Cardiac rhabdomyoma: a rare feature of Birt-Hogg-Dubé syndrome.

Birt-Hogg-Dubé syndrome (BHDS) is a rare autosomal disorder, primarily characterised in adults by cutaneous features, pulmonary cysts that predispose to spontaneous pneumothorax and renal tumours. The syndrome is caused by pathogenic variants in the FLCN tumour suppressor gene, which plays a role in the mammalian target of rapamycin (mTOR) signalling pathway. We present the case of a newborn infant diagnosed with BHDS, who died of sudden cardiac death due to complications from cardiac rhabdomyoma. This is only the second reported case of such an association. Both cases were initially misdiagnosed with tuberous sclerosis complex, highlighting the diagnostic challenges. We discuss this differential diagnosis and suggest that cardiac rhabdomyomas, although rare, may be associated with BHDS and potentially life threatening. Therefore, we recommend cardiac screening in newborns at risk.