Mutation status and immunoglobulin gene rearrangements in patients from northwest and central region of Spain with chronic lymphocytic leukemia

The aim of this study was to investigate the frequency and mutation status of the immunoglobulin heavy variable chain (IGHV) in a cohort of 224 patients from northwest and central region of Spain diagnosed with chronic lymphocytic leukemia (CLL), and to correlate it with cytogenetic abnormalities, overall survival (OS) and time to first treatment (TTFT). 125 patients had mutated IGHV, while 99 had unmutated IGHV. The most frequently used IGHV family was IGHV3, followed by IGHV1 and IGHV4. The regions IGHV3-30, IGHV1-69, IGHV3-23, and IGHV4-34 were the most commonly used. Only 3.1% of the patients belonged to the subfamily IGHV3-21 and we failed to demonstrate a worse clinical outcome in this subgroup. The IGHV4 family appeared more frequently with mutated pattern, similar to IGHV3-23 and IGHV3-74. By contrast, IGHV1-69 was expressed at a higher frequency in unmutated CLL patients. All the cases from IGHV3-11 and almost all from IGHV5-51 subfamily belonged to the group of unmutated CLL.

Identification of a novel recurrent gain on 20q13 in chronic lymphocytic leukemia by array CGH and gene expression profiling

BACKGROUND

The presence of genetic changes is a hallmark of chronic lymphocytic leukemia (CLL). The most common cytogenetic abnormalities with independent prognostic significance in CLL are 13q14, ATM and TP53 deletions and trisomy 12. However, CLL displays a great genetic and biological heterogeneity. The aim of this study was to analyze the genomic imbalances in CLL cytogenetic subsets from both genomic and gene expression perspectives to identify new recurrent alterations.

PATIENTS AND METHODS

The genomic imbalances and expression levels of 67 patients were analyzed. The novel recurrent abnormalities detected with bacterial artificial chromosome array were confirmed by FISH and oligonucleotide microarrays. In all cases, gene expression profiling was assessed.

RESULTS

Copy number alterations were identified in 75% of cases. Overall, the results confirmed FISH studies for the regions frequently involved in CLL and also defined a new recurrent gain on chromosome 20q13.12, in 19% (13/67) of the CLL patients. Oligonucleotide expression correlated with the regions of loss or gain of genomic material, suggesting that the changes in gene expression are related to alterations in copy number.

CONCLUSION

Our study demonstrates the presence of a recurrent gain in 20q13.12 associated with overexpression of the genes located in this region, in CLL cytogenetic subgroups.

[Cerebral infarct as a presentation of a hereditary defect of type II C protein]

The case of a 50 year-old patient with a cerebral infarct related to a deficit in type II C protein is described. The patient showed no other vascular risk factor and the cardiological study, which included a transthoracic and a transoesophagic echogram ruled out the presence of embologenic cardiopathy. A family study detected the presence of a deficit of C protein in 6 of the 8 sons and in the patient's sister who had a deep vein thrombosis at the age of 54. A hereditary deficiency in C protein was confirmed. We consider it necessary to perform hypercoagulability studies which include the determination of C protein in patients under 55 years of age with cerebral infarcts of unknown cause, especially when there is a family history of thrombosis.

Blood group polymorphisms and geography in the Sierra de Gredos, Spain

The present research is designed to contribute to our knowledge of the influence of geography on the genetic population structure in the Sierra de Gredos (central Spain). This mountain range separates two distinct areas: the Tormes-Alberche valley in the north and the Tiétar valley in the south. Unrelated blood donors (226), whose 4 grandparents were born in the study area, were tested for blood group markers (A1A2BO, RH, MNSs, Kell, P, and Lewis). R matrix analysis in relation to other Spanish populations agrees reasonably well with the cluster analysis of the Prevosti distance matrix using the UPGMA algorithm. Comparisons suggest a certain degree of genetic variation between the populations of these two valleys. The Sierra de Gredos can thus be considered a biological barrier limiting the gene flow between the valleys.

Serum protein polymorphisms (HP, TF-, GC- and PI subtypes) in two mountain communities of Sierra de Gredos (central Spain)

The genetic variation of four highly polymorphic serum proteins, haptoglobin (HP), transferrin (TF), group-specific component (GC) and alpha-1-antitrypsin (PI) was examined in two representative samples of the autochthonous populations living on either slope of Sierra de Gredos in central Spain. The genetic markers studied do not provide any evidence that the mountain chain has contributed to the maintenance of a genetic differentiation between the two populations. The allele frequency distributions in these Gredos samples are discussed in relation to the variability of these markers in the Iberian Peninsula populations.