An Internet-based external quality assessment in cytogenetics that audits a laboratory's analytical and interpretative performance.

A novel approach to external quality assessment (EQA) using the Internet mimics the diagnostic situation so that multiple tests can be requested and EQA cases can be 'tailor made' to address a specific chromosome syndrome, disease, or clinical dilemma. The web-based EQA system was trialled on a large UK EQA scheme, UK NEQAS for Clinical Cytogenetics. It has also been used to implement a new Cytogenetics European Quality Assessment scheme, CEQA, set up with the intention of providing laboratories in countries without access to a local EQA scheme the opportunity of participation in EQA.

Maturity-onset diabetes of the young caused by a balanced translocation where the 20q12 break point results in disruption upstream of the coding region of hepatocyte nuclear factor-4alpha (HNF4A) gene.

Monogenic human disorders have been used as paradigms for complex genetic disease and as tools for establishing important insights into mechanisms of gene regulation and transcriptional control. Maturity-onset diabetes of the young (MODY) is a monogenic dominantly inherited form of diabetes that is characterized by defective insulin secretion from the pancreatic beta-cells. A wide variety of mutation types in five different genes have been identified that result in this condition.