Which birth defect refers to developmental defects of fingers or toes?

Polydactylism refers to a condition where an individual has extra fingers or toes, which is a specific type of developmental defect affecting the digits. This condition results from a disruption during the early stages of embryonic development when the limbs are forming. Polydactylism can present as fully formed extra digits or additional, smaller, malformed ones. The presence of these extra digits can vary in form and function, presenting different challenges depending on the individual case.

Understanding the context of the other terms is important. Hemangioma refers to a benign tumor made up of blood vessels, typically seen in infants. Hypertrophy involves the enlargement of an organ or a tissue as a result of an increase in the size of its cells, which does not specifically relate to fingers or toes. Meningocele is a type of spina bifida associated with the spinal cord and does not pertain to digit abnormalities either. Thus, polydactylism is the correct term specifically linked to abnormal development of fingers or toes.