Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Microdeletion”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,387 records · Page 77Linked to original sources
PubMed1999

The clinical management of male infertility.

Male infertility is a common cause of subfertility for which sperm disorders are the single most common cause. Genetic abnormalities, for example, microdeletions associated with the Y chromosome, defects in the androgen receptor gene and cystic fibrosis have gained recent prominence and it is envisaged that many of the 60% of men for which no cause is found may have a genetic basis for their subfertility. Although an abnormal semen analysis is commonly the first indicator of a male factor problem, further tests are usually required. Empirical treatment with hormones, varicocelectomy and immunological treatment have been proven to be disappointing whilst the treatment of infection and obstruction do not always translate into significantly higher fertility rates. Ejaculatory disorders and impotence can be effectively treated today whilst donor insemination can be offered to men with untreatable infertility. The advent of assisted reproduction and micromanipulation has greatly improved prospects for fertility of men with very poor semen quality. However, the genetic implications of these procedures have to be quickly addressed so that fertility is maximised without risk to the progeny.

Diagnosis, Differential↗
PubMed1999

[Genetic male infertility].

Several etiological factors in male infertility have been identified and it is now clear that a proportion of these factors have a genetic basis. This implies that using assisted reproductive technology procedures and especially intracytoplasmic sperm injection these genetic factors may be transmitted to the children. The following genetic factors involved in severe male infertility will be discussed: the presence of numerical and structural chromosomal anomalies, the occurrence of microdeletions on the long arm of the Y chromosome and the relation between cystic fibrosis and congenital bilateral absence of the vas deferens.

Chromosome Deletion↗
PubMed1999

Clinical and molecular findings in two patients with russell-silver syndrome and UPD7: comparison with non-UPD7 cases.

The clinical presentation of prenatal and postnatal growth deficiency, triangular face, relative macrocephaly, and body asymmetry is frequently diagnosed as Russell-Silver syndrome (RSS). Maternal uniparental disomy (UPD) of chromosome 7 was reported previously in a small subset of individuals with RSS phenotype or primordial growth retardation. The primary purpose of this study was to identify RSS patients with UPD7 and determine whether or not they present phenotypic findings that distinguish them from RSS patients without UPD7. UPD7 testing was performed in 40 patients with unexplained growth retardation, including 21 patients with a diagnosis of RSS. In addition, a subset of patients was screened with markers spanning chromosome 7 to detect potential microdeletions or segmental uniparental disomy. Two of the RSS cases were identified to have maternal UPD7; no cases with deletion or partial UPD were detected. Together with previously published studies, UPD7 was identified in 11/120 (9%) of individuals with classical RSS phenotype. Our patients with UPD7 and those previously published had a classical RSS phenotype and were not clinically distinguishable from other children diagnosed with RSS.

Abnormalities, Multiple↗
PubMed1999

[Fluorescence in situ hybridization in the study of chromosomal abnormalities].

Classical cytogenetics has a low resolving power and allows analysis of dividing cells only. In fluorescence in situ hybridization (FISH), a DNA fragment is stained with a fluorescent marker, after which this fragment is brought into contact with a patient's DNA. The stained fragment can bind to a corresponding fragment, revealing its presence or absence. Using FISH, every desired DNA sequence (from a whole chromosome to one gene) can be stained. In this way it is also possible to diagnose microdeletion syndromes, such as the Williams syndrome, the DiGeorge syndrome and submicroscopic chromosome anomalies that play a part in mental handicaps. FISH also allows analysis of non-dividing cells. In this way it is possible for instance rapidly to examine uncultured amniotic fluid cells for the commoner trisomies or to find foetal erythrocytes in a pregnant woman's blood. It is also possible to demonstrate tumour-specific breaking points. By application of FISH to microarrays it is possible to study a large number of genes simultaneously for the presence of a particular number of DNA sequences linked to a clinical abnormality.

Chromosome Aberrations↗
PubMed1999

[Teleradiographic analysis of velopharyngeal insufficiency in CATCH 22 association].

