GENOME DATABASES described mutations in all genes, but with each being represented in only limited detail. By con- trast, LSDBs are concerned with just one or a few speciﬁc genes, usually related to a single disease entity.2,3 NEMDBs are repositories documenting the genetic composition of an ethnic group and/or population, and the genetic defects leading to various inherited disorders and their frequencies, calculated on a population-speciﬁc basis.4 These resources have recently emerged, mostly driven by the need to document the varying mutation spec- trum observed for any gene associated with a genetic disorder, among different population and ethnic or religious groups. In general, the NEMDBs available to date can be separated into two subcategories: (1) national genetic databases, which record the existing genetic composition of a population or ethnic group but with limited or no description of mutation frequencies, and (2) national mutation frequency databases, which provide comprehensive information only on inher- ited disorders whose disease-causing mutation spec- trum is well deﬁned.4 A detailed domain analysis of the various NEMDBs presently available has been previously Figure 1. Outline of the Israeli national and ethnic mutation database (NEMDB). The database has three main components: disease summaries (categorised by religious groups); allele frequency search options, available separately in a public or restricted password-protected (Search þ) environment; and genetic laboratories. The database is under the scientiﬁc control of a group of curators under the supervision of the Israeli NEMDB National Coordinator, while a dedicated database development and maintenance team oversees the smooth operation of the Israeli NEMDB. van Baal et al. performed.4 Here, we provide an overview of the different functionalities of the ETHnic and National database Operating Software (ETHNOS) v2.0 software and comparatively describe the various national genetic databases that have resulted from the implementation of this software — namely, the Israeli, Cypriot, Tunisian, Lebanese and Egyptian NEMDBs. These databases were some of the tangible deliverables of the European Commission-funded Euro-Mediterranean Network for Genetic Services (MEDGENET) project. Finally, we demonstrate possible outcomes from the evolution of the NEMDB ﬁeld towards a truly nationwide clinical genetics database, not only for research but also for everyday clinical use. Materials and methods The ETHNOS v2.0 software is built around two different ﬂat-ﬁle database techniques: single ﬂat-ﬁle and indexed multiple ﬂat-ﬁle databases, both of which are tab delimited — ie, ﬁelds separated with a tab — with one record per line and maintained using a custom content management system (CMS). The websites run on PHP (version 4 or higher) and are hosted by the Golden Helix Server (http://www. goldenhelix.org), which operates under Apache 2, PHP 5 with the virtual hosts feature enabled. Database techniques Each NEMDB that derives from this software has its own data folder in the Golden Helix Server and consists of three independent functionalities (see Figure 1): (a) The disease summaries. This option employs the indexed multiple ﬂat-ﬁle database tech- nique. The records can span multiple lines and the text can be any plain text or valid HTML code. A collection of HTML ﬁles is maintained through a straightforward index ﬁle (Figure 2A). The ﬂat-ﬁle database starts with a special line (eg ###jsummariesj) that is simply skipped when reading the database, but is necessary for determining whether the correct ﬁle has been used. The second line is used to 362 # HENRY STEWART PUBLICATIONS 1479–7364. HUMAN GENOMICS. VOL 4. NO 5. 361–368 JUNE 2010