Objectives Marfan’s syndrome (MFS) with an estimated prevalence of 1 in 5–10,000 is an autosomal dominant connective tissue disorder affecting mainly the cardiovascular, ophthalmic and skeletal systems. 75% of Marfan patients have an affected parent. Clinical diagnosis of MFS requires a major criterion in 2 systems and involvement of a third system according to the 1996 Gent criteria. Approximately 70% of patients fulfilling the Gent criteria have a fibrillin 1 gene mutation (FBN1).

Methods A retrospective chart review of 112 referrals to the Northern Ireland Regional Genetics Services for investigation of Marfan’s syndrome was completed. The referral source, fulfilment of the Gent criteria, presence of a family history and alternative diagnosis, in addition to outcome of FBN1 gene analysis if completed were the parameters assessed.

Results 28% of referrals fulfilled the Gent criteria for a clinical diagnosis of MFS. Genetic testing was completed in 42% of these individuals, with FBN1 gene mutation being identified in 54%. A positive family history was present in 74% of these individuals. The most appropriate referrals were from the specialities of neonatology, ophthalmology and cardiology. Those referred with isolated findings such as scoliosis, tall stature, pectus excavatum and learning difficulties were least likely to meet the Gent criteria.

Conclusions The Gent criteria continue to remain the main diagnostic tool for the diagnosis of Marfan syndrome. Marfan genetic analysis is indicated only in complex cases or for predictive testing in individuals with a family history.