A common cognitive, psychiatric, and dysmorphic phenotype in carriers of NRXN1 deletion.

Deletions in the 2p16.3 region that includes the neurexin (NRXN1) gene are associated with intellectual disability and various psychiatric disorders, in particular, autism and schizophrenia. We present three unrelated patients, two adults and one child, in whom we identified an intragenic 2p16.

Chromosomal bands affected by acute oil exposure and DNA repair errors.

Background: In a previous study, we showed that individuals who had participated in oil clean-up tasks after the wreckage of the Prestige presented an increase of structural chromosomal alterations two years after the acute exposure had occurred. Other studies have also reported the presence of DNA damage during acute oil exposure, but little is known about the long term persistence of chromosomal alterations, which can be considered as a marker of cancer risk.

Objectives: We analyzed whether the breakpoints involved in chromosomal damage can help to assess the risk of cancer as well as to investigate their possible association with DNA repair efficiency.

Novel UBE3A mutations causing Angelman syndrome: different parental origin for single nucleotide changes and multiple nucleotide deletions or insertions.

Angelman syndrome (AS) is a genetic disorder caused by a deficiency of UBE3A imprinted gene expression from the maternal chromosome 15. In 10% of AS cases the genetic cause is a mutation affecting the maternal copy of the UBE3A gene. In two large Spanish series of clinically stringently selected and nonstringently selected patients, we have identified 11 pathological mutations--eight of them novel mutations--and 14 sequence changes considered polymorphic variants.

Does polysomy of chromosome 17 have a role in ERBB2 and topoisomerase IIalpha expression? Gene, mRNA and protein expression: a comprehensive analysis.

Objectives: ERBB2 is an oncogene with prognostic and predictive value. Topoisomerase IIalpha is an enzyme encoding close to the ERBB2 oncogene, that represents a molecular target for anthracyclines. An indirect mechanism of increasing ERBB2 and topoisomerase IIalpha gene copy number is chromosome 17 polysomy.

Imprinting center analysis in Prader-Willi and Angelman syndrome patients with typical and atypical phenotypes.

Prader-Willi syndrome (PWS) and Angelman syndrome (AS) are genetic disorders caused by a deficiency of imprinted gene expression from the paternal or maternal chromosome 15, respectively. This deficiency is due to the deletion of the 15q11-q13 region, parental uniparental disomy of the chromosome 15, or imprinting defect (ID). Mutation of the UBE3A gene causes approximately 10% of AS cases.

Genetic abnormalities and clinical outcome in chronic lymphocytic leukemia.

B-cell chronic lymphocytic leukemia (B-CLL) is the most common leukemia in the elderly population. Under conventional cytogenetic (CC) analysis, approximately 50% of CLL cases show clonal aberrations. Using fluorescent in situ hybridization (FISH), the percentage of patients with abnormalities rises to almost 80%, the most frequent being 13q14, ATM, and TP53 deletions and trisomy 12.

Genetic diagnosis by comparative genomic hybridization in adult de novo acute myelocytic leukemia.

A total of 127 adult de novo acute myelocytic leukemia (AML) patients were analyzed by comparative genomic hybridization (CGH) at diagnosis. Conventional cytogenetic analysis (CCA) showed a normal karyotype in 45 cases and an abnormal karyotype in 56 cases; in the remaining cases, CCA either failed to yield sufficient metaphase cells (19/26) or was not done (7/26). Abnormal CGH profiles were identified in 39 patients (30.