ART in recurrent miscarriage: preimplantation genetic diagnosis/screening or surrogacy?

Recently, assisted reproductive techniques have been used to prevent further miscarriages in women with recurrent miscarriage. One approach uses either screening or diagnosis of embryonic chromosomes prior to embryo replacement [preimplantation genetic screening (PGS)/preimplantation genetic diagnosis (PGD)]. The second approach involves surrogacy. However, PGS/PGD assumes that the embryo is chromosomally abnormal, and that the mother should receive a chromosomally normal embryo. Surrogacy assumes that the embryo is normal and that the maternal environment needs to be substituted. This article examines the place of both techniques in different types of recurrent miscarriage, and tries to give guidelines as to which technique is preferable depending on the likelihood of an embryonic chromosome aberration. In repeated fetal aneuploidy or in the older patient, PGS or PGD are preferable. However, with high numbers of miscarriages, or in autoimmune pregnancy loss, surrogacy is preferable. In the light of recent work, it is uncertain which treatment mode is indicated in balanced parental chromosome aberrations. In conclusion, both techniques have a place, but probably only in those patients with a poor prognosis in whom assisted reproductive techniques will be shown to improve the subsequent live birth rate above the spontaneous rate.     

Gastrointestinal stromal tumors – definition, clinical, histological, immunohistochemical, and molecular genetic features and differential diagnosis

Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumors of the gastrointestinal (GI) tract. They are defined here as KIT (CD117, stem cell factor receptor)-positive mesenchymal spindle cell or epithelioid neoplasms primary in the GI tract, omentum, and mesentery. GISTs typically present in older individuals and are most common in the stomach (60-70%), followed by small intestine (20-25%), colon and rectum (5%), and esophagus (<5%). Benign tumors outnumber the malignant ones by a wide margin. Approximately 70% of GISTs are positive for CD34, 20-30% are positive for smooth muscle actin (SMA), 10% are positive for S100 protein and <5% are positive for desmin. The expression of CD34 and SMA is often reciprocal. GISTs commonly have activating mutations in exon 11 (or rarely exon 9 and exon 13) of the KIT gene that encodes a tyrosine kinase receptor for the growth factor named stem cell factor or mast cell growth factor. Ligand-independent activation of KIT appears to be a strong candidate for molecular pathogenesis of GISTs, and it may be a target for future treatment for such tumors. Other genetic changes in GISTs discovered using comparative genomic hybridization include losses in 14q and 22q in both benign and malignant GISTs and occurrence in various gains predominantly in malignant GISTs. GISTs have phenotypic similarities with the interstitial cells of Cajal and, therefore, a histogenetic origin from these cells has been suggested. An alternative possibility, origin of pluripotential stem cells, is also possible; this is supported by the same origin of Cajal cells and smooth muscle and by the common SMA expression in GISTs. GISTs differ clinically and pathogenetically from true leiomyosarcomas (very rare in the GI tract) and leiomyomas. The latter occur in the GI tract, predominantly in the esophagus (intramural tumors) and the colon and rectum (muscularis mucosae tumors). They also differ from schwannomas that are benign S100-positive spindle cell tumors usually presenting in the stomach. GI autonomic nerve tumors (GANTs) are probably a subset of GIST. Other mesenchymal tumors that have to be separated from GISTs include inflammatory myofibroblastic tumors in children, desmoid, and dedifferentiated liposarcoma. Angiosarcomas and metastatic melanomas, both of which are often KIT-positive, should not be confused with GISTs.     

Insomnia: symptom or diagnosis?

Is insomnia a clinical entity in its own right or is it simply a symptom of an underlying medical or psychological disorder? The widely held view among many clinicians and researchers is that insomnia is secondary to or an epiphenomenon of a 'primary' medical or psychological disorder. Consequently, insomnia 'symptoms' have tended to be trivialized or ignored. This paper aims to highlight the assumptions and implications of distinguishing between 'primary' and 'secondary' insomnia and reviews the evidence for the distinction by considering (1) issues relating to the diagnosis and classification of insomnia, (2) whether insomnia is a symptom of other medical and psychological disorders, (3) whether insomnia is comorbid with other disorders, (4) whether insomnia is 'secondary' to other disorders, and (5) whether insomnia occurs in the absence of comorbidity. It is concluded that viewing insomnia as a symptom or epiphenomenon of other disorders can be unfounded. This view may deprive many patients of treatment, which might not only cure their insomnia, but may also reduce symptoms associated with the assumed 'primary' disorder. Finally, directions for future research to further illuminate the relationship between insomnia and comorbid disorders are discussed.     

Essential thrombocythemia with deleted 5q - a genetic and morphologic hybrid?

A 66-year-old man who presented with progressive and marked thrombocytosis but normal hemoglobin was diagnosed to have essential thrombocythemia upon the demonstration of JAK2 V617F mutation. Bone marrow examination, however, showed the presence of monolobulated megakaryocytes and conventional cytogenetic analysis revealed an isolated interstitial deletion of the long arm of chromosome 5, characteristic of 5q− syndrome. A literature review indicated that isolated deletion of 5q is uncommon in essential thrombocythemia but that, when this isolated deletion is present, the disease often shows mixed features of both essential thrombocythemia and 5q− syndrome.     

