microdeletions showing a higher frequency of the E haplogroup (29.3% vs 9.7%, p<0.01). The geographical homogeneity of the microdeleted samples and of the control population, controlled at microgeographical level, allows the possibility that the geographical structure of the Y genetic variability has affected our results to be excluded. CONCLUSION: Thus, it is concluded that in the north Italian population Y-chromosome background affects the occurrence of AZFc b2/b4 deletions.

Adult↗
PubMed2006

Y chromosome microdeletions in infertile men with idiopathic oligo- or azoospermia.

About 30-40% of male infertility is due to unknown reasons. Genetic contributions to the disruption of spermatogenesis are suggested and amongst the genetic factors studied, Y chromosome microdeletions represent the most common one. Screening for microdeletions in AZFa, b and c region of Y chromosome showed a big variation among different studies. The purpose of this study was to investigate the prevalence of such deletions in Saudi men. A total of 257 patients with idiopathic oligo- or azoospermia were screened for Y chromosome microdeletions by 19 markers in AZF region. Ten (3.9%) patients had chromosomal rearrangements, six of them showed sex chromosome abnormalities and four patients had apparently balanced autosomal rearrangements. Eight of the remaining 247 patients (3.2%) with a normal karyotype and no known causes of impaired spermatogenesis had Y chromosome microdeletions. Among these, six patients had deletions in AZFc region, one case had a deletion in AZFb and another had both AZFa and AZFc deletions.In conclusion, our study shows that Y chromosome microdeletions are low in our population. We also report for the first time a case with unique point deletions of AZFa and AZFc regions. The lower frequency of deletions in our study suggest that other genetic, epigenetic, nutritional and local factors may be responsible for idiopathic oligo- or azoospermia in the Saudi population.

Journal Article↗
PubMedDate not supplied

[Microdeletions of the Y chromosome in cryptorchidism and in idiopathic male infertility].

We investigated the possible role of Y chromosome microdeletions in regions previously shown to be important for male germ cell development in unilateral ex-cryptorchid subjects manifesting important bilateral testiculopathy, in order to clarify whether cryptorchidism could be the expression of an intrinsic congenital testicular abnormality. Microdeletion analysis of the Y chromosome long arm was performed by polymerase chain reaction and confirmed by Southern blot in 40 selected unilateral ex-cryptorchid patients with azoospermia or severe oligozoospermia sustained by severe bilateral testiculopathy (Sertoli cell-only syndrome and severe hypospermatogenesis, respectively), 20 unilateral ex-cryptorchid men with moderate oligozoospermia and normal function of the descended testis, 110 patients affected by severe idiopathic primary testiculopathies, 20 patients affected by moderate idiopathic testiculopathy and, as controls, 50 patients affected by known causes of testiculopathy and 50 fertile controls. Eleven out of the 40 (27.5%) unilateral ex-cryptorchid patients affected by bilateral testiculopathy and 28 out of 110 (25.4%) patients affected by severe idiopathic primary testiculopathy showed microdeletions in the Y chromosome long arm, while all other subjects were normal. Male relatives of patients with deletions were also normal. Microdeletions were distributed in different regions of the Y chromosome long arm, including known regions involved in spermatogenesis (DAZ and RBM genes, AZFa, b and c regions) and other still poorly defined loci. No difference in localization of deletions was evident between ex-cryptorchid and idiopathic patients. Microdeletions in the Y chromosome may be responsible for bilateral severe testicular damage: the clinical consequence, other than idiopathic azoospermia and severe oligozoospermia, may also be unilateral cryptorchidism, probably due to altered testicular responses to mechanisms regulating testicular descent.

Biopsy, Needle↗
PubMed2001

[Clinical heterogeneity of the chromosome 22q11 microdeletion syndrome].

BACKGROUND: DiGeorge anomaly, velocardiofacial syndrome and conotruncal anomaly face syndrome are part of a group of congenital malformations of the chromosome 22q11 microdeletion syndrome, since they share certain phenotypic features as well as a common genetic abnormality. The malformations include mild facial dysmorphic features, conotruncal heart defects, thymic and parathyroid hypoplasia or aplasia and cleft palate. AIM: To describe the initial clinical presentation of children with clinical and molecular diagnosis of 22q11 microdeletion. PATIENTS AND METHODS: Ten children (seven male) with the phenotypic features of 22q11 microdeletion syndrome are reported. Microdeletion was detected in peripheral lymphocytes by fluorescent in situ hybridisation (FISH) with the TUPLE-1 DNA probe. RESULTS: Two children had abnormal karyotypes, one of them had a visible deletion and another child had an unbalanced translocation inherited from his mother who had a balanced translocation between chromosomes 14 and 22. Two of the 10 patients had an anterior laryngeal web, a malformation infrequently described in this syndrome. Five patients had the diagnosis of DiGeorge anomaly, had a more serious clinical presentation and a higher early mortality. CONCLUSIONS: The high frequency of the 22q11 microdeletion syndrome, estimated at 1:5.000 newborns, and its variable presentations requires a high level of awareness for its early diagnosis and appropriate management of associated complications.

Child↗