AZFa, AZFb, AZFc and gr/gr Y-chromosome microdeletions in azoospermic and severe oligozoospermic patients, analyzed from a neural network perspective.

AIM: Analysis of male infertility by molecular methods has increased since recognition of genetic risk factors. The AZFa, AZFb, AZFc, and gr/gr regions on the Y-chromosome can cause male infertility. The aim of this study was to determine the prevalence of Y-chromosome microdeletions in these regions in infertile Mexican patients. MATERIAL AND METHODS: We recruited 57 infertile patients with abnormal sperm count (26 azoospermic and 31 oligozoospermic) and 55 individuals with normal sperm count. Analysis of the regions of interest was performed by PCR. RESULTS: 15.8% of infertile patients presented Y-chromosome microdeletions, whereas no deletions were found in the control group. Deletions were observed in all the analyzed regions except in AZFa. Additionally, the neural network model revealed a mild genotype-phenotype correlation between deletion of the sY1191, sY1291 and sY254 markers with oligozoospermia, azoospermia and cryptozoospermia, respectively. CONCLUSIONS: Our data show that AZFb, AZFc, and gr/gr microdeletions are significantly associated with infertility in Mexican population. In addition, the neural network model revealed a discrete genotype-phenotype correlation between specific deletions and a particular abnormality. Our results reinforce the importance of the analysis of AZF regions as part of the clinical approach of infertile men.

OBJETIVO: La utilización de técnicas moleculares para estudiar la infertilidad masculina se ha incrementado desde el reconocimiento de factores genéticos. Las regiones AZFa, AZFb, AZFc, y gr/gr del cromosoma Y son causa de infertilidad masculina. El objetvo de este estudio fue determinar la prevalencia de microdeleciones en estas regiones en pacientes infértiles Mexicanos. MATERIAL Y MÉTODOS: Reclutamos 57 pacientes infértiles con cuentas espermáticas anormales (26 con azoospermia y 31 con oligozoospermia) y 55 individuos con cuentas espermáticas normales. El análisis de las regiones se realizó mediante PCR. RESULTADOS: 15.8% de los pacientes infértiles presentó microdeleciones, no se encontraron microdeleciones en el grupo control. Las microdeleciones fueron observadas en todas las regiones excepto en AZFa. Adicionalmente, el modelo de red neuronal reveló una leve correlación genotipo-fenotipo entre microdeleciones de los marcadores sY1191, Sy1291 y sY254 con oligozoospermia, azoospermia y criptozoospermia, respectivamente. CONCLUSIONES: Nuestros datos muestran que las microdeleciones en AZFb, AZFc, y gr/gr se asocian significativamente con infertilidad en la población Mexicana. Además, el modelo de red neuronal reveló una discreta correlación genotipo-genotipo entre microdeleciones específicas con una anormalidad en particular. Nuestros resultados refuerzan la importancia del análisis de las regiones AZF en el abordaje de la infertilidad masculina.

Cardiovascular findings in Williams-Beuren Syndrome: Experience of a single center with 127 cases.

Williams-Beuren syndrome (WBS) is a rare, microdeletion syndrome characterized by facial dysmorphisms, intellectual disability, a friendly personality, cardiovascular and other abnormalities. Cardiovascular defects (CVD) are among the most prevalent characteristics in WBS, being supravalvular aortic stenosis (SVAS) the most frequent, followed by peripheral pulmonary stenosis (PPS). A comprehensive retrospective review of medical records of 127 patients with molecular diagnosis of WBS, in a period of 20 years, was done to evaluate the incidence, the natural history of cardiovascular disease, and the need for surgical intervention, including heart transplantation (HT). A total of 94/127 patients presented with CVD. Of these 94 patients, 50% presented with SVAS and 22.3% needed heart surgery and/or cardiac catheterization including one that required HT due to severe SVAS-related heart failure at 19 years of age. The patient died in the postoperative period due to infectious complications. Cardiovascular problems are the major cause of sudden death in patients with WBS, who have a significantly higher mortality risk associated with surgical interventions. There is a higher risk for anesthesia-related adverse events and for major adverse cardiac events following surgery. End-stage heart failure due to myocardial ischemia has been described in WBS patients and it is important to consider that HT can become their only viable option. To our knowledge, the case mentioned here is the first HT reported in an adolescent with WBS. HT can be a viable therapeutic option in WBS patients with adequate evaluation, planning, and a multidisciplinary team to provide the required perioperative care and follow-up.

