Birth defects may result in death, chronic illness or long term disability with a significant impact on individuals, families, health care systems and societies. Many birth defects are also associated with intellectual disability as part of rarer patterns or syndromes and require multidisciplinary care. More than 8000 rare syndromes have been described. Thus although rare these are collectively important conditions. They may have genetic, environmental and multifactorial causes but in 50% of cases the cause is currently unknown. Identifying causes and studying the natural history of multiple anomaly syndromes and rare forms of syndromal or non-syndromal intellectual disabilities guides management or treatment, provides answers for families and healthcare professionals, furthers understanding of normal development through research and may lead to prevention. All of these will have significant health economic benefits and guide commissioning of future services. However, expertise in the study of these conditions is limited to a few experts, in major healthcare centres. In some EU member states the specialty of syndrome diagnosis and management is not well established, there is no specialist training and there are few clinical and laboratory resources. We propose to continue the patient-centred European Reference Network for Rare Malformations and Intellectual Disability, ITHACA, which aims to meet the needs of patients, both diagnosed and undiagnosed. ITHACA works to improve access to diagnostic expertise by utilizing an innovative telehealth approach and guiding quality assured diagnostic testing.