High-Resolution Array CGH Analysis Identifies Regional Deletions and Amplifications of Chromosome 8 in Uveal Melanoma.

PURPOSE: Monosomy 3 (M3) and abnormalities of chromosome 8 associate with poor prognosis in uveal melanomas (UM). Although M3 has been the subject of more in-depth studies, none have intensively focused on chromosome 8. To elucidate the potential role of chromosome 8 abnormalities, array comparative genomic hybridization (aCGH) was performed on primary UM. METHODS: A specifically-designed custom high-resolution array was developed focusing on changes most implicated in UM. Probes for chromosome 8 had a mean spacing of 2.3 kb while chromosomes infrequently affected had a mean spacing of 36.6 kb. A series of 75 UM, including one formalin-fixed paraffin sample were analyzed, and where possible control DNA extracted from the patient's own peripheral blood was used. RESULTS: The most common copy number abnormalities were chromosome 8 (75%) and M3 (51%), with M3 and gain of the long arm of chromosome 8 (8q+) associated in 41% of cases. Also identified were partial deletions of chromosome 3 (3%) and regional 8q+ (23%), and the intensive coverage of chromosome 8 revealed small focal deletions and amplifications affecting both arms. The most significant predictor of prognosis was M3/8q+ having a hazard ratio of 10.1 (P < 0.0001). CONCLUSIONS: Neither 8p deletion nor focal changes affecting chromosome 8 were linked to outcome. The most significant indicator was M3/8q, and multiple 8q+ associated with shorter survival. Studying UM with this technology provides a powerful robust tool for predicting prognosis while considering other genetic changes, allowing the future incorporation of such data as it becomes clinically significant.

Identification and characterisation of mutations associated with von Willebrand disease in a Turkish patient cohort.

Several cohort studies have investigated the molecular basis of von Willebrand disease (VWD); however, these have mostly focused on European and North American populations. This study aimed to investigate mutation spectrum in 26 index cases (IC) from Turkey diagnosed with all three VWD types, the majority (73%) with parents who were knowingly related. IC were screened for mutations using multiplex ligation-dependent probe amplification and analysis of all von Willebrand factor gene (VWF) exons and exon/intron boundaries. Selected missense mutations were expressed in vitro. Candidate VWF mutations were identified in 25 of 26 IC and included propeptide missense mutations in four IC (two resulting in type 1 and two in recessive 2A), all influencing VWF expression in vitro. Four missense mutations, a nonsense mutation and a small in-frame insertion resulting in type 2A were also identified. Of 15 type 3 VWD IC, 13 were homozygous and two compound heterozygous for 14 candidate mutations predicted to result in lack of expression and two propeptide missense changes. Identification of intronic breakpoints of an exon 17-18 deletion suggested that the mutation resulted from non-homologous end joining. This study provides further insight into the pathogenesis of VWD in a population with a high degree of consanguineous partnerships.