Recommendations for the clinical interpretation of genetic variants and presentation of results to patients with inherited bleeding disorders. A UK Haemophilia Centre Doctors' Organisation Good Practice Paper.

This paper sets out good practice for clinicians involved in interpreting variant reports for patients with inherited bleeding disorders. It is aimed primarily at doctors, nurses and allied healthcare professionals who may not have had specific training in genetic testing methodology or reporting. It deals with uncertainty in classification of variant pathogenicity and the handling of incidental findings.

Diagnosis and management of von Willebrand disease in the United Kingdom.

The UK treatment strategy for von Willebrand disease (VWD) is based on consensus guidelines produced by the United Kingdom Haemophilia Centre Doctors' Organization (UKHCDO) relating to the diagnosis and management of VWD. Selection of therapeutic products suitable for treatment of this complex inherited bleeding disorder is based on the observed response. Desmopressin (DDAVP), an analog of vasopressin, is the recommended treatment in individuals who respond to this drug on trial infusion. DDAVP clearly has no effect in type 3 VWD but may have variable clinical effect in individuals with other subtypes or may be contraindicated in some cases. In patients where DDAVP treatment is unsuitable, replacement factor concentrate containing von Willebrand factor (VWF) is the recommended alternative. Relevant concentrates are available for all patients in the United Kingdom, and treatment is administered by a network of 67 hemophilia treatment centers that also provide specialist care for individuals diagnosed with VWD. Patients diagnosed with the condition are registered on a national inherited bleeding disorder database administered by the UKHCDO on behalf of the Department of Health to aid in service planning and commissioning. Genetic testing is employed in the United Kingdom in certain situations, which is also performed in accordance with current UKHCDO guidelines.

EMQN best practice guidelines for the molecular genetic diagnosis of hereditary hemochromatosis (HH).

Molecular genetic testing for hereditary hemochromatosis (HH) is recognized as a reference test to confirm the diagnosis of suspected HH or to predict its risk. The vast majority (typically >90%) of patients with clinically characterized HH are homozygous for the p.C282Y variant in the HFE gene, referred to as HFE-related HH. Since 1996, HFE genotyping was implemented in diagnostic algorithms for suspected HH, allowing its early diagnosis and prevention. However, the penetrance of disease in p.C282Y homozygotes is incomplete. Hence, homozygosity for p.C282Y is not sufficient to diagnose HH. Neither is p.C282Y homozygosity required for diagnosis as other rare forms of HH exist, generally referred to as non-HFE-related HH. These pose significant challenges when defining criteria for referral, testing protocols, interpretation of test results and reporting practices. We present best practice guidelines for the molecular genetic diagnosis of HH where recommendations are classified, as far as possible, according to the level and strength of evidence. For clarification, the guidelines' recommendations are preceded by a detailed description of the methodology and results obtained with a series of actions taken in order to achieve a wide expert consensus, namely: (i) a survey on the current practices followed by laboratories offering molecular diagnosis of HH; (ii) a systematic literature search focused on some identified controversial topics; (iii) an expert Best Practice Workshop convened to achieve consensus on the practical recommendations included in the guidelines.