congenital syphilis (MONDO_0005714, a Monarch Disease Ontology id) is a life-threatening bacterial infection of the newborn caused by Treponema pallidum. It is transmitted to the infant from a mother with syphilis through the placenta during pregnancy. Signs and symptoms include irritability, fever, failure to thrive, saddle nose, cutaneous rash, and pneumonia. Also known as: MTCT of syphilis, mother-to-child transmission of syphilis.