Tarsal kink syndrome is a rare congenital malformation of the tarsus that causes entropion characterized by blepharospasm and absence of an upper eyelid fold that may lead to corneal ulceration caused by the folded edge of the upper tarsus or the inturned eyelashes if not corrected by surgery. The disease is Monarch Disease Ontology id MONDO_0020462 (tarsal kink syndrome).