Genómica de los trastornos del desarrollo neurológico / Genomics of neurodevelopmental disorders

Introduction: Neurodevelopmental disorders (NDD) are featured by a delay in the acquisition of motor functions, cognitive abilities and speech, or combined deficits in these areas with the onset before the age of 5 years. Genetic causes account for approximately a half of all NDD cases. Objective: to describe alterations of the genome implied in neurodevelopmental disorders and some aspects of their genetic counseling. Methods: Bibliographic search in Medline, Pubmed, Scielo, LILACS and Cochrane, emphasizing in the last five years, the relationship between the various genetic factors that may be involved in neurodevelopmental disorders. Results: Multiple genetic factors are involved in neurodevelopmental disorders, from gross ones such as chromosomal aneuploidies to more subtle ones such as variations in the number of copies in the genome. Special emphasis is placed on microdeletion-micro duplication syndromes as a relatively frequent cause of NDDs and their probable mechanisms of formation are explained. Final Considerations: Genetic aberrations are found in at least 30-50 percent of children with NDD. Conventional karyotyping allows the detection of chromosomal aberrations encompassing more than 5-7 Mb, which represent 5-10 percent of causative genome rearrangements in NDD. Molecular karyotyping (e.g. SNP array/array CGH) can significantly improve the yield in patients with NDD and congenital malformations(AU)

Introducción: Los trastornos del neurodesarrollo están caracterizados por retardo en la adquisición de las funciones motoras, habilidades cognitivas para el habla o el déficit combinado en estas áreas; se presenta en niños menores de 5 años de edad. Las causas genéticas están implicadas en más de la mitad de los pacientes con estos trastornos Objetivo: Examinar las alteraciones del genoma implicados en los trastornos del neurodesarrollo y algunos aspectos de su asesoramiento genético. Métodos: Búsqueda bibliográfica en Medline, Pubmed, Scielo, LILACS y Cochrane con énfasis en los últimos cinco años, acerca de la relación entre los variados factores genéticos que pueden estar involucrados en los trastornos del neurodesarrollo. Resultados: Los factores genéticos involucrados pueden ser groseros como las aneuploidías cromosómicas hasta los más sutiles como las variaciones en el número de copias en el genoma. Se describen los síndromes de microdeleción-micro duplicación como una causa relativamente frecuente de los trastornos del neurodesarrollo y se explican sus probables mecanismos de formación. Se relacionan las aneuploidías cromosómicas y las variaciones en el número de copia como causas de estos trastornos. Consideraciones finales . Las aberraciones genéticas se encuentran en 30-50 por ciento de los niños con trastornos del neurodesarrollo. El cariotipo convencional permite la detección de aberraciones cromosómicas que abarcan más de 5-7 Mb, lo que representa 5-10 por ciento de los reordenamientos genómicos causales en estos trastornos. El cariotipo molecular (por ejemplo, una matriz de SNP/ CGH de matriz) puede mejorar significativamente la certeza del diagnóstico en pacientes con trastornos del neurodesarrollo y malformaciones congénitas(AU)

High frequency of Y chromosome microdeletions in male infertility patients with 45,X/46, XY mosaicism

The mosaic 45,X/46,XY karyotype is a common sex chromosomal abnormality in infertile men. Males with this mosaic karyotype can benefit from assisted reproductive therapies, but the transmitted abnormalities contain 45,X aneuploidy as well as Y chromosome microdeletions. The aim of this study was to investigate the clinical and genetic characteristics of infertile men diagnosed with 45,X/46,XY mosaicism in China. Of the 734 infertile men found to carry chromosomal abnormalities, 14 patients were carriers of 45,X/46,XY mosaicism or its variants, giving a prevalence of 0.27% (14/5269) and accounting for 1.91% (14/734) of patients with a chromosomal abnormality. There were ten cases (71.43%, 10/14) of 45,X mosaicism exhibiting AZF microdeletions. Case 1 and Case 4 had AZFc deletions, and the other eight cases had AZFb+c deletions. A high frequency of Y chromosome microdeletions were detected in male patients with 45,X/46,XY mosaicism. Preimplantation genetic diagnosis should be offered to men having intracytoplasmic sperm injection for hypospermatogenesis caused by 45,X/46,XY mosaicism, to avoid the risk of transfering AZF microdeletions in addition to X monosomy in male offspring.

