1/14. prenatal diagnosis of partial trisomy 3p(3p23-->pter) and monosomy 7q(7q36-->qter) in a fetus with microcephaly alobar holoprosencephaly and cyclopia.We report the prenatal diagnosis of partial trisomy 3p(3p23-->pter) and monosomy 7q(7q36-->qter) in a fetus with microcephaly, alobar holoprosencephaly and cyclopia. A 26-year-old primigravida woman was referred for genetic counselling at 23 gestational weeks due to sonographic findings of intra-uterine growth retardation and cranio-facial abnormalities. Level II ultrasonograms further demonstrated alobar holoprosencephaly, a proboscis above the eye and a single median orbit consistent with cyclopia. Genetic analysis and fluorescence in situ hybridization on cells obtained from amniocentesis showed distal 3p trisomy (3p23-->pter) and 7q36 deletion, 46,XX,der(7)t(3;7)(p23;q36), resulting from a paternal t(3;7) reciprocal translocation. The pregnancy was terminated. autopsy further confirmed the presence of arrhinencephaly, agenesis of the corpus callosum and a single ventricle of the brain. The phenotype of this antenatally diagnosed case is compared with those observed in 10 previously reported cases with simultaneous occurrence of partial trisomy 3p and terminal deletion 7q. All cases are associated with severe forms of holoprosencephaly and facial dysmorphism. This delineates an autosomal imbalance syndrome or a dosage effect involving duplication of distal 3p/deficiency of terminal 7q and dysmorphogenesis of the forebrain and mid-face.- - - - - - - - - - ranking = 1keywords = hybridization (Clic here for more details about this article) |
2/14. corpus callosum agenesis, multiple cysts, skin defects, and subtle ocular abnormalities with a de novo mutation [45,XX,der(5), t(5;;14) (pter;q11.2)].We report on a 2-year-old girl with a de novo mutation [45,XX,der(5),t(5;14) (pter;q11.2)] with corpus callosum agenesis, multiple cysts (cerebral and cardiac), subtle eye abnormalities, and at least two different skin defects, strongly indicating neuroectodermal involvement, as a neuromuscular choristoma (hamartoma) and an eccrine hamartoma. Fluorescent in situ hybridization with different single-locus probes showed that chromosome 5 has a very small deletion, confined to a region composed of repetitive sequences. By contrast, the long (q) arm of chromosome 14 seems to be much more involved in the rearrangement, with partial monosomy spanning from the centromere to the D14S72 and D14S261 loci. The extent of the deleted region of chromosome 14 is approximately 16 cM. To our knowledge, this is the smallest reported deletion involving the chromosome 14q11.2 region to be associated with a developmental disorder resulting in variable eye, skin, and brain anomalies. We suggest that a new syndrome, mimicking in some ways the MLS phenotype, is caused by a deletion in the chromosome 14q11.2 region.- - - - - - - - - - ranking = 1keywords = hybridization (Clic here for more details about this article) |
3/14. Possible third case of Lin-Gettig syndrome.We report a patient with craniosynostosis, severe mental retardation, absence of the corpus callosum, camptodactyly, hypogonadism, and ventricular septal defect. We propose that he has Lin-Gettig syndrome and that he is the third reported patient with this entity. Our patient also had additional phenotypic features, including palatal cleft and absent rapid eye movement (REM) sleep that were not present in the two previously described patients with this syndrome. High-resolution karyotype and subtelomeric fluorescence in situ hybridization (FISH) for cryptic telomeric rearrangement were normal. The existence of an unrelated patient with Lin-Gettig syndrome supports that this is a separate and distinct clinical entity.- - - - - - - - - - ranking = 1keywords = hybridization (Clic here for more details about this article) |
4/14. FOXC1 gene deletion is associated with eye anomalies in ring chromosome 6.We report a case of ring chromosome 6 presenting with growth and mental retardation, cerebral dysgenesis, eye malformations, mixed hearing loss, and abnormal physical features. Fluorescent in situ hybridization (FISH) and microsatellite genotyping demonstrated segmental deletions of less than 6 Mb on 6p and 1-2 Mb on 6q. The primary karyotype is designated as 46,XY,r(6)(p25q27).ish r(6)(p25.1q27)(D6S344-, FOXC1-, D6S1574 , D6S281-, D6S297 ). Secondary structural and numerical variants of the ring 6 were observed in 16% of the cells analyzed. Intragenic genotyping revealed deletion of the paternal FOXC1 gene, haploinsufficiency of which has been reported to cause eye anterior chamber developmental defects. Accordingly, we propose that our patient's ophthalmologic abnormalities result from haploinsufficiency of the transcription factor FOXC1. We present clinical and cytogenetic summaries on 23 reported cases of ring 6 and categorize them into mild, moderate, and severely affected groups. Further phenotype comparisons between cases with ring 6 and cases with only 6p or 6q terminal deletions suggest that genes important for hearing, vision, and central nervous system development remain to be identified in chromosome 6 terminal regions. Molecular definition of the fusion points and tissue mosaicism studies are necessary to better understand the genotype-phenotype correlation of ring 6. We recommend ophthalmology, audiology, cardiology, and central nervous system examinations be part of the routine evaluation for children with a ring chromosome 6.- - - - - - - - - - ranking = 1keywords = hybridization (Clic here for more details about this article) |