Laboratory diagnosis of influenza--virology or serology?

Although classical influenza is a clinically typical illness ("unchanging disease due to a changing agent"), laboratory investigations are essential at the beginning of each influenza epidemic. They should confirm suspected influenza cases and exclude "flu-like illnesses" which may be caused by numerous other viral and bacterial agents. Different virological as well as serological methods are available. For early diagnosis of acute influenza virus infections, virus detection using rapid procedures for virus isolation or antigen staining and molecular biological techniques have been developed. The determination of specific antibodies (IgG, IgM) has traditionally been widely used diagnostically. Conventional serological diagnosis is possible by means of the complement fixation and hemagglutination inhibition tests and allows the detection of type- and subtype-specific antibodies, respectively. As part of an automated serology, immunofluorescence test and enzyme-linked immunosorbent assay are the mostly widely available methods. In comparison, virus detection is clearly superior to antibody determination for diagnosis of influenza virus infections. However, antibody testing may be useful as a complementary tool to confirm the diagnosis retrospectively.     

Primary immunodeficiencies and Bruton's disease genetic analysis: which prospects offers this genetic diagnosis?

Bruton's disease is the most frequently primary X-linked immunodeficiency. Bruton's tyrosine kinase (Btk) is encoded by the XLA gene that when mutated causes bruton's disease. This protein acts in multiple intracellular signaling pathways where the BCR (B-cell receptor) pathway is the most elucidated. Moreover 400 mutations were found and identified as responsible for B-cells differentiation block; consequences are a lack of B-cells in peripheral blood and hypo/agammaglobulinemia. Thus, patients are more susceptible to early and recurring infections occurring before the age of one year. Laboratory testing allow differential diagnosis among primary immunodeficiencies in which others hypogammaglobulinemia. Genetic analyses help physicians for clinical and biological diagnosis, and allow prenatal diagnosis for patient's family. Patient's management is based upon polyclonal immunoglobulin supplementation, infectious diseases prevention and genetic advice.     

Behcet’s disease: epidemiology,clinical manifestations,and diagnosis

Introduction: Behcet’s Disease (BD) is classified among vasculitides. The aim of this review was to put together different known reports in order to help the reader to better understand the disease, to avoid the frequent misdiagnosis, and to decide the best treatment.

Areas covered: a) Epidemiology: BD is rare, and is seen along the Silk Road, from 20 to 420/100,000 in Turkey and 80/100,000 in Iran, to 0.64/100,000 in the UK. b) Clinical manifestations: oral aphthosis is seen in more than 95% of patients, genital aphthosis (60–90%), skin (pseudofolliculitis/erythema nodosum, 40–90%), eyes (uveitis/retinal vasculitis, 45–90%), gastrointestinal (diarrhea/hemorrhage/perforation/pain, 4–38%), vascular (venous/arterial thrombosis, aneurysm, 2.2–50%), neurological (all kinds, especially meningo-encephalitis, 2.3–38.5%), and articular (arthralgia/arthritis/ankylosing spondylitis, 11.6–93%). c) Pathergy test is positive in some patients: 8.6% (in India) to 70.7% (in China). This data was extracted from the five nationwide surveys and the largest case series from BD conference reports and a Pubmed search.

Expert commentary: Diagnosis is clinical but classification/diagnosis criteria may help. The best criteria for BD is the International Criteria for Behcet’s Disease (ICBD). BD is a multisystem disease progressing by attacks and remissions. Each attack may resemble the preceding or it may be different in duration, severity, and the systems involved.     

Primary immunodeficiency or not? Making the correct diagnosis

Making a correct diagnosis of a primary immunodeficiency disease is crucial for the selection of proper therapy. Although many cases go undiagnosed, there are also many instances of incorrect diagnosis that result in years of inappropriate treatment and failure to implement beneficial treatment. This article summarizes 2 actual cases in which incorrect diagnoses led to recommendations of unwarranted high-risk or costly treatments. Had the physicians chosen tests of immune function rather than relying on immunoglobulin levels or cell counts, they would have arrived at the true diagnoses.     

Full karyotyping, rapid aneuploidy diagnosis or both when invasive prenatal testing is performed for diagnosis of thalassaemia?

