1/57. child with velocardiofacial syndrome and del (4)(q34.2): another critical region associated with a velocardiofacial syndrome-like phenotype.We report on a child with congenital heart disease (atrial septal defect, ventricular septal defect, pulmonic stenosis), submucosal cleft palate, hypernasal speech, learning difficulties, and right fifth finger anomaly manifestations, consistent with velocardiofacial syndrome (VCFS); however, cytogenetic analysis demonstrated a small terminal deletion of the segment 4q34.2 to 4qter. Fluorescent in situ hybridization did not identify a deletion of the critical region associated with VCFS. In previously reported 4q deletions with a breakpoint distal to 4q34.2, no cardiac defects or cleft of palate were reported. Our patient has a deletion of 4q34.2 to 4qter and has palate and cardiac involvement and minor learning difficulties, which implies that genes involved in heart and palate development lie distal to 4q34.2, and that the critical region for more severe mental retardation on 4q may reside proximal to 4q34.2. These results suggest that a distal 4q deletion can lead to a phenotype similar to VCFS and emphasizes the importance of searching for other karyotype abnormalities when a VCFS-like phenotype is present and a 22q deletion is not identified.- - - - - - - - - - ranking = 1keywords = hybridization (Clic here for more details about this article) |
2/57. Delineation of two distinct 6p deletion syndromes.Deletions of the short arm of chromosome 6 are relatively rare, the main features being developmental delay, craniofacial malformations, hypotonia, and defects of the heart and kidney, with hydrocephalus and eye abnormalities occurring in some instances. We present the molecular cytogenetic investigation of six cases with 6p deletions and two cases with unbalanced translocations resulting in monosomy of the distal part of 6p. The breakpoints of the deletions have been determined accurately by using 55 well-mapped probes and fluorescence in situ hybridization (FISH). The cases can be grouped into two distinct categories: interstitial deletions within the 6p22-p24 segment and terminal deletions within the 6p24-pter segment. Characteristics correlating with specific regions are: short neck, clinodactyly or syndactyly, brain, heart and kidney defects with deletions within 6p23-p24; and corneal opacities/iris coloboma/Rieger anomaly, hypertelorism and deafness with deletions of 6p25. The two cases with unbalanced translocations presented with a Larsen-like syndrome including some characteristics of the 6p deletion syndrome, which can be explained by the deletion of 6p25. Such investigation of cytogenetic abnormalities of 6p using FISH techniques and a defined set of probes will allow a direct comparison of reported cases and enable more accurate diagnosis as well as prognosis in patients with 6p deletions.- - - - - - - - - - ranking = 1keywords = hybridization (Clic here for more details about this article) |
3/57. GATA4 haploinsufficiency in patients with interstitial deletion of chromosome region 8p23.1 and congenital heart disease.Previous studies have shown that patients with deletion of distal human chromosome arm 8p may have congenital heart disease and other physical anomalies. The gene encoding GATA-4, a zinc finger transcription factor implicated in cardiac gene expression and development, localizes to chromosome region 8p23.1. To examine whether GATA-4 deficiency is present in patients with monosomy of 8p23.1 with congenital heart disease, we performed fluorescence in situ hybridization (FISH) with a GATA4 probe on cells from a series of patients with interstitial deletion of 8p23.1. Four individuals with del(8)(p23.1) and congenital heart disease were found to be haploinsufficient at the GATA4 locus by FISH. The GATA4 gene was not deleted in a fifth patient with del(8)(p23.1) who lacked cardiac anomalies. FISH analysis on cells from 48 individuals with congenital heart disease and normal karyotypes failed to detect any submicroscopic deletions at the GATA4 locus. We conclude that haploinsufficiency at the GATA4 locus is often seen in patients with del(8)(p23.1) and congenital heart disease. Based on these findings and recent studies showing that haploinsufficiency for other cardiac transcription factor genes (e.g., TBX5, NKX2-5) causes congenital heart disease, we postulate that GATA-4 deficiency may contribute to the phenotype of patients with monosomy of 8p23.1.- - - - - - - - - - ranking = 1keywords = hybridization (Clic here for more details about this article) |
4/57. Ventricular noncompaction and distal chromosome 5q deletion.We describe a 7 1/2-year-old girl with mildly unusual phenotype and complex heart disease including ventricular myocardial noncompaction. She was found to have a distal 5q deletion, del(5)(q35.1q35.3). Fluorescent in situ hybridization showed that this deletion included the locus for the cardiac specific homeobox gene, CSX. This suggests that some instances of ventricular myocardial noncompaction may be caused by haploinsufficiency of CSX.- - - - - - - - - - ranking = 1keywords = hybridization (Clic here for more details about this article) |
5/57. Interstitial deletion of chromosome 5 in a neonate due to maternal insertion, ins(8;5)(p23;q33q35).We describe an infant girl with an interstitial deletion of chromosome bands 5q33 to 5q35 inherited from a maternal interchromosomal insertion ins(8;5)(p23;q33q35) which was demonstrated by fluorescent in situ hybridization with whole chromosome paints. Physical anomalies included hypertonicity, microcephaly, short neck, apparently low-set ears, micrognathia, camptodactyly, mild rocker bottom feet, and hammer toe. Cardiac anomalies included a large ventricular septal defect, patent ductus arteriosus, pulmonary hypertension and hypoplastic right ventricle. She died at age 3 months.- - - - - - - - - - ranking = 1keywords = hybridization (Clic here for more details about this article) |