The Role of Co-Deleted Genes in Neurofibromatosis Type 1 Microdeletions: An Evolutive Approach.

Neurofibromatosis type 1 (NF1) is a cancer predisposition syndrome that results from dominant loss-of-function mutations mainly in the NF1 gene. Large rearrangements are present in 5-10% of affected patients, generally encompass NF1 neighboring genes, and are correlated with a more severe NF1 phenotype. Evident genotype-phenotype correlations and the importance of the co-deleted genes are difficult to establish. In our study we employed an evolutionary approach to provide further insights into the understanding of the fundamental function of genes that are co-deleted in subjects with NF1 microdeletions. Our goal was to access the ortholog and paralog relationship of these genes in primates and verify if purifying or positive selection are acting on these genes. Fourteen genes were analyzed in twelve mammalian species. Of these, four and ten genes showed positive selection and purifying selection, respectively. The protein, RNF135, showed three sites under positive selection at the RING finger domain, which may have been selected to increase efficiency in ubiquitination routes in primates. The phylogenetic analysis suggests distinct evolutionary constraint between the analyzed genes. With these analyses, we hope to help clarify the correlation of the co-deletion of these genes and the more severe phenotype of NF1.

Distribution of FMR1 and FMR2 Repeats in Argentinean Patients with Primary Ovarian Insufficiency.

The premutation state of FMR1 (Fragile X Mental Retardation 1) has been associated with primary ovarian insufficiency (POI), and is the most common known genetic cause for 46,XX patients. Nevertheless, very few studies have analyzed its frequency in Latin American populations. Additionally, a relationship between alleles carrying a cryptic microdeletion in the 5'UTR of FMR2 and the onset of POI has only been studied in one population. Our aim was to analyze the incidence of FMR1 premutations and putative microdeletions in exon 1 of FMR2 in a cohort of Argentinean women with POI. We studied 133 patients and 84 controls. Fluorescent PCR was performed, and the FMR2 exon 1 was further sequenced in samples presenting less than 11 repeats. We found the frequency of FMR1 premutations to be 6.7% and 2.9% for familial and sporadic patients, respectively. Among controls, 1/84 women presented a premutation. In addition, although we did not find microdeletions in FMR2, we observed a change (T >C) adjacent to the repeats in two sisters with POI. Given the repetitive nature of the sequence involved, we could not ascertain whether this represents a single nucleotide polymorphism (SNP) or a deletion. Therefore, a relationship between FMR2 and POI could not be established for our population.

Heterogeneous contribution of microdeletions in the development of common generalised and focal epilepsies.

BACKGROUND: Microdeletions are known to confer risk to epilepsy, particularly at genomic rearrangement 'hotspot' loci. However, microdeletion burden not overlapping these regions or within different epilepsy subtypes has not been ascertained. OBJECTIVE: To decipher the role of microdeletions outside hotspots loci and risk assessment by epilepsy subtype. METHODS: We assessed the burden, frequency and genomic content of rare, large microdeletions found in a previously published cohort of 1366 patients with genetic generalised epilepsy (GGE) in addition to two sets of additional unpublished genome-wide microdeletions found in 281 patients with rolandic epilepsy (RE) and 807 patients with adult focal epilepsy (AFE), totalling 2454 cases. Microdeletions were assessed in a combined and subtype-specific approaches against 6746 controls. RESULTS: When hotspots are considered, we detected an enrichment of microdeletions in the combined epilepsy analysis (adjusted p=1.06×10-6,OR 1.89, 95% CI 1.51 to 2.35). Epilepsy subtype-specific analyses showed that hotspot microdeletions in the GGE subgroup contribute most of the overall signal (adjusted p=9.79×10-12, OR 7.45, 95% CI 4.20-13.5). Outside hotspots , microdeletions were enriched in the GGE cohort for neurodevelopmental genes (adjusted p=9.13×10-3,OR 2.85, 95% CI 1.62-4.94). No additional signal was observed for RE and AFE. Still, gene-content analysis identified known (NRXN1, RBFOX1 and PCDH7) and novel (LOC102723362) candidate genes across epilepsy subtypes that were not deleted in controls. CONCLUSIONS: Our results show a heterogeneous effect of recurrent and non-recurrent microdeletions as part of the genetic architecture of GGE and a minor contribution in the aetiology of RE and AFE.