5/14. microcephaly, jejunal atresia, aberrant right bronchus, ocular anomalies, and XY sex reversal.We present a patient with microcephaly, jejunal atresia, aberrant right tracheobronchial tree, mild left blepharoptosis, and corectopia (irregular pupil), left sectoral iris stromal hypoplasia and peripheral anterior synechia, and 46,XY sex reversal. Testosterone and dihydrotestosterone (DHT) levels were within normal limits for a male infant at 3 weeks of age. Gonadectomy at age 18 months revealed immature testis tissue and no evidence of Mullerian structures. PCR amplification of the androgen receptor (AR) gene and flanking genomic regions revealed no evidence for deletion. Array-comparative genomic hybridization (array-CGH) for assessment of gene dosage in other regions of the genome was normal. This patient represents a multiple anomaly disorder similar to intestinal atresia-ocular anomalies-microcephaly syndrome (MIM#243605) but incorporating 46,XY sex reversal with testicular tissue, demonstrating a defect in the sexual differentiation pathway.- - - - - - - - - - ranking = 1keywords = hybridization (Clic here for more details about this article) |
6/14. Subtelomeric 6p deletion: clinical, FISH, and array CGH characterization of two cases.Thirty patients have been described with cytogenetically visible deletion of the short arm of chromosome 6. However, subtelomeric 6p deletion detected by subtelomeric specific probes has been reported only twice. We report two new patients with terminal 6p deletion detected by subtelomeric screening using fluorescence in situ hybridization (FISH). The two patients exhibited mental retardation, ocular abnormalities, hearing loss, and a characteristic facial appearance. Detailed FISH analyses with probes covering the distal 6p25 region estimated the size of the terminal deletions to approximately 5.5 Mb and approximately 4.8 Mb. Array-based comparative genomic hybridization (array CGH) was used to confirm the cryptic deletions. Most patients with subtelomeric defects lack a characteristic phenotype. However, some of the subtelomeric deletions result in a specific phenotype, which can direct the clinician towards the diagnosis. Submicroscopic 6p deletion appears to be a recognizable clinical phenotype, and this region should be thoroughly investigated with FISH probes, including at least a subtelomeric 6p probe and a probe covering FOXC1, for patients presenting with a characteristic facial appearance, ocular abnormalities, predominantly anterior-chamber eye defects, hearing loss, and mental retardation.- - - - - - - - - - ranking = 2keywords = hybridization (Clic here for more details about this article) |
7/14. schizophrenia in an adult with 6p25 deletion syndrome.Chromosomal deletions at 6p25-p24 are rare findings in patients with developmental delay. There is limited information about the adult phenotype. We present a 36-year-old patient with schizophrenia, mild mental retardation, progressive hearing deficits, and characteristic facial features. Ocular (Axenfeld-Rieger anomaly) abnormalities were diagnosed in infancy; vision, however, has remained unimpaired. There were no other major congenital anomalies. brain imaging showed only minor changes. There was no family history of intellectual deficits or psychosis. karyotyping revealed a 6p25 deletion, and detailed fluorescence in situ hybridization (FISH) analyses using 23 probes confirmed a 6.7 Mb 6p25-pter deletion. The breakpoint is near a possible 6p25-p24 locus for schizophrenia. Psychotic illness may be part of the neurodevelopmental abnormalities and long-term outcome of patients with 6p terminal deletions. Other similarly affected patients likely remain to be diagnosed in adult populations of schizophrenia and/or mental retardation.- - - - - - - - - - ranking = 1keywords = hybridization (Clic here for more details about this article) |
8/14. Cat-eye syndrome with different marker chromosomes in a mother and daughter.Except for atypical eye findings in the daughter, a mother and daughter with bisatellited marker chromosomes had abnormalities consistent with cat-eye syndrome. The mother's marker chromosome (mar number 1) is derived from one 22 and another acrocentric, possibly also a 22; the daughter's marker (mar number 2) may be an iso-dicentric, inv-dup (22) derivative of mar number 1. The mother has a tertiary trisomy translocation chromosome composed of at least one and perhaps two copies of 22pter q11.2, whereas the daughter clearly has a secondary trisomy 22pter q11.2 isochromosome, confirming this region as a cause of cat-eye syndrome. Results of hybridization using a unique sequence probe localized to 22q11 are consistent with the interpretation that both ends of both marker chromosomes are derived from 22.- - - - - - - - - - ranking = 1keywords = hybridization (Clic here for more details about this article) |
9/14. Interstitial duplication of proximal 22q: phenotypic overlap with cat eye syndrome.We describe a child with downslanting palpebral fissures, preauricular malfunctions, congenital heart defect (total anomalous pulmonary venous return), unilateral absence of a kidney, and developmental delay with an apparent interstitial duplication of proximal 22q. Fluorescent in situ hybridization (FISH) analysis showed duplication of the IGLC locus, and C-banding of the duplicated region was negative. The duplication appears to involve 22q11.2-q12. Although the child has neither colobomas nor microphthalmia, he shows phenotypic overlap with the cat eye syndrome, which is caused by a supernumerary bisatellited chromosome arising from inverted duplication of the short arm and proximal long arm of chromosome 22. Further molecular studies of this patient should help to define the regions responsible for the manifestations of cat eye syndrome.- - - - - - - - - - ranking = 1keywords = hybridization (Clic here for more details about this article) |
10/14. trisomy 22 and facioauriculovertebral (Goldenhar) sequence.We report on an infant girl born with complete trisomy 22 and left hemifacial microsomia, ear anomaly, and limbal and epibulbar complex choristoma. trisomy 22 was confirmed by prometaphase chromosome analysis and in situ hybridization. This patient extends the list of chromosome abnormalities associated with apparent Golenhar sequence and emphasizes the importance of chromosome analysis in the investigation of patients with this condition. A detailed ophthalmopathological investigation is reported.- - - - - - - - - - ranking = 1keywords = hybridization (Clic here for more details about this article) |
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