17q23.3 de novo microdeletion involving only TANC2 gene: A new case.

Neurodevelopmental disorders (NDDs) show a wide range of overlapping clinical features. Intellectual disability (ID), developmental delay (DD), autism spectrum disorder (ASD), attention-deficit hyperactivity disorder (ADHD), language and communication disorders with or without motor abnormalities and/or epilepsy have been reported associated to single or multiple genes but in many cases the genetic basis remains unknown. The increasingly use of array-CGH has significantly improved the yield of diagnosing genomic disorders and led to the identification of several novel microdeletion and microduplication syndromes. TANC2 encodes a synaptic scaffold protein interacting with multiple neuropsychiatric disorder-related postsynaptic density (PSD) proteins in dendrites. Here, we describe a new case of TANC2 gene disruption in a 17q23.3 de novo microdeletion identified by array-CGH. The patient presented craniofacial dysmorphic features, hypotonia, and severe cognitive and motor impairment. In conclusion, our data add a further line of evidence supporting the role of TANC2 in NDDs and will help further researches to elucidate the regulatory mechanism of synaptic function and plasticity related to TANC2 haploinsufficiency.

Clinical and molecular delineation of a 16p13.2p13.13 microduplication.

The 16p13.3p13.1 region has been reported as a "critical" hotspot region for recurrent microdeletions/duplications, which may contribute to epilepsy, learning difficulties and facial dysmorphisms. Cytogenetic and array-CGH analyses were performed because of the clinical characteristics of the patient. The girl showed de novo 16p13.3p13.13 duplication spanning a region of ∼5.3 Mb. She presented brain anomalies, intellectual disability, epilepsy, facial and vertebral dysmorphisms. To our knowledge, this is the first reported case of 16p13.3p13.13 duplication; only three patients with an overlapping deletion in 16p13.2p13.13 were previously described. The duplicated region contains 21 OMIM genes and, six of them (RBFOX1, TMEM114, ABAT, PMM2, GRIN2A and, LITAF) were found to be associated with known diseases. Although no duplication of these genes has been described in the literature, we discuss here if they had some role in determining phenotype of our patient.

Pituitary deficiency and congenital infiltrating lipomatosis of the face in a girl with deletion of chromosome 1q24.3q31.1.

Interstitial deletions of the long arm of chromosome 1 are rare and they are classified as proximal or intermediate. The intermediate interstitial deletions span 1q24-1q32. We describe a 6-year-old girl with multiple pituitary hormone deficiency, severe cognitive impairment, bilateral cleft lip and palate, midline facial capillary malformation, erythema of hands and feet and dysplastic cranial vessels, low anti-thrombin III activity, hemifacial overgrowth due to progressive infiltrating lipomatosis with bone overgrowth, marked vascular proliferation and erythema of hands and feet, and abnormal cranial vessels. The girl's karyotype showed an apparently de novo interstitial deletion 1q24.3q31.1, which was defined by array-CGH. The deleted region contains numerous genes, but only eight (CENPL, LHX4, LAMC1, LAMC2, PTGS2, ANGPTL1, TNN, and TNR) are good candidates to explain, at least partially, the phenotype of the proposita. We, therefore, discuss the involvement of these genes and the observed phenotype.

Molecular cytogenetic characterization of the first reported case of an inv dup (4p)(p15.1-pter) with a concomitant 4q35.1-qter deletion and normal parents.

Inverted duplications associated with terminal deletions are complex anomalies described in an increasing of chromosome ends. We report on the cytogenetic characterization of the first de novo inv dup del(4) with partial 4p duplication and 4q deletion in a girl with clinical signs consistent with "recombinant 4 syndrome". This abnormality was suspected by banding, but high-resolution molecular cytogenetic investigations allowed us to define the breakpoints of the rearrangement. The terminal duplicated region extending from 4p15.1 to the telomere was estimated to be 29.27 Mb, while the size of the terminal deletion was 3.114 Mb in the 4q35.1 region. Until now, 10 patients with duplicated 4p14-p15 and deleted 4q35 chromosome 4 have been described. In all cases the abnormal chromosome 4 was derived from a pericentric inversion inherited from one of the parents. In conclusion, we have identified the first case of inv dup del(4) with normal parents suggesting that, often, terminal duplications or terminal deletions mask complex rearrangements.

