Terminal 10q Deletion Research Articles

Novel copy-number variants in a population-based investigation of classic heterotaxy.

Heterotaxy is a clinically and genetically heterogeneous disorder. We investigated whether screening cases restricted to a classic phenotype would result in the discovery of novel, potentially causal copy-number variants. We identified 77 cases of classic heterotaxy from all live births in New York State during 1998-2005. DNA extracted from each infant's newborn dried blood spot was genotyped with a microarray containing 2.5 million single-nucleotide polymorphisms. Copy-number variants were identified with PennCNV and cnvPartition software. Candidates were selected for follow-up if they were absent in unaffected controls, contained 10 or more consecutive probes, and had minimal overlap with variants published in the Database of Genomic Variants. We identified 20 rare copy-number variants including a deletion of BMP2, which has been linked to laterality disorders in mice but not previously reported in humans. We also identified a large, terminal deletion of 10q and a microdeletion at 1q23.1 involving the MNDA gene; both are rare variants suspected to be associated with heterotaxy. Our findings implicate rare copy-number variants in classic heterotaxy and highlight several candidate gene regions for further investigation. We also demonstrate the efficacy of copy-number variant genotyping in blood spots using microarrays.

Ring chromosome 10: report on two patients and review of the literature

Ring chromosome 10--r(10)--is a rare disorder, with 14 cases reported in the literature, but only two with breakpoint determination by high-resolution techniques. We report here on two patients presenting a ring chromosome 10, studied by G-banding, fluorescent in situ hybridization (FISH), multiplex ligation-dependent probe amplification (MLPA) and SNP-array techniques, in order to investigate ring instability and determine breakpoints. Patient 1 showed a r(10)(p15.3q26.2) with a 7.9 Mb deletion in 10q26.2-q26.2, while patient 2 showed a r(10)(p15.3q26.13) with a 1.0 Mb deletion in 10p15.3 and a 8.8 Mb deletion in 10q26.13-q26.3, both unstable. While patient 1 presented with clinical features usually found in patients with r(10) and terminal 10q deletion, patient 2 presented characteristics so far not described in other patients with r(10), such as Dandy-Walker variant, osteopenia, semi-flexed legs, and dermal pigmentation regions. Our data and the data from literature show that there are no specific clinical findings to define a r(10) syndrome.

Inv dup del(10q): Identification by fluorescence in situ hybridization and array comparative genomic hybridization in a fetus with two concurrent chromosomal rearrangements

ObjectiveTo present molecular cytogenetic characterization of an inverted duplication with terminal deletion of 10q, or inv dup del(10q) in a fetus with two concurrent chromosomal rearrangements. Materials, Methods and ResultsA 39-year-old woman underwent amniocentesis at 20 weeks of gestation because of advanced maternal age. Amniocentesis revealed a der(10) with additional material at the end of the long arm of chromosome 10, a der(9) and a der(22). Parental karyotypes were normal. A de novo unbalanced complex chromosomal rearrangement (CCR) was diagnosed by conventional cytogenetics, but the breakpoints could not be defined. The pregnancy was subsequently terminated, and a malformed fetus was delivered with facial dysmorphism. Postnatal analysis of fetal tissues using spectral karyotyping, fluorescence in situ hybridization, multicolor banding, and array-comparative genomic hybridization identified an inv dup del(10q) with an inverted duplication of 10q25.1→q26.2 and a terminal deletion of 10q26.2→qter, and a balanced reciprocal translocation between chromosomes 9 and 22. Microsatellite analysis determined a paternal origin of the inv dup del(10q). The karyotype of the fetus was 46,XX,t(9;22)(p23;q13),der(10)del(10)(q26.2) dup(10)(q26.2q25.1)dn. ConclusionA de novo inv dup del(10q) can be associated with a concurrent de novo balanced reciprocal translocation and should be differentiated from an unbalanced CCR by molecular cytogenetic techniques.

Autism spectrum disorder with microdeletion 10q26 by subtelomere FISH

Autism spectrum disorder with microdeletion 10q26 by subtelomere FISH Vijay S Tonk1,2, Golder N Wilson11Department of Pediatrics, Texas Tech University Health Sciences Center, Lubbock, TX, USA; 2Departments of Pathology, Obstetrics and Gynecology, Texas Tech University Health Sciences Center, Lubbock, TX, USAAbstract: An 11-year-old female with early feeding problems, mild motor delays, normal speech, subtle facial changes, social difficulties, anxiety and a diagnosis of Asperger disorder was found to have deletion of 10q26.3 by subtelomere fluorescent in situ hybridization (stF) analysis. Our patient and others with 10q26 aneuploidy add this region to 11 other autism susceptibility loci qualified by converging genome linkage/association, high resolution chromosome, and mutation studies in our review. We summarize these loci and the current spectrum of terminal 10q deletion cases.Keywords: autism disorder, Asperger disorder, subtelomere FISH, m analysis, 10q26 deletion, gene changes in autism

