Loss of p19Arf in a Rag1(-/-) B-cell precursor population initiates acute B-lymphoblastic leukemia.

In human B-acute lymphoblastic leukemia (B-ALL), RAG1-induced genomic alterations are important for disease progression. However, given that biallelic loss of the RAG1 locus is observed in a subset of cases, RAG1's role in the development of B-ALL remains unclear. We chose a p19Arf(-/-)Rag1(-/-) mouse model to confirm the previously published results concerning the contribution of CDKN2A (p19ARF /INK4a) and RAG1 copy number alterations in precursor B cells to the initiation and/or progression to B-acute lymphoblastic leukemia (B-ALL).

A 24-Mb deletion in 14q in a girl with corpus callosum hypoplasia.

Interstitial deletions of 14q including band 14q31 are uncommon. We report on a 3 year-old Tunisian girl who had a de novo interstitial deletion of the long arm of chromosome 14. The molecular cytogenetic study has identified the deletion as a del(14)(q24.

Five years' experience of preimplantation genetic diagnosis in the Parisian Center: outcome of the first 441 started cycles.

Objective: To investigate the evolution of techniques and strategies and to evaluate the results of preimplantation genetic diagnosis (PGD) from January 2000 to December 2004 in chromosomal, monogenic and mitochondrial DNA disorders treated at our institution.

Design: Retrospective study.

Setting: Single French Parisian PGD center.

[Preimplantation genetic diagnosis (PGD): results from a Parisian center].

Objective: To report the results of preimplantation genetic diagnosis (PGD) cycles performed in our unit from 2000 to 2004. Materials and methods. One hundred and seventy-one couples were enrolled in the PGD program over this period.