Human Phenotype Ontology id HP_0000954 (Single transverse palmar crease) can be described as follows. The distal and proximal transverse palmar creases are merged into a single transverse palmar crease. Also known as: Simian crease, Simian creases, Simian line, Single flexion crease, Single palmar crease, Single palmar creases, Single transverse palmar creases, Transverse palmar crease.