Chromosome r(10)(p15.3q26.12) in a newborn child: case report

BackgroundRing chromosome 10 is a rare cytogenetic finding. Of the less than 10 reported cases we have found in the literature, none was characterized using high-resolution microarray analysis. Ring chromosomes are frequently unstable due to sister chromatid exchanges and mitotic failures. When mosaicism is present, the interpretation of genotype-phenotype correlations becomes extremely difficult.ResultsWe report on a newborn girl with growth retardation, microcephaly, congenital heart defects, dysmorphic features and psychomotor retardation. Karyotyping revealed a non-mosaic apparently stable ring chromosome 10 replacing one of the normal homologues in all analyzed metaphases. High-resolution oligonucleotide microarray analysis showed a de novo approximately 12.5 Mb terminal deletion 10q26.12 -> qter and a corresponding 285 kb terminal deletion of 10pter -> p15.3.ConclusionThis case demonstrates that an increased nuchal translucency thickness detected by early ultrasonography should preferably lead to not only QF-PCR for the diagnosis of Down syndrome but also karyotyping. In the future, microarray analysis, which needs further evaluation, might become the method of choice. The clinical phenotype of our patient was in agreement with that of patients with a terminal 10q deletion. For the purpose of genotype-phenotype analysis, there seems to be no need for a "ring syndrome" concept.

Comprehensive molecular cytogenetic investigation of chromosomal abnormalities in human medulloblastoma cell lines and xenograft.

Cell lines and xenografts derived from medulloblastomas are useful tools to investigate the chromosomal changes in these tumors. Here we used G-banding, fluorescence in situ hybridization (FISH), spectral karyotyping (SKY), and comparative genomic hybridization to study 4 medulloblastoma cell lines and 1 xenograft. Cell line D-425 Med had a relatively simple karyotype, with a terminal deletion of 10q and amplification of MYC in double-minutes (dmins). FISH demonstrated that an apparent isochromosome (17q) by routine karyotyping was actually an unbalanced translocation between 2 copies of chromosome 17. Cell line D-556 Med also had a simple near-diploid stemline with an unbalanced 1;13 translocation resulting in a gain of 1q, an isochromosome (17q), and dmins. These findings were initially described using routine G-banded preparations, and FISH showed that the dmins were an amplification of MYC and the i(17q) was an isodicentric 17q chromosome. The other finding was confirmed by FISH, SKY, and comparative genomic hybridization. Cell lines D-721 Med and D-581 Med had complex karyotypic patterns that could be completely characterized only when FISH and SKY were used. Xenograft D-690 Med also had a complex pattern that FISH and SKY were helpful in completely elucidating. Interestingly, balanced reciprocal translocations were seen as well as complicated unbalanced translocations and marker chromosomes. Comparative genomic hybridization demonstrated only a deletion of 10q22-10q24, supporting the idea that despite the complexity of the chromosomal rearrangements, minimal alterations in the overall chromosomal content had occurred. This study demonstrates that routine cytogenetic preparations are adequate to describe chromosomal abnormalities in occasional medulloblastoma samples, but a broader spectrum of molecular cytogenetic methods is required to completely analyze most of these tumor samples.

Terminal deletion of chromosome 10q at band 26.1: Follow-up in an adolescent male with high-output renal failure from congenital obstructive uropathy

We report on the clinical findings in an adolescent male with a de novo terminal deletion of chromosome 10 del(10)(q26.1). This young man is one of the oldest known patients reported with this condition. His condition is compared with that of 11 reported cases of de novo terminal deletion of 10q at band 26. Individuals with chromosome 10q26 deletion have some findings and medical complications in common. Our patient has chronic renal failure due to urinary tract obstruction from posterior urethral valves. Similar anomalies have been reported in cases of 10q26 deletion, suggesting a careful renal/urinary tract evaluation should be completed in individuals with this condition.

The partial monosomy 10q syndrome: report on two patients and review of the developmental data

Two patients, a boy and a girl, with growth delay, mental retardation and mild dysmorphism due to a de novo terminal 10q deletion are described. A recognizable facial appearance with a prominent nose and dysplastic ears was present. Specific attention is given to the developmental and behavioural data of the children. A review is made of the psychologic data of the 18 earlier reported surviving cases.