Report of a bi-allelic truncating germline mutation in TP53.

The TP53 gene is fundamental to genomic integrity, cell cycle regulation, and apoptosis; it is the most commonly mutated gene in human cancer. Heterozygous germline mutations cause the autosomal dominant cancer predisposition syndrome, Li-Fraumeni Syndrome. Homozygous germline TP53 mutations in humans are rare. We report an infant from a consanguineous family who presented with synchronous malignancies. Remarkably, he carries a homozygous germline TP53 mutation (NM_000546.4:c.52delA), predicted to cause protein truncation. The family history is consistent with Li-Fraumeni syndrome.