Clinical genetics in transition-a comparison of genetic services in Estonia, Finland, and the Netherlands

Genetics has traditionally enabled the reliable diagnosis of patients with rare genetic disorders, thus empowering the key role of today's clinical geneticists in providing healthcare. With the many novel technologies that have expanded the genetic toolkit, genetics is increasingly evolving beyond rare disease diagnostics. When placed in a transition context-like we do here-clinical genetics is likely to become a fully integral part of future healthcare and clinical genetic expertise will be required increasingly outside traditional clinical genetic settings. We explore transition effects on the thinking (culture), organizing (structure), and performing (practice) in clinical genetics, taking genetic healthcare in Estonia, Finland, and the Netherlands as examples. Despite clearly distinct healthcare histories, all three countries have initially implemented genetic healthcare in a rather similar fashion: as a diagnostic tool for predominantly rare congenital diseases, with clinical geneticists as the main providers. Dynamics at different levels, such as emerging technologies, biobanks and data infrastructure, and legislative frameworks, may require development of a new system attuned with the demands and (historic) context of specific countries. Here, we provide an overview of genetic service provisions in Estonia, Finland, and the Netherlands to consider the impact of historic and recent events on prospective developments in genetic healthcare.

The CASPR2 cell adhesion molecule functions as a tumor suppressor gene in glioma

Genomic translocations have been implicated in cancer. In this study, we performed a screen for genetic translocations in gliomas based on exon-level expression profiles. We identified a translocation in the contactin-associated protein-like 2 (CASPR2) gene, encoding a cell adhesion molecule. CASPR2 mRNA was fused to an expressed sequence tag that likely is part of the nuclear receptor coactivator 1 gene. Despite high mRNA expression levels, no CASPR2 fusion protein was detected. In a set of 25 glioblastomas and 22 oligodendrogliomas, mutation analysis identified two additional samples with genetic alterations in the CASPR2 gene and all three identified genetic alterations are likely to reduce CASPR2 protein expression levels. Methylation of the CASPR2 gene was also observed in gliomas and glioma cell lines. CASPR2-overexpressing cells showed decreased proliferation rates, likely because of an increase in apoptosis. Moreover, high CASPR2 mRNA expression level is positively correlated with survival and is an independent prognostic factor. These results indicate that CASPR2 acts as a tumor suppressor gene in glioma.

CNTNAP2 gene dosage variation is associated with schizophrenia and epilepsy

A homozygous mutation of the CNTNAP2 gene has been associated with a syndrome of focal epilepsy, mental retardation, language regression and other neuropsychiatric problems in children of the Old Order Amish community. Here we report genomic rearrangements resulting in haploinsufficiency of the CNTNAP2 gene in association with epilepsy and schizophrenia. Genomic deletions of varying sizes affecting the CNTNAP2 gene were identified in three non-related Caucasian patients. In contrast, we did not observe any dosage variation for this gene in 512 healthy controls. Moreover, this genomic region has not been identified as showing large-scale copy number variation. Our data thus confirm an association of CNTNAP2 to epilepsy outside the Old Order Amish population and suggest that dosage alteration of this gene may lead to a complex phenotype of schizophrenia, epilepsy and cognitive impairment.

Effect of inbreeding on the incidence of retained placenta in Friesian horses1

This study was motivated by the hypothesis that the incidence of retained placenta (RP) in Friesian horses is associated with inbreeding. The objectives were to 1) calculate the inbreeding rate in the total registered Friesian horse population; 2) study the association of the inbreeding coefficient of the foal and the mare with the incidence of RP; and 3) study the heritability of RP in Friesian mares after normal foalings. Data from the total registered Friesian horse population from 1879 to 2000 (52,392 individuals) were collected from the registration files of the Friesian Horse Studbook. In 1999 and 2000, 495 parturitions in 436 mares were studied. From 1979 to 2000, the inbreeding rate of the total population was 1.9% per generation. The regression coefficients for the regression of the incidence of RP on inbreeding coefficients of the foal and the mare were 0.12 +/- 0.052 and -0.016 +/- 0.019, respectively. Mean heritability estimates of RP as a foal trait and as a mare trait were 0.046 +/- 0.088 and 0.105 +/- 0.123, respectively. It was concluded that, in order to avoid a further increase in the incidence of RP in Friesian mares, a decrease in the inbreeding rate by increasing the effective breeding population is required. Furthermore, the findings indicate that the high incidence of RP in Friesian horses is at least partly a result of inbreeding.