A retrospective study was performed to compare the detection rate of chromosomal abnormalities by different approaches of full karyotyping, rapid aneuploidy diagnosis (RAD) or both when invasive prenatal testing is performed for diagnosis of thalassaemia. The karyotype results of 1120 prenatal samples obtained from thalassaemia couples from January 1985 to December 2002 in a referral centre for prenatal diagnosis were studied. The detection rate of chromosomal abnormalities by four different approaches were compared: (i) karyotyping for all samples; (ii) RAD (21,18,13,X,Y) for all samples; (iii) RAD for all samples + karyotyping for cases with ultrasound abnormalities; and (iv) RAD (21,18,13) for all + RAD (X,Y) for cases with ultrasound abnormalities consistent with Turner syndrome + karyotyping for cases with ultrasound abnormalities. Normal karyotypes were found in 1103 samples (98.5%). There were 17 cases (1.5%) of chromosomal abnormalities: four cases (0.36%) were clinically significant, eight cases (0.7%) were of borderline clinical significance and five cases (0.44%) were not confirmed by subsequent prenatal or postnatal tests. The incidences of autosomal (7/1120 = 0.63%) and sex chromosomal (5/1120 = 0.45%) abnormalities were not higher than those (0.41 and 0.22%, respectively) from newborn surveys (Hook and Hamerton, 1977) (P = 0.398 and 0.216, respectively). Approach 1 would detect all 17 chromosomal abnormalities. Approach 2 would detect three of four clinically significant chromosomal abnormalities but not detect six of eight chromosomal abnormalities of borderline clinical significance and three of five chromosomal abnormalities not confirmed by subsequent prenatal or postnatal tests. Approach 3, in addition, would be able to detect all four clinically significant chromosomal abnormalities. Approach 4 would detect all four clinically significant chromosomal abnormalities but would not detect seven of eight chromosomal abnormalities of borderline clinical significance and four of five chromosomal abnormalities not confirmed by subsequent prenatal or postnatal tests. RAD (21,18,13) for all + RAD (X,Y) for cases with ultrasound abnormalities consistent with Turner syndrome + karyotyping for cases with ultrasound abnormalities seemed to be the best approach for the detection of chromosomal abnormalities when invasive prenatal testing is performed for diagnosis of thalassaemia.     

Telomere loss: mitotic clock or genetic time bomb?

The Holy Grail of gerontologists investigating cellular senescence is the mechanism responsible for the finite proliferative capacity of somatic cells. In 1973, Olovnikov proposed that cells lose a small amount of DNA following each round of replication due to the inability of DNA polymerase to fully replicate chromosome ends (telomeres) and that eventually a critical deletion causes cell death. Recent observations showing that telomeres of human somatic cells act as a mitotic clock, shortening with age both in vitro and in vivo in a replication dependent manne, support this theory's premise. In addition, since telomeres stabilize chromosome ends against recombination, their loss could explain the increased frequency of dicentric chromosomes observed in late passage (senescent) fibroblasts and provide a checkpoint for regulated cell cycle exit. Sperm telomeres are longer than somatic telomeres and are maintained with age, suggesting that germ line cells may express telomerase, the ribonucleoprotein enzyme known to maintain telomere length in immortal unicellar eukaryotes. As predicted, telomerase activity has been found in immortal, transformed human cells and tumour cell lines, but not in normal somatic cells. Telomerase activation may be a late, obligate event in immortalization since many transformed cells and tumour tissues have critically short telomeres. Thus, telomere length and telomerase activity appear to be markers of the replicative history and proliferative potential of cells; the intriguing possibility remains that telomere loss is a genetic time bomb and hence causally involved in cell senescence and immortalization.     

Practices and ethical concerns regarding preimplantation diagnosis. Who regulates preimplantation genetic diagnosis in Brazil?

Preimplantation genetic diagnosis (PGD) was originally developed to diagnoseembryo-related genetic abnormalities for couples who present a high risk of aspecific inherited disorder. Because this technology involves embryo selection, themedical, bioethical, and legal implications of the technique have been debated,particularly when it is used to select features that are not related to seriousdiseases. Although several initiatives have attempted to achieve regulatoryharmonization, the diversity of healthcare services available and the presence ofcultural differences have hampered attempts to achieve this goal. Thus, in differentcountries, the provision of PGD and regulatory frameworks reflect the perceptions ofscientific groups, legislators, and society regarding this technology. In Brazil,several texts have been analyzed by the National Congress to regulate the use ofassisted reproduction technologies. Legislative debates, however, are not conclusive,and limited information has been published on how PGD is specifically regulated. Thecountry requires the development of new regulatory standards to ensure adequateaccess to this technology and to guarantee its safe practice. This study examinedofficial documents published on PGD regulation in Brazil and demonstrated how littledirect oversight of PGD currently exists. It provides relevant information toencourage reflection on a particular regulation model in a Brazilian context, andshould serve as part of the basis to enable further reform of the clinical practiceof PGD in the country.     

Neurofibromatosis-Noonan syndrome or LEOPARD Syndrome? A clinical dilemma

Neurofibromatosis (NF), Noonan syndrome (NS), and LEOPARD syndrome are all autosomal dominant conditions, each being a distinct clinical entity by itself. Rarely, one encounters cases with features of NF and NS and is termed as the 'Neurofibromatosis-Noonan syndrome' (NF-NS). The authors report a clinical dilemma with major clinical features of the NF-NS syndrome and LEOPARD syndrome co-existing in the same patient. Also, features of Noonan syndrome and LEOPARD syndrome are compared with the case reported.