Renal manifestations of tuberous sclerosis complex: patients' and parents' knowledge and routines for renal follow-up - a questionnaire study.

BACKGROUND: Renal angiomyolipomas (AMLs) are a major clinical feature in patients with tuberous sclerosis complex (TSC). Spontaneous bleeding can be life threatening, and appropriate information and proper surveillance and management are important to limit morbidity and mortality. Because TSC is a rare disease, patients are at risk of suboptimal medical management. Our aim was to investigate patients' and parents' knowledge about renal angiomyolipomas (AMLs) in Tuberous Sclerosis Complex (TSC) and to identify current routines for renal follow-up.

METHODS: A questionnaire survey was initiated by the French Reference Centre on TSC. It was distributed in France through university hospitals and the patients' association (2009-2011), and to patients registered by the Norwegian National Centre for Rare Epilepsy-Related Disorders (2013-2014). Contingency tables with Chi-Square test for independence (with Yates Continuity Correction) and Pearson-Chi-Square value were used for correlation statistics.

RESULTS: We included 357 patients (France, n=257; Norway n=100). Most participants knew that TSC is associated with AMLs. However, 42 % did not know about the risk of AMLrelated bleeding, and 37 % had been informed about the risk of bleeding only after the age of 15 years. Furthermore, 14 % did not know whether they themselves or their child had AMLs. Patients had less knowledge than parents. Medical consultations and patient associations were the main sources of information. Among 30 % of patients, renal imaging was not received at all, or not conducted every 1-3 years, as recommended by current guidelines. Regular imaging was more frequent in patients with AMLs < 15 years, than in patients with AMLs ≥ 15 years. Ultrasound was the most frequently used imaging modality.

CONCLUSIONS: Knowledge of renal AML in TSC patients and their parents was lower than expected, and follow-up by renal imaging was suboptimal for a substantial proportion of patients. Patients and parents should be informed about the risk and symptoms of renal bleeding, at the latest when the patient is 15 years. Monitoring the growth of AMLs should be standardized to comply with guidelines. Transition between adolescence and adulthood is a high-risk period and ensuring appropriate follow-up at this time is particularly important.