Clinical spectrum of immunodeficiency, centromeric instability and facial dysmorphism (ICF syndrome).

BACKGROUND: Immunodeficiency, centromeric instability and facial dysmorphism (ICF syndrome) is a rare autosomal recessive disease characterised by facial dysmorphism, immunoglobulin deficiency and branching of chromosomes 1, 9 and 16 after PHA stimulation of lymphocytes. Hypomethylation of DNA of a small fraction of the genome is an unusual feature of ICF patients which is explained by mutations in the DNA methyltransferase gene DNMT3B in some, but not all, ICF patients. OBJECTIVE: To obtain a comprehensive description of the clinical features of this syndrome as well as genotype-phenotype correlations in ICF patients. METHODS: Data on ICF patients were obtained by literature search and additional information by means of questionnaires to corresponding authors. RESULTS AND CONCLUSIONS: 45 patients all with proven centromeric instability were included in this study. Facial dysmorphism was found to be a common characteristic (n = 41/42), especially epicanthic folds, hypertelorism, flat nasal bridge and low set ears. Hypo- or agammaglobulinaemia was demonstrated in nearly all patients (n = 39/44). Opportunistic infections were seen in several patients, pointing to a T cell dysfunction. Haematological malignancy was documented in two patients. Life expectancy of ICF patients is poor, especially those with severe infections in infancy or chronic gastrointestinal problems and failure to thrive. Early diagnosis of ICF is important since early introduction of immunoglobulin supplementation can improve the course of the disease. Allogeneic stem cell transplantation should be considered as a therapeutic option in patients with severe infections or failure to thrive. Only 19 of 34 patients showed mutations in DNMT3B, suggesting genetic heterogeneity. No genotype-phenotype correlation was found between patients with and without DNMT3B mutations.

A large analphoid invdup(3)(q22.3qter) marker chromosome characterized by array-CGH in a child with malformations, mental retardation, ambiguous genitalia and Blaschko's lines.

We report a new case of mosaic chromosome 3-derived marker chromosome, present in fibroblasts but not in lymphocytes, found in a child with malformations, mental retardation and ambiguous genitalia. Cytogenetic and molecular analysis showed that the supernumerary invdup(3)(q22.3qter) chromosome was negative at FISH with alpha satellite probe. The presence of a functional neocentromere was confirmed by immunofluorescence with antibodies to centromere proteins (CENPs). Definition of the marker breakpoints has been done through array-CGH. The skin of the patient presented dyschromic areas ordered along Blaschko's lines. The invdup(3q) marker chromosome was present only in fibroblasts from the dark skin biopsy, while lymphocytes and fibroblasts from the normal skin showed a normal male karyotype. Expression of the HPS3 gene (MIM: 606118) was more than two times higher in dark skin fibroblasts. Neocentromeres are most often observed on chromosomal arm fragments that have separated from an endogenous centromere, and therefore actually confer mitotic stability to what would have been acentric fragments. To our knowledge, this invdup(3q) analphoid marker is the largest among the several reported so far. Parental origin and possible mode of formation have been defined by DNA polymorphisms studies. The size of the duplicated marker chromosome and its frequency and tissue distribution may be relevant to the severity of the propositus' phenotype.

Correction for simultaneous catheter eccentricity and tilt in intravascular elastography.