The CATCH 22 association (Cardiac defect, Abnormal facies, Thymic hypoplasia, Cleft palate, Hypocalcemia) combines certain signs common to various syndromes (Di-George syndrome, velocardiofacial syndrome, etc.) in combination with a 22q11 chromosomal microdeletion. Velopharyngeal insufficiency can be a complementary sign, or even a presenting sign of this chromosomal anomaly. After clinical examination of these patients, velopharyngeal insufficiency appeared to be due to a deep nasopharynx rather than to a short soft palate. We therefore reviewed 11 patients with teleradiography. We studied the length of the soft palate, the depth of the nasopharynx, the ratio of the depth of the nasopharynx over the length of the soft palate, and we compared our results with those observed in reference populations. The results demonstrate nasopharyngeal disproportion with a normal length of the soft palate and increased depth of the nasopharynx. This anatomical finding therefore encourages us to propose sphincteroplasty rather than velopharyngoplasty.

Abnormalities, Multiple↗
PubMed1999

[Blepharophimosis-ptosis-epicanthus inversus associated with infertility].

Blepharophimosis-ptosis-epicanthus syndrome (BPES) is a rare genetic condition occurring sporadically and transmitted by autosomal dominant inheritance. Type I BPES is associated with a high incidence of menstrual irregularities and infertility. Its clinical presentation is attributed to either an ovarian resistance to gonadotropins or to a true premature menopause. Two pathophysiological underlying mechanisms have been proposed: one suggests that one or more mechanisms lead to inhibition of early follicular development or follicule atresia. The other raises the possibility that BPES results from microdeletion of genetic material containing at least 2 independent genes. We report a familial case of BPES identified at birth and who required several surgical procedures. Several members of the patient's family are also affected. Early recognition of this condition may allow appropriate counselling and/or treatments including egg donation in case of hypergonadotropic hypogonadism.

Adult↗
PubMed2000

[The best of pediatric cardiology in 1999].

Paediatric cardiology is a dynamic field of progress for results. Those which have marked the year 1999 include the introduction of new techniques of cardiovascular imaging and interventional cardiology, and the new consequences of collaboration with workers in foetal cardiology and medical and molecular genetics. The advances in imaging are the result of those of microprocessors which enable three-dimensional reconstruction of ultrasonic, radiological or magnetic resonance images. This provides intracardiac or intravascular views which are very similar to those seen by the surgeon. This is a major tool for improving the diagnosis and treatment of congenital heart disease. Similarly, the introduction of programmes of tissue recognition enables fine ultrasonic analysis of the vascular wall and of endothelial function leading to the opening of a new chapter of preventive vascular medicine from the earliest age. Paediatric interventional cardiology has also progressed rapidly and the past year has been that of a consensus on the closure of a great number of atrial septal defects by new prostheses implanted and anchored in a simpler and safer manner. Prenatal diagnosis has become a crucial factor in the treatment and prognosis of congenital heart disease which is life-threatening in the first hours of life, explaining the benefit when this is applied to transposition of the great vessels or to coarctation of the aorta. Finally, advances in genetics have led to the identification of several genes of heart malformations and the correlations between interstitial microdeletions and syndromes often associated with heart disease: chromosome 22q11 and the Di George syndrome, chromosome 7q and the Williams syndrome. They have even allowed linking of myocardial and cerebellar abnormalities of a degenerative neuropathy (Friedreich's disease) to an abnormality of the mitochondrial respiratory chain, thus giving the opportunity of a real treatment.

Cardiology↗
PubMed2000

Dual-probe fluorescence in situ hybridization assay for detecting deletions associated with VCFS/DiGeorge syndrome I and DiGeorge syndrome II loci.

Over 90% of patients with DiGeorge syndrome (DGS) or velocardiofacial syndrome (VCFS) have a microdeletion at 22q11.2. Given that these deletions are difficult to visualize at the light microscopic level, fluorescence in situ hybridization (FISH) has been instrumental in the diagnosis of this disorder. Deletions on the short arm of chromosome 10 are also associated with a DGS-like phenotype. Since deletions at 22q11.2 and at 10p13p14 result in similar findings, we have developed a dual-probe FISH assay for screening samples referred for DGS or VCFS in the clinical laboratory. This assay includes two test probes for the loci, DGSI at 22q11.2 and DGSII at 10p13p14, and centromeric probes for chromosomes 10 and 22. Of 412 patients tested, 54 were found to be deleted for the DGSI locus on chromosome 22 (13%), and a single patient was found deleted for the DGSII locus on chromosome 10 (0. 24%). The patient with the 10p deletion had facial features consistent with VCFS, plus sensorineural hearing loss, and renal anomalies. Cytogenetic analysis showed a large deletion of 10p [46, XX,del(10)(p12.2p14)] and FISH using a 10p telomere region-specific probe confirmed the interstitial nature of the deletion. Analysis for the DGSI and the DGSII loci suggests that the deletion of the DGSII locus on chromosome 10 may be 50 times less frequent than the deletion of DGSI on chromosome 22. The incidence of deletions at 22q11.2 has been estimated to be 1 in 4000 newborns; therefore, the deletion at 10p13p14 may be estimated to occur in 1 in 200,000 live births.

Chromosome Deletion↗
PubMed2000

[Severe male infertility. Genetic investigation and counseling prior to intracytoplasmic sperm injections].

Intracytoplasmatic sperm injection (ICSI) has improved the success rate in treating severe male infertility. The method may now be used with sperm from the epididymis and testis. This article summarizes our knowledge on genetic factors affecting male gamete formation or function. Infertile men with severe impairment of spermatogenesis showed a higher than normal incidence of chromosomal abnormalities and 10-20% had microdeletion, in the Y-chromosome. About 75% of males with congenital bilateral absence of vas deferens (CBAVD) have mutations in the cystic fibrosis trans-membrane conductance regulator (CFTR) gene. In conclusion, we recommend genetic counselling to all couples with a diagnosis of male infertility prior to ICSI. Men with severe oligozoospermia or non-obstructive azoospermia should have karyotype analysis performed and with establishment of diagnostic tools to reveal Y-chromosome deletions, this should be offered to the same group of men. Men with obstructive azoospermia and congenital albilateral absence of vas deferens as well as their wives should be screened for cystic fibrosis mutations.

Chromosome Aberrations↗
PubMed2000

[Occurrence of X-linked ichthyosis along with atopy].

The cases of children indicate suffering from X-linked ichthyosis accompanied by atopic diseases (bronchial asthma, allergic rhinitis, allergic conjunctivitis, atopic dermatitis) which developed in infancy. The examinations revealed microdeletion of the steroid sulfatase region (Xp22.3), increased total IgE value and polysensibilization. It seems that the steroid sulphatase deficiency in ichthyosis played a role in the development of the atopic diseases. The present study suggests the commencement of a strict diet and antihistamine therapy, already in its infancy, in order to prevent the development of the accompanying atopic diseases.

Adolescent↗
PubMed2000

Apple peel atresia in association with bilateral colobomatous malformation of the optic nerve heads, dysmorphic features, and learning disability - a new syndrome?

Apple peel atresia of the small bowel is a rare congenital cause of intestinal obstruction. This case report describes a male patient with apple peel atresia and bilateral colobomatous malformation of the optic nerve heads in association with dysmorphic features and learning disabilities. In the absence of a positive family history, we propose that this collection of clinical findings could be due to a new dominant mutation or chromosomal microdeletion.

Child↗
PubMed2000

Tandem duplication/deletion in a maternally derived chromosome 9 supernumerary derivative resulting in 9p trisomy and partial 9q tetrasomy.

