92 research outputs found
Part 2: A Pilot Ethnomethodological Study
This second paper reports on a small ethnographic study of Argentine psychiatrists. A carefully selected group of six psychiatrists currently practicing in Buenos Aires par- ticipated in an in-depth semi-structured interview. The transcripts of the interviews were coded and a thematic analysis method was applied to construct a local theory of the professional values constructed by Argentine psy- chiatrists, and the circumstances in which such values were constructed. Our analysis indicated that Argentine psychia- trists constructed a number of values, frequently perceived as obligations to their professional group and the needs of their patients. The two main strategies employed by Ar- gentine psychiatrists were the diagnostic act and advocacy. We also identify that these values emerge in the context of recent broad historical and cultural influences upon the profession of psychiatry in Argentina, and the Argentine population in general
Development of a genotyping microarray for Usher syndrome
BACKGROUND: Usher syndrome, a combination of retinitis pigmentosa (RP) and sensorineural hearing loss with or without vestibular dysfunction, displays a high degree of clinical and genetic heterogeneity. Three clinical subtypes can be distinguished, based on the age of onset and severity of the hearing impairment, and the presence or absence of vestibular abnormalities. Thus far, eight genes have been implicated in the syndrome, together comprising 347 protein-coding exons. METHODS: To improve DNA diagnostics for patients with Usher syndrome, we developed a genotyping microarray based on the arrayed primer extension (APEX) method. Allele-specific oligonucleotides corresponding to all 298 Usher syndrome-associated sequence variants known to date, 76 of which are novel, were arrayed. RESULTS: Approximately half of these variants were validated using original patient DNAs, which yielded an accuracy of >98%. The efficiency of the Usher genotyping microarray was tested using DNAs from 370 unrelated European and American patients with Usher syndrome. Sequence variants were identified in 64/140 (46%) patients with Usher syndrome type I, 45/189 (24%) patients with Usher syndrome type II, 6/21 (29%) patients with Usher syndrome type III and 6/20 (30%) patients with atypical Usher syndrome. The chip also identified two novel sequence variants, c.400C>T (p.R134X) in PCDH15 and c.1606T>C (p.C536S) in USH2A. CONCLUSION: The Usher genotyping microarray is a versatile and affordable screening tool for Usher syndrome. Its efficiency will improve with the addition of novel sequence variants with minimal extra costs, making it a very useful first-pass screening tool
Social and medical need for whole genome high resolution NIPT
Background: Two technological innovations in the last decade significantly influenced the diagnostic yield of prenatal cytogenetic testing: genomic microarray allowing high resolution analysis and noninvasive prenatal testing (NIPT) focusing
on aneuploidy. To anticipate future trends in prenatal screening and diagnosis, we
evaluated the number of invasive tests in our center and the number of aberrant cases
diagnosed in the last decade.
Methods: We retrospectively analyzed fetal chromosomal aberrations diagnosed in
2009–2018 in 8,608 pregnancies without ultrasound anomalies.
Results: The introduction of NIPT as the first-tier test led to a substantial decrease
in the number of invasive tests and a substantially increased diagnostic yield of aneuploidies in the first trimester. However, we have also noted a decreased detection
of submicroscopic aberrations, since the number of invasive tests substantially decreased. We have observed that pregnant women were interested in broader scope of
prenatal screening and diagnosis than detection of common trisomies.
Conclusion: Since the frequency of syndromic disorders caused by microdeletions/
microduplications is substantial and current routine NIPT and ultrasound investigations are not able to detect them, we suggest that a noninvasive test with resolution
comparable to microarrays should be developed, which will also meet patient's needs
Heterozygous missense variants of LMX1A lead to nonsyndromic hearing impairment and vestibular dysfunction
Neuro Imaging Researc
Segmental and total uniparental isodisomy (UPiD) as a disease mechanism in autosomal recessive lysosomal
Analyses in our diagnostic DNA laboratory include genes involved in autosomal recessive (AR) lysosomal storage disorders
such as glycogenosis type II (Pompe disease) and mucopolysaccharidosis type I (MPSI, Hurler disease). We encountered 4
cases with apparent homozygosity for a disease-causing sequence variant that could be traced to one parent only. In addition,
in a young child with cardiomyopathy, in the absence of other symptoms, a diagnosis of Pompe disease was considered.