Intravascular elastography can provide significant new information about the elastic properties of vascular tissue and plaque, useful for the diagnosis of disease and appropriate selection of interventional methods. Knowledge of the plaque composition, vulnerability and its elastic properties can assist the clinician in selecting appropriate interventional techniques. However, several noise sources have to be addressed to obtain quality intravascular elastograms. Misalignment of the vessel lumen and the ultrasound beam can produce erroneous strain estimates in elastography. Errors in the strain estimate are introduced due to the eccentricity and tilt of the intravascular transducer within the vessel lumen. Previous work in this area has provided theoretical expressions for the correction of eccentricity and tilt errors when they occur independent of each other. However, under most imaging conditions, both eccentricity and tilt errors are simultaneously present. In this paper, we extend the theoretical correction factor by accounting for the influence of both of these errors occurring simultaneously in the positioning of the catheter within the vessel lumen.

Carotid artery stenting in the first 100 consecutive patients: results and follow up.

BACKGROUND: Carotid artery stenting is now used as an alternative to surgical endarterectomy. The availability of cerebral protection systems has expanded the area of application of this procedure. OBJECTIVE: To assess the feasibility, safety, and immediate and late clinical outcome in patients undergoing percutaneous carotid interventions. METHODS: Between January 1999 and December 2000, 100 consecutive patients with 102 carotid artery stenoses were treated (71 men, 29 women, mean (SD) age 67 (8) years): 49 had coronary artery disease, 28 had previous stroke or transient ischaemic attack (TIA). On the basis of the Mayo Clinic carotid endarterectomy risk scale, 73 patients were grade III-IV and 13 grade VI. RESULTS: Baseline diameter stenosis was 78.8 (10)%, with a mean lesion length of 12.6 (5.8) mm. Angiographic success was obtained in 99 lesions (97.0%) with a final diameter stenosis of 2.4 (3.5)%. Procedural success was obtained in 96 patients (96%). Selective cannulation of three carotid arteries was impossible owing to severe vessel tortuosity. Carotid stenting was performed in 97 of the treated lesions, and protection devices were used in 67 lesions. In-hospital complications occurred in seven patients (six TIA, one (category 1) minor stroke). No major stroke or death occurred. All patients were discharged from the hospital after an average of 2.5 days. At 12 (6.2) months of follow up restenosis occurred in three patients (3.4%) (one patient with carotid occlusion had TIA). Six patients had died: two from cerebrovascular events (5 and 11 months after the procedure) and four from cardiovascular causes. CONCLUSIONS: Carotid stenting appears feasible and safe, with few major complications. Long term follow up is affected by a high incidence of cardiovascular mortality.

Immediate and long-term clinical and angiographic results from Wiktor stent treatment for true bifurcation narrowings.

From January 1996 to December 1998, 90 consecutive patients with true bifurcation lesions underwent percutaneous coronary angioplasty with Wiktor stent implantation in our centers. In 1 group (group I, n = 45), a simple approach (main vessel stenting and balloon angioplasty of the side branch) was pursued. In the other group (group II, n = 45), both the main vessel and the side branch were stented ("T" technique). There was no significant difference in clinical and angiographic characteristics between the 2 groups. Angiographic and procedural successes were 100% and 95.6%, respectively, in both groups. Angiographic results for the side branch were better in group II than in group I. In-hospital and long-term (12 month) major cardiac events were similar in the 2 groups. Target lesion revascularization was 15.5% in group I and 35.5% in group II (p = 0.12). In the main vessel, restenosis rate was 12.5% in group I and 25% in group II (p = 0.15). In the side branch, restenosis rate was 37.5% in group II and 12.5% in group I (p = <0.05; odds ratio 2.42; 95% confidence interval 1.05 to 6.26). Event-free probability at 12 months was 61% in group II and 80% in group I (p = 0.10). When dealing with true bifurcation lesions, a simple strategy is associated with a lower risk of restenosis in the side branch. In contrast, a complex approach does not appear to give any benefit in terms of early or long-term outcome or restenosis rate.

Satellite 2 methylation patterns in normal and ICF syndrome cells and association of hypomethylation with advanced replication.