A 19-week stillborn female fetus with bilateral cleft palate, horseshoe kidney, bicornuate uterus, low-set ears, and intrauterine growth retardation (IUGR) was found to have a supernumerary derivative chromosome 9 (der(9)) with an apparent tandem duplication in the long arm. PCR analysis at five polymorphic loci confirmed the duplication and showed an adjacent deletion, while whole chromosome FISH demonstrated only chromosome 9 to be involved. Further FISH studies of der(9) found the 9qh region to be duplicated, telomeric sequences to be intact, and subtelomeric sequences to be absent. Thus, the fetus was determined to be trisomic for 9pter-->9q12 and 9q34.3-->9qter, tetrasomic for 9q12--> 9q33, and disomic for 9q33-->9q34.3. These results are consistent with a tandem duplication of 9q12-->9q33 and adjacent distal deletion as designated by the karyotype, 47,XX,+der(9)dup(9) (q12q33)del(9) (q33q34.3).ish der(9)(WCP9+,D9Z1x2,STP9q-, AHT+) de novo. In addition to characterizing der(9), the combined PCR and cytogenetic studies refined the Genome Database Map of three loci (D9S907, D9S155, and D9S302) approximately to the distal 9q33 region. Without the attempt to refine breakpoints by PCR analysis, the deletion in distal 9q would not have been detected. Tandem direct duplication/deletion chromosomes have been reported in fewer cases than inverted duplication/deletions. We propose mechanisms of origin, consistent with those for recurrent inter stitial microdeletion and microduplication syndromes, shown to arise by recombination at homologous, flanking DNA sequences.

Aneuploidy↗
PubMedDate not supplied

Screening for AZF deletion in a large series of severely impaired spermatogenesis patients.

Recent investigations have pointed to a high prevalence of Y chromosome submicroscopic deletions in men with severely impaired spermatogenesis. We report on the incidence in 128 infertile men, in whom karyotype, sperm count, and hormonal parameters were evaluated. Patients with abnormal karyotype (other than an abnormal Y chromosome) or sperm concentration of more than 2 million/mL were excluded. Genomic DNA was extracted from the peripheral leukocytes of 57 men with azoospermia and 71 with severe oligospermia. Molecular analysis was performed by 3 multiplex polymerase chain reactions using a set of 9 sequence tagged sites (STSs) from 3 different regions of the Y chromosome: AZFa, AZFb, and AZFc. In 7% of the studied patients Yq microdeletions were detected, with a high prevalence in men with azoospermia (14%). No deletions were detected in the AZFa region. Deletions were present in AZFb, AZFc, or both regions. The deletion observed in 1 patient that did not overlap with the DAZ region demonstrates that genes other than DAZ may also be involved in the pathogenesis of some subsets of male infertility. Furthermore, common Yq deletions present different testicular pictures, suggesting that some unknown factors may be disturbing spermatogenesis. Because men with severe infertility suffer a high risk of Y chromosome deletion, screening for these men is recommended prior to treatment with assisted reproduction.

Chromosome Aberrations↗
PubMed2000

Clinical and pathological observations in men lacking the gap junction protein connexin 32.

The X-linked form of Charcot-Marie-Tooth disease has been associated with mutations in the connexin 32 (Cx 32) gene, which encodes a gap junction protein. The majority of identified mutations are missense, but a few nonsense mutations or frame-shifting microdeletions have been encountered. Functional assessments of the mutated gap junction protein have demonstrated altered or simple losses of function. Mutations segregate with a typical clinical phenotype, which is the result of an age-related, progressive neuropathy. The mechanisms that cause the nerve damage are unknown. This report describes the consequences of a unique deletion mutation that eliminates the entire coding sequence of Cx 32, resulting in the absence of the Cx 32 gap junction protein in affected, hemizygous men. The clinical expression of this unique mutation was studied by the clinical, electrophysiological, and pathological evaluation of this kinship of five generations. The resulting severe neuropathy combines features of demyelination, notably in paranodal distribution, and distal accentuated axonal degeneration. The predicted absence of Cx 32 gap junctions is shown to be associated with a severe dysfunction of the axon-Schwann cell unit. Observed changes resemble those of Cx 32-null mice. No central nervous system changes were demonstrated.

Atrophy↗
PubMed2001

An overview of male infertility in the era of intracytoplasmic sperm injection.

