Hemangiomas are common types of birthmarks that appear as benign growths of blood vessels. They often present as red, raised lesions on or under a baby’s skin, sometimes referred to as “strawberry marks” due to their appearance. These vascular growths typically become noticeable within the first few days or weeks after birth.
Are Hemangiomas Inherited?
Infantile hemangiomas are generally not inherited in a predictable manner. Most cases are considered sporadic, meaning they occur randomly without a clear family history. While rare instances of hemangiomas running in families occur, a specific genetic cause for their typical inheritance has not been identified.
What Causes Hemangiomas?
The precise cause of hemangioma development is not yet fully understood. Current theories suggest they arise from an abnormal proliferation of endothelial cells, which are the cells lining blood vessels. This process may be influenced by imbalances in certain growth factors, such as Vascular Endