Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Microdeletion”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 415 records · Page 23Linked to original sources
PubMed2002

Microdeletions of a Y-specific marker, Yfm1, and implications for a role in spermatogenesis.

We have detected deletions of a Y-specific microsatellite marker, Yfm1, located on the Y chromosome (Yq) within interval 6 and near the DAZ (deleted in azoospermia) genes, in 9/89 oligospermic and 17/68 azoospermic Japanese men. No Yfm1 deletions were detected in the 150 normal fertile males examined as controls. Yfm1 deletions in the oligo- and azoospermic males were associated with other deletions that removed entire DAZ genes in those infertile men. These deletions indicated that all Yfm1 loci are located within azoospermia factor c (AZFc) in interval 6 on the long arm of the Y chromosome. Mapping Yfm1 on the Y chromosome using the draft sequence of the human genome revealed that at least three Yfm1 loci are located within about 25-30 kbp of the DAZ genes. Moreover, the Yfm1 marker showed the least number of copies in Japanese males derived from a Y chromosomal lineage called haplotype II, defined by having the Y Alu polymorphism (YAP) insertion. Males from this haplotype II lineage are known from our previous studies to have lower spermatogenic abilities, with higher rates of oligo- and azoospermia than other haplotypes. The least number of Yfm1 loci, whose copy number may correspond to that of the DAZ genes, may be a risk factor predisposing an individual to azoospermia or oligospermia.

Alu Elements↗
PubMed2006

Lack of FMR3 expression in a male with non-syndromic mental retardation and a microdeletion immediately distal to FRAXE CCG repeat.

FRAXE fragile site associated mental retardation (FRAXE MR) belongs to a group of non-syndromic X-linked mental retardation. Two genes, FMR2 and FMR3 (likely a non-coding RNA) are transcribed from the FRAXE CpG island in the opposite directions. While the contribution of the FMR2 gene to FRAXE MR has been demonstrated, the role of the FMR3 gene is not known. We have screened 441 Brazilian mentally handicapped males for CCG repeat expansions in the FMR2 gene and identified a boy with a mutation (c.-414_-357del58) immediately distal to the FRAXE CCG repeat. We have established a skin fibroblast cell line from this patient and tested expression of both FMR2 and FMR3 genes. Reverse transcriptase PCR studies on the FMR2 and FMR3 genes showed that only the FMR3 gene transcription was abolished, suggesting a possible causal relationship between the lack of FMR3 expression and mental retardation in this patient. In the literature, there have been few deletions described near the FRAXE CCG repeat, but none was followed with expression studies. This is the first study showing missing expression in the FMR3 gene with normal FMR2 transcription leading to FRAXE mutation-likely phenotype. The FMR3 gene is likely a non-coding RNA gene. So far all individuals with FRAXE CCG repeat expansions and cytogenetically detectable FRAXE fragile site have both FMR2 and FMR3 gene expression abolished. Although the function of the FMR3 gene is not known, our present study together with previous studies on FRAXE MR suggest that it may play role in the processes underpinning normal learning and memory.

Adolescent↗
PubMed2004

A newly identified chromosomal microdeletion of the rapsyn gene causes a congenital myasthenic syndrome.

The objective is mutation analysis of the RAPSN gene in a patient with sporadic congenital myasthenic syndrome (CMS). Mutations in various genes encoding proteins expressed at the neuromuscular junction may cause CMS. Most mutations affect the epsilon subunit gene of the acetylcholine receptor (AChR) leading to endplate AChR deficiency. Recently, mutations in the RAPSN gene have been identified in several CMS patients with AChR deficiency. In most patients, RAPSN N88K was identified, either homozygously or heteroallelic to a second missense mutation. A sporadic CMS patient from Germany was analyzed for RAPSN mutations by RFLP, long-range PCR and sequence analysis. Clinically, the patient presents with an early onset CMS, associated with arthrogryposis multiplex congenita, recurrent episodes of respiratory insufficiency provoked by infections, and a moderate general weakness, responsive to anticholinesterase treatment. The mutation RAPSN N88K was found heterozygously to a large deletion of about 4.5 kb disrupting the RAPSN gene. Interestingly, an Alu-mediated unequal homologous recombination may have caused the deletion. We hypothesize that numerous interspersed Alu elements may predispose the RAPSN locus for genetic rearrangements.

Child, Preschool↗
PubMed1997

Clinical implications and possible association of malposition of the branch pulmonary arteries with DiGeorge syndrome and microdeletion of chromosomal region 22q11.

We describe a series of 10 patients with malposition of the branch pulmonary arteries (4 patients with crossing [crossed pulmonary arteries] and 6 patients without crossing), 2 of whom had a short main pulmonary artery segment that resulted in iatrogenic right pulmonary artery stenosis after pulmonary artery band placement. DiGeorge syndrome was seen in 5 patients and 4 had microscopic deletion of chromosomal region 22q11.

Adolescent↗
PubMed2003

Detection by fluorescence in situ hybridization of microdeletions at 1p36 in lymphomas, unidentified on cytogenetic analysis.

The chromosomal band 1p36 exhibits frequent loss of heterozygosity in a variety of human malignancies, suggesting the presence of an as yet unidentified tumor suppressor gene. The faint terminal subbands often make cytogenetic analysis of 1p36 particularly difficult. Small deletions at this locus may therefore escape detection on analysis by conventional cytogenetics, a hypothesis that we have explored using fluorescence in situ hybridization (FISH) in malignant lymphoma. The study cohort consisted of 20 cases of lymphoma of various subtypes without any 1p abnormality on G-banded karyotyping. FISH was performed using a human chromosome 1 paint and a bacterial artificial chromosome probe RP4-755G5 localizing to 1p36.33, the most telomeric subband of 1p36. Tumors demonstrating 1p36.33 deletions were additionally analyzed by FISH using a second probe from the proximal 1p36.1 subband, to further define the breakpoint. Eight cases of follicular lymphoma (FL), 5 diffuse large B-cell lymphomas (DLBCL), 2 Hodgkin disease, 2 B-cell small lymphocytic lymphomas, 2 T-cell lymphomas, and 1 marginal zone lymphoma were analyzed. FISH identified deletions at 1p36.33 in 5 of the 20 cases: 3 DLBCL and 2 FL. FISH is considerably more sensitive for identifying lymphoma genetic alterations than conventional cytogenetics. Deletion of the distal part of the 1p36 may be a much more common aberration than previously recognized in lymphoma.

Adolescent↗