Familial spontaneous pneumothorax and lung cysts due to a Folliculin exon 10 mutation.

Approximately 10% of patients who have a spontaneous pneumothorax have a positive family history. In 1977, Birt, Hogg and Dube (BHD) described a genodermatosis characterised by benign tumours of the hair follicle that has been associated with renal neoplasms and spontaneous pneumothorax. The BHD locus is located on chromosome 17p11.2 and is now known to be due to heterozygous germline mutations in the Folliculin gene. We report three generations of an English family who suffered spontaneous pneumothoraces in the absence of other features of the BHD syndrome and were found to have lung cysts. In addition, we report an antenatal diagnosis (34 weeks gestation) of lung cysts in one affected family member. Genetic analysis in the family has revealed a unique deletion mutation (c. 1537 del-C) involving exon 10. To our knowledge, this mutation has not been previously described and there is no previous report of antenatal detection of the pulmonary abnormality in BHD syndrome.