Hoge prevalentie van de ziekte van Rendu-Osler-Weber in de Afro-Caribische bevolking van de Nederlandse Antillen: een familieonderzoek

To determine the prevalence of hereditary haemorrhagic telangiectasia (HHT) in the Afro-Caribbean population of the Netherlands Antilles, to detect patients with pulmonary arteriovenous malformations (pulmonary AVMs) and to identify the causal mutations, by means of family screening.

Design

Screening of first-degree relatives of 23 patients with HHT.

Method

A total of 219 persons over 12 years of age with a first-degree relative with HHT were screened by means of a clinical history and physical examination. The diagnosis was based on the new diagnostic Curaçao criteria. A chest X-ray together with transcutaneous oximetry or the measurement of arterial oxygen pressure was used to detect pulmonary AVMs. The exons of endoglin and activin receptor-like kinase-1 were sequenced.

Results

HHT was diagnosed in 112 patients (51), with a point prevalence of 1 in 1331 inhabitants of Curaçao and Bonaire, aged over 12 years. The diagnosis was uncertain in 27 of the family members. Epistaxis was present in 98 and telangiectasis in 99. Facial telangiectasis was relatively rare due to cutaneous pigmentation. Pulmonary AVMs were found in 28, with serious – mainly neurological – complications in 48. Three haplotypes were found with two known mutations of endoglin and one unknown mutation. One of the known mutations also occurs in a Dutch family and it is likely that a colonist introduced this mutation to the rapidly expanding slave population several centuries ago.

Conclusion

The point prevalence of HHT in the Afro-Caribbean population of Curaçao and Bonaire was the highest known in the world. This is of importance for health-care in the Netherlands in regions where many emigrated Antilleans live. Pulmonary AVMs occurred frequently and caused serious complications.