Remarkably, he presented with different enzymatic and genotypic features between leukocytes and skin fibroblasts. All cases
were examined with microsatellite markers and SNP genotyping arrays. We identified one case of total uniparental disomy
(UPD) of chromosome 17 leading to Pompe disease and three cases of segmental uniparental isodisomy (UPiD) causing
Hurler-(4p) or Pompe disease (17q). One Pompe patient with unusual combinations of features was shown to have a mosaic
segmental UPiD of chromosome 17q. The chromosome 17 UPD cases amount to 11% of our diagnostic cohort of
homozygous Pompe patients (plus one case of pseudoheterozygosity) where segregation analysis was possible. We conclude
that inclusion of parental DNA is mandatory for reliable DNA diagnostics. Mild or unusual phenotypes of AR diseases
should alert physicians to the possibility of mosaic segmental UPiD. SNP genotyping arrays are used in diagnostic workup
of patients with developmental delay. Our results show that even small Regions of Homozygosity that include telomeric
areas are worth reporting, regardless of the imprinting status of the chromosome, as they might indicate segmental UPiD
Molecular diagnosis of hereditary hearing impairment.
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PCR analysis of Y-chromosome deletions in subfertile men
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24615___.PDF (publisher's version ) (Open Access
Outcome of ABCA4 microarray screening in routine clinical practice
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81657.pdf (publisher's version ) (Open Access)PURPOSE: To retrospectively analyze the clinical characteristics of patients who were screened for mutations with the ATP-binding cassette transporter gene ABCA4 (ABCA4) microarray in a routine clinical DNA diagnostics setting. METHODS: We performed a retrospective analysis of the medical charts of 65 patients who underwent an ABCA4 microarray screening between the years 2002 and 2006. An additional denaturing gradient gel electrophoresis (DGGE) was performed in these patients if less than two mutations were found with the microarray. We included all patients who were suspected of autosomal recessive Stargardt disease (STGD1), autosomal recessive cone-rod dystrophy (arCRD), or autosomal recessive retinitis pigmentosa at the time of microarray request. After a retrospective analysis of the clinical characteristics, the patients who were suspected of STGD1 were categorized as having either a typical or atypical form of STGD1, according to the age at onset, fundus appearance, fluorescein angiography, and electroretinography. The occurrence of typical clinical features for STGD1 was compared between patients with different numbers of discovered mutations. Results : Of the 44 patients who were suspected of STGD1, 26 patients (59%) had sufficient data available for a classification in either typical (six patients; 23%) or atypical (20 patients; 77%) STGD1. In the suspected STGD1 group, 59% of all expected pathogenic alleles were found with the ABCA4 microarray. DGGE led to the finding of 12 more mutations, resulting in an overall detection rate of 73%. Thirty-one percent of patients with two or three discovered ABCA4 mutations met all typical STGD1 criteria. An age at onset younger than 25 years and a dark choroid on fluorescein angiography were the most predictive clinical features to find ABCA4 mutations in patients suspected of STGD1. In 18 patients suspected of arCRD, microarray screening detected 22% of the possible pathogenic alleles. CONCLUSIONS: In addition to confirmation of the diagnosis in typical STGD1, ABCA4 microarray screening is usually requested in daily clinical practice to strengthen the diagnosis when the disease is atypical. This study supports the view that the efficiency and accuracy of ABCA4 microarray screening are directly dependent upon the clinical features of the patients who are screened
Microdeleties van het Y-chromosoom bij mannen op de wachtlijst voor intracytoplasmatische sperma-injectie
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24405___.PDF (publisher's version ) (Open Access
[From gene to disease; deletion of the DAZ-gene from the Y-chromosome in oligo- or azoospermia ]
Item does not contain fulltextDAZ gene deletions at the azoospermia factor (AZF) locus on the Y chromosome, have been implicated as one of the major causes of idiopathic male subfertility. Deletions of the entire DAZ gene have been reported in azoospermia as well as in oligozoospermia. The DAZ gene encodes a RNA binding protein which is expressed exclusively in germ cells. The exact biological role and function of the DAZ protein has yet to be resolved
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