Estandarización de un sistema PCR multiplex para la determinación molecular de infertilidad masculina idiopática

Objetivo: Diseñar y optimizar sistemas de reacción en cadena de polimerasa individuales y multiplex para la detección de microdeleciones de genes asociados a infertilidad masculina en el cromosoma Y. Métodos: Se estandarizaron sistemas de reacción en cadena de polimerasa multiplex utilizando oligonucleótidos STS (Sequence Target Site) específicos asociados a infertilidad masculina, con previa estandarización de cada par de oligos en reacciones individuales. Resultados: Se logró estandarizar 7 sistemas individuales y 2 sistemas multiplex de alta sensibilidad y especificidad que pueden indicar la presencia o ausencia de un gen, en este caso, son utilizados para indicar la mutación por microdeleción de algún fragmento específico de Yq que conlleva a la inactivación de un gen. Conclusiones: Se pudo realizar la estandarización de dos sistemas multiplex para el análisis de microdeleciones del cromosoma Y asociados a infertilidad masculina como una herramienta molecular para el diagnóstico rápido y preciso de esta patología. El amplificado del marcador RBM1 no pudo ser incluido en ninguna de los dos multiplex estandarizados, no obstante, se sugiere el estudio de otros marcadores de infertilidad masculina que puedan ser incluidos en la estandarización de nuevos multiplex.

Objective: To design and optimize individual systems and multiplex polymerase chain reaction for detection of microdeletions of male infertility associated genes on the Y chromosome. Methods: multiplex polymerase chain reaction systems were standardized using oligonucleotides STS (Sequence Target Site) specific to male infertility associated with prior standardization of each pair of oligos in individual reactions. Results: It was possible to standardize 7 individual systems and two multiplex systems high sensitivity and specificity that may indicate the presence or absence of a gene, in this case, are used to indicate the mutation microdeletion of a specific fragment Yq leading to the inactivation of a gene. Conclusions: standardization could make two multiplex systems for the analysis of microdeletions of the Y chromosome associated with male infertility as a molecular tool for rapid and accurate diagnosis of this disease. The amplified RBM1 marker could not be included in either standard multiplex, despite the studies of other markers of male infertility is suggested to be included in new in the standardization of new multiplexes.

Infertilidade masculina decorrente de microdeleções no cromossomo Y / Male infertility caused by microdeletions on Y chromosome

Objetivo: Abordar a infertilidade masculina causada pela microdeleção no cromossomo Y e apresentar possíveis tratamentos por meio das técnicas de reprodução humana assistida. Métodos: Levantamento de dados da literatura científica na área da medicina reprodutiva. Resultados: Quando comparadas com outras causas de infertilidade, as microdeleções do cromossomo Y são relativamente frequentes. O cromossomo Y é essencial para a determinação sexual masculina e no seu braço longo há regiões responsáveis pela espermatogênese. São elas AZFa, AZFb e AZFc. Essas regiões podem ser deletadas e por conter múltiplos genes essenciais para a espermatogênese podem causar infertilidade masculina. Graças aos avanços da medicina, hoje vários casos de infertilidade são tratáveis por meio das técnicas de reprodução assistida. Dentre as técnicas, a MSOME se destaca por ser uma metodologia que seleciona apenas espermatozoides morfologicamente normais para serem usados na inseminação e aumentar as chances de gestação. Conclusões: A infertilidade masculina tem aumentado consideravelmente nos últimos anos e as causas genéticas são uma das grandes consequências disso. As microdeleções do cromossomo Y podem causar desde uma oligozoospermia leve a uma azoospermia, a depender da região AZF afetada. Para as causas mais leves, o casal pode recorrer a algumas técnicas de reprodução assistida e para as causas mais graves a solução para o casal pode ser usar gametas doados.(AU)

