A newborn with hereditary haemorrhagic telangiectasia and an unusually severe phenotype

Hereditary haemorrhagic telangiectasia (HHT), associated with arteriovenous malformations, is a genetic disease of the vascular system with a frequency of approx. 1:10,000. Genetic diagnosis serves to identify individuals at risk of developing the disease and is a useful tool for genetic counselling purposes. Questions under study: Here we report on a child presenting severe arteriovenous malformations leading to heart failure. Her mother and grandmother present fewer symptoms of hereditary haemorrhagic telangiectasia. In this study we identify the cause of HHT in the family. Methods: Clinical examination, PCR, DNA sequencing, quantitative PCR, Southern blot, x-ray, ultrasound, cardiac catheterisation and angiocardiography. Results: Initially the sequence variant in c.392C>T in the endoglin gene was detected in the grandmother, but not in other affected family members. Further analyses revealed a deletion of exon 1 of endoglin, segregating with the phenotype. Conclusions: This report points out the need for careful evaluation of molecular genetic findings, particularly in diseases with highly variable phenotype.