Mutation in the DNMT3B DNA methyltransferase gene is a common cause of ICF (immunodeficiency, centromeric heterochromatin, facial anomalies) immunodeficiency syndrome and leads to hypomethylation of satellites 2 and 3 in pericentric heterochromatin. This hypomethylation is associated with centromeric decondensation and chromosomal rearrangements, suggesting that these satellite repeats have an important structural role. In addition, the satellite regions may have functional roles in modifying gene expression. The extent of satellite hypomethylation in ICF cells is unknown because methylation status has only been determined with restriction enzymes that cut infrequently at these loci. We have therefore developed a bisulfite conversion-based method to determine the detailed cytosine methylation patterns at satellite 2 sequences in a quantitative manner for normal and ICF samples. From our sequence analysis of unmodified DNA, the internal repeat region analyzed for methylation contains an average of 17 CpG sites. The average level of methylation in normal lymphoblasts and fibroblasts is 69% compared with 20% in such cells from ICF patients with DNMT3B mutations and 29% in normal sperm. Although the mean satellite 2 methylation values for these groups do not overlap, there is considerable overlap at the level of individual DNA strands. Our analysis has also revealed a pattern of methylation specificity, suggesting that some CpGs in the repeat are more prone to methylation than other sites. Variation in satellite 2 methylation among lymphoblasts from different ICF patients has prompted us to determine the frequency of cytogenetic abnormalities in these cells. Although our data suggest that some degree of hypomethylation is necessary for pericentromeric decondensation, factors other than DNA methylation appear to play a major role in this phenomenon. Another such factor may be altered replication timing because we have discovered that the hypomethylation of satellite 2 in ICF cultures is associated with advanced replication.

Late acute thrombosis after coronary brachytherapy: when is the risk over?

Late total occlusion (LTO) after simultaneous coronary stenting and brachytherapy has been described in recent randomized trials. We report a case of LTO presenting with an acute clinical event 15 months after the index procedure, suggesting that the risk is not confined to the first 6-month to 1-year period.

Olfactory receptor-gene clusters, genomic-inversion polymorphisms, and common chromosome rearrangements.

The olfactory receptor (OR)-gene superfamily is the largest in the mammalian genome. Several of the human OR genes appear in clusters with > or = 10 members located on almost all human chromosomes, and some chromosomes contain more than one cluster. We demonstrate, by experimental and in silico data, that unequal crossovers between two OR gene clusters in 8p are responsible for the formation of three recurrent chromosome macrorearrangements and a submicroscopic inversion polymorphism. The first two macrorearrangements are the inverted duplication of 8p, inv dup(8p), which is associated with a distinct phenotype, and a supernumerary marker chromosome, +der(8)(8p23.1pter), which is also a recurrent rearrangement and is associated with minor anomalies. We demonstrate that it is the reciprocal of the inv dup(8p). The third macrorearrangment is a recurrent 8p23 interstitial deletion associated with heart defect. Since inv dup(8p)s originate consistently in maternal meiosis, we investigated the maternal chromosomes 8 in eight mothers of subjects with inv dup(8p) and in the mother of one subject with +der(8), by means of probes included between the two 8p-OR gene clusters. All the mothers were heterozygous for an 8p submicroscopic inversion that was delimited by the 8p-OR gene clusters and was present, in heterozygous state, in 26% of a population of European descent. Thus, inversion heterozygosity may cause susceptibility to unequal recombination, leading to the formation of the inv dup(8p) or to its reciprocal product, the +der(8p). After the Yp inversion polymorphism, which is the preferential background for the PRKX/PRKY translocation in XX males and XY females, the OR-8p inversion is the second genomic polymorphism that confers susceptibility to the formation of common chromosome rearrangements. Accordingly, it may be possible to develop a profile of the individual risk of having progeny with chromosome rearrangements.