6/57. Prenatal detection and mapping of a distal 8p deletion associated with congenital heart disease.We report the prenatal diagnosis, at 18 weeks' gestational age of a del(8)(p23.1-->pter) in a fetus with an atrio-ventricular canal, persistent left superior vena cava and hypoplastic right ventricle detected by sonographic imaging. We further refine the breakpoints associated with this defect using fluorescent in situ hybridization analysis (FISH). Our findings correlate with recent reports of the localization and importance of GATA4 (a zinc finger transcription factor) in cardiac development. Though microcephaly, mental retardation and typical behavioural features are well described in various deletions in 8p, the absence of notable microcephaly in this case raises the possibility for a separate genetic aetiology for some of these features. Indeed, primary autosomal recessive microcephaly (MCPH1) was recently mapped to a nearby region and may be the cause for this frequent observation in some cases of 8p deletions. These observations illustrate the role of FISH in prenatal diagnosis and refinement of chromosomal breakpoints. In addition, mappings of loci significant for cardiac development are presented. Our findings suggest that some features of the 8p deletion syndrome may ultimately be uncoupled from one another, and underscore the need for further study of this region of chromosome 8, in order to achieve adequate information for genetic counselling.- - - - - - - - - - ranking = 1keywords = hybridization (Clic here for more details about this article) |
7/57. Interstitial tandem duplication of 6p: a case with partial trisomy (6)(p12p21.3).A de novo interstitial tandem duplication of 6p12p21.3 was observed in a 7-month-old boy with growth retardation, psychomotor delay and craniofacial, brain, limb, and genital anomalies. Fluorescent in situ hybridization using a chromosome 6 paint probe demonstrated that the extra material belonged to chromosome 6. Although it has been suggested that 6p25 is the critical band involved in the expression of the phenotype of 6p duplication, comparison of the clinical findings of this case with those from the literature cases showed strong similarities.- - - - - - - - - - ranking = 1keywords = hybridization (Clic here for more details about this article) |
8/57. De novo 46,XX,t(6;7)(q27;q11;23) associated with severe cardiovascular manifestations characteristic of supravalvular aortic stenosis and williams syndrome.Supravalvular aortic stenosis may present as an isolated finding or as part of williams syndrome. williams syndrome is a contiguous gene syndrome associated with neurodevelopmental and multisystemic manifestations caused by hemizygous deletion at 7q11.23. We report on the prenatal and histopathological findings in a patient with a chromosome translocation involving the williams syndrome critical region. The initial abnormality on fetal ultrasound was hydrops fetalis detected at 30 weeks and echocardiography showed narrowing of the aorta and the pulmonary arteries. The baby died shortly after delivery and an autopsy revealed diffuse tubular thickening with luminal narrowing of the aorta, aortic branches, and the pulmonary arteries. Histopathology showed dysplasia of the media with reduced elastic content and "cartwheel" arrangement of collagen, elastic, and muscle fascicles. The karyotype was 46,XX,t(6;7)(q27;q11.23). Three signals were detected using the Oncor fluorescent in situ hybridization probe for elastin-williams syndrome (WSCR) suggesting that the break in chromosome 7 is within the elastin-Williams gene. This patient is of special interest because of the prenatal presentation and the chromosomal translocation involving the elastin-williams syndrome locus.- - - - - - - - - - ranking = 1keywords = hybridization (Clic here for more details about this article) |
9/57. Chiari malformation, cervical spine anomalies, and neurologic deficits in velocardiofacial syndrome.The purpose of this investigation was to evaluate the prevalence of Chiari malformation, cervical spine anomalies, and neurologic deficits in patients with velocardio-facial syndrome. This study was a prospective evaluation of 41 consecutive patients with velocardiofacial syndrome, documented by fluorescence in situ hybridization, between March of 1994 and September of 1998. The 23 girls and 18 boys ranged in age from 0.5 to 15.2 years, with a mean age of 6.7 years. Nineteen patients were assessed with magnetic resonance imaging, 39 underwent lateral cephalometric radiography, and all patients were examined for neurologic deficits. Eight of 19 patients (42 percent) had anomalies of the craniovertebral junction, including Chiari type I malformations (n = 4), occipitalization of the atlas (n = 3), and narrowing of the foramen magnum (n = 1). One patient with Chiari malformation required suboccipital craniectomy with laminectomy and decompression. Fourteen of 41 patients (34 percent) had demonstrated neurologic deficits; 10 patients (24 percent) had velar paresis (6 unilateral and 4 bilateral). Chiari malformations, cervical spine anomalies, and neurologic deficits are common in velocardiofacial syndrome. Because these findings may influence the outcome of surgical intervention, routine assessment of patients with velocardiofacial syndrome should include careful orofacial examination, lateral cephalometric radiography, and magnetic resonance imaging of the craniovertebral junction.- - - - - - - - - - ranking = 1keywords = hybridization (Clic here for more details about this article) |
10/57. Cardio-facio-cutaneous syndrome phenotype in an individual with an interstitial deletion of 12q: identification of a candidate region for CFC syndrome.We report on a 19-month-old girl who presented with the phenotype of cardio-faciocutaneous (CFC) syndrome including characteristic minor facial anomalies, cardiac defect, ectodermal anomalies, and developmental delay. cytogenetic analysis showed the presence of an interstitial deletion of one chromosome 12, del(12)(q21.2q22), confirmed by fluorescence in situ hybridization with chromosome band specific probes. Controversy exists as to whether CFC and noonan syndrome (NS) are distinct disorders, a contiguous gene syndrome, or allelic variants. The identification of the del(12) in this patient, in a region distinct from the putative NS locus, supports the view that CFC is a genetically distinct condition from NS. In addition, this implicates the region 12q21.2-->4q22 as a candidate region for the gene(s) causing CFC syndrome.- - - - - - - - - - ranking = 1keywords = hybridization (Clic here for more details about this article) |
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