Objective: Address male infertility caused by microdeletions on Y chromosome and present possible treatment through assisted human reproduction techniques. Methods: Survey data from the scientific literature in the field of reproductive medicine. Results: When compared with other causes of infertility, the microdeletions on Y chromosome are the relatively frequent. The Y chromosome is essential for male sex determination and there are in his long arm regions responsible for spermatogenesi, it's they AZFa, AZFb and AZFc. Such regions may be deleted causing male infertility by contain multiple genes essential for spermatogenesis. Thanks to advances in medicine, now several cases of infertility are treatable through assisted reproduction techniques. Among the techniques, the MSOME stands out as a methodology that selects only morphologically normal sperm to be used in insemination increasing the chances of pregnancy. Conclusions: Male infertility has increased considerably in recent years and the genetic causes are one ofthe major consequences ofthis. Y chromosome microdeletions can cause mild oligozoospermia or azoospermia depending on the AZF region affected. For lighter causes, the couple may use some assisted reproductive techniques and to the most serious causes the solution to the couple is using donated gametes.(AU)

Chromosomal and molecular abnormalities in a group of Brazilian infertile men with severe oligozoospermia or non-obstructive azoospermia attending an infertility service

PURPOSE: To determine the frequency of genetic alterations in a population of Brazilian infertile men with severe oligozoospermia or non-obstructive azoospermia. MATERIALS AND METHODS: Retrospective study of a group of 143 infertile men with severe oligozoospermia or non-obstructive azoospermia from the Andrology Outpatient Clinic of the Human Reproduction Service at the ABC School of Medicine. Of these patients, 100 had severe oligozoospermia, and 43 non-obstructive azoospermia. All patients underwent a genetic study which included karyotype analysis and Y-microdeletion investigation. RESULTS: Genetic abnormalities were found in 18.8 percent of the studied patients. Chromosomal abnormalities were found in 6.2 percent of the patients, being more prevalent in the azoospermia group (11.6 percent) than in the oligozoospermia group (4 percent). Chromosomal variants were found in 8.3 percent, and Y-chromosome microdeletions in 4.2 percent of patients. CONCLUSION: The high frequency of genetic alterations (18.8 percent) in our series justified performing a genetic investigation in a population with idiopathic infertility, as results may help determine the prognosis, as well as the choice of an assisted reproduction technique. Moreover, a genetic investigation could minimize the risk of transmitting genetic abnormalities to future generations such as genetic male infertility, mental retardation, genital ambiguity and/or birth defects.

Y chromosome microdeletions in Brazilian fertility clinic patients

Microdeletions in Yq are associated with defects in spermatogenesis, while those in the AZF region are considered critical for germ cell development. We examined microdeletions in the Y chromosomes of patients attended at the Laboratory of Human Reproduction of the Clinical Hospital of the Federal University of Goiás as part of a screening of patients who plan to undergo assisted reproduction. Analysis was made of the AZF region of the Y chromosome in men who had altered spermograms to detect possible microdeletions in Yq. Twenty-three patients with azoospermia and 40 with severe oligozoospermia were analyzed by PCR for the detection of six sequence-tagged sites: sY84 and sY86 for AZFa, sY127 and sY134 for AZFb, and sY254 and sY255 for AZFc. Microdeletions were detected in 28 patients, including 10 azoospermics and 18 severe oligozoospermics. The patients with azoospermia had 43.4% of their microdeletions in the AZFa region, 8.6% in the AZFb region and 17.4% in the AZFc region. In the severe oligozoospermics, 40% were in the AZFa region, 5% in the AZFb region and 5% in the AZFc region. We conclude that microdeletions can be the cause of idiopathic male infertility, supporting conclusions from previous studies.