As a result of the technological advance provided by intracytoplasmic sperm injection (ICSI) in 1992, the evaluation and treatment of the infertile male has changed significantly. Many men who were previously thought to be irreversibly infertile have the potential to initiate their own biologic pregnancy. However, not all men having impaired semen parameters are ideal candidates for ICSI for numerous reasons including a lack of addressing the underlying problem causing the male infertility, unknown genetic consequences, and cost-effectiveness issues. In this era of ICSI, the fundamental approach to the male with suspected subfertility is unchanged and is based on a history, physical examination, and focused laboratory testing. The urologist should approach the patient with an intent to identify remediable causes of subfertility given the specific clinical situation. For instance, should a gentleman have his varicocele repaired or vasectomy reversed, or should he proceed directly with ICSI? If no factors can be improved in a timely manner, then ICSI should be considered using the available sperm. Examples of recent advances include the diagnosis and treatment of ejaculatory duct obstruction, indications and techniques for performing testis biopsy, and techniques for sperm harvesting. Potential genetic causes should be diagnosed and discussed with the patient. Cystic fibrosis gene mutations, karyotype abnormalities, and Y-chromosome microdeletions all have recently been identified as causative for male infertility in otherwise phenotypically normal men. While the long-term genetic consequences for these offspring are largely undefined, recent studies suggest that serious birth defects are not significantly increased in ICSI babies. An understanding of these advances by all physicians is important as we progress into the 21st century.

Cystic Fibrosis Transmembrane Conductance Regulato↗
PubMedDate not supplied

[Prader-Willi syndrome large deletion on two brothers. Is this the exception that confirm the rule?].

INTRODUCTION: Prader-Willi syndrome (PWS), a neuroendocrine disorder could be due to: a large paternally derived chromosome deletion of 15q11-13, to maternal uniparental disomy (UPD), or imprinting mutation (IC); amongst this last group five families, with inherited microdeletion encompassing SNRPN were described; in these families excluded a typical large deletion. Families with more than a child with PWS by classic large deletion have not been published. CLINICAL CASES: We report on a family with three children, 2 of which had typical clinical findings of PWS: mental retardation, hypogonadism, hypotonia, hyperphagia, obesity and also strabismus and synophridia; during pregnancy reduced fetal movement was noted. The Fish probes (SNRPN and D15S10), Methylation specific PCR (MPCR), Southern blot and microsatellite markers confirmed in the PWS brothers a large deletion at least of the area comprising between D15S63 and GABRA5. CONCLUSIONS: No previously described cases in the literature reviewed show for PWS brothers due to a classical deletion. Some possible reasons recurrence in this family could be: at random, germinal mosaicism, or abnormalities at gonadal level environmental factors such as hydrocarbon exposing occupations in fathers of PWS patients as has been referred to by different authors. The latter might be an explanation as the father was working from age of 17 and for over 12 years with paints at shipyards exposed to hydrocarbon and others mutagenic substances. We consider it would be important to bear this case in mind when giving genetic counseling.

Blotting, Southern↗
PubMed2000

[Congenital cardiopathy in a data-based population].

Altogether 429.139 consecutive births were surveyed during the eighteen years study period by the Emilia-Romagna Registry. Among these, 2147 newborns with congenital heart defects (CHD) (prevalence 5 per 1000) were detected within the first week of life. There were 1607 isolated CHDs and 540 cases had other associated defects. During the study period an increase in prevalence/rate of CHDs was observed (from 3.1 per 1000 in 1980 to over 7 per 1000 in 1998), particularly isolated CHDs increased from 2.2 to 6 per 1000, while the prevalence rate of CHDs cases with other associated anomalies was constant ranging from 1 to 2 per 1000. The increase of isolated CHDs was due to the increased number of "minor" lesions such as ventricular (VSD) and atrial septal defect. The apparent increase in birth prevalence of CHD mainly results from improved diagnosis due to widespread use of color-doppler ecocardiography. As in other studies, a significant shift in the sex-ratio has been documented: a male predominance in transposition of great arteries, left hypoplastic heart and aortic stenosis (male/female ratio 2.2, 2.3, 4.5 respectively) were found; while VSD had a slight female excess (male/female ratio 0.96). The study confirmed that the majority of the affected parents were mothers. The recurrence risk of a cardiac defect in first degree relatives was 2.3%, while the recurrence risk of isolated conotruncal defects was 3.9%. Out of 47 cases with isolated conotruncal defects 4 had microdeletion of chromosome 22q11.2 and concerning the first degree relatives in one case the father had the deletion without CHD.

Female↗