Surgical and percutaneous myocardial angiogenesis induction. Part II--neoangiogenesis.

Coronary artery bypass surgery and angioplasty provide symptomatic relief in patients with ischemic heart disease, but despite advancement in technique and devices, these methods are not applicable to a subset of patients with angina refractory to medical treatment. Bypass surgery might not be feasible because of lack of suitable conduits, diffuse coronary disease or poor distal run-off, and coronary angioplasty is sometimes not applicable due to chronic total occlusion, diffuse disease or extreme tortuosity. We have previously reviewed the available experience with laser-induced direct myocardial revascularization, one of the new potential treatment modalities for this patient subset. One of the potential mechanisms of action for laser treatment is the induction of neoangiogenesis. In the second part of our article we review the available experience with the induction of myocardial angiogenesis using different growth factors or the genes encoding for them.

Intravascular ultrasound criteria for the assessment of the functional significance of intermediate coronary artery stenoses and comparison with fractional flow reserve.

The functional significance of coronary artery stenoses of intermediate severity is important in determining strategy in patient care. Intravascular ultrasound (IVUS) is often used to evaluate coronary stenosis severity. However, at present, few data are available about the role IVUS in the assessment of functional significance of intermediate lesions. Myocardial fractional flow reserve (FFR) <0.75 is a reliable index of a functionally severe coronary stenosis. In 53 lesions we assessed (1) by pressure wire: FFR (index of functional significance), and (2) by IVUS: minimal lumen cross-sectional area (MLA, square millimeters), minimal lumen diameter (MLD, millimeters), lesion length (millimeters), and percent area stenosis at the lesion site. By regression analysis, percent area stenosis and lesion length had a significant inverse correlation with FFR (r = -0.58, p <0.001, r = -0.41, p <0.004, respectively). MLD and MLA showed a significant positive relation with FFR (r = 0.51, p <0.001, r = 0.41, p <0.004, respectively). By using a receiver operating characteristic (ROC) curve, we identified a percent area stenosis > 70% (sensitivity 100%, specificity 68%), a MLD < or = 1.8 mm (sensitivity 100%, specificity 66%), a MLA < or =4.0 mm2 (sensitivity 92%, specificity 56%), and a lesion length of >10 mm (sensitivity 41%, specificity 80%) to be the best cut-off values to fit with a FFR <0.75. The combined evaluation of both percent area stenosis and MLD made the IVUS examination more specific (sensitivity 100%, specificity 76%). In 53 intermediate coronary lesions found by angiography, IVUS area stenosis >70%, MLD < or =1.8 mm, MLA < or =4.0 mm2, and lesion length > 10 mm reliably identified functionally critical intermediate coronary stenoses.

Escape from gene silencing in ICF syndrome: evidence for advanced replication time as a major determinant.

Chromosomal abnormalities associated with hypomethylation of classical satellite regions are characteristic for the ICF immunodeficiency syndrome. We, as well as others, have found that these effects derive from mutations in the DNMT3B DNA methyltransferase gene. Here we examine further the molecular phenotype of ICF cells and report several examples of extensive hypomethylation that are associated with advanced replication time, nuclease hypersensitivity and a variable escape from silencing for genes on the inactive X and Y chromosomes. Our analysis suggests that all genes on the inactive X chromosome may be extremely hypomethylated at their 5' CpG islands. Our studies of G6PD in one ICF female and SYBL1 in another ICF female provide the first examples of abnormal escape from X chromosome inactivation in untransformed human fibroblasts. XIST RNA localization is normal in these cells, arguing against an independent silencing role for this RNA in somatic cells. SYBL1 silencing is also disrupted on the Y chromosome in ICF male cells. Increased chromatin sensitivity to nuclease was found at all hypomethylated promoters examined, including those of silenced genes. The persistence of inactivation in these latter cases appears to depend critically on delayed replication of DNA because escape from silencing was only seen when replication was advanced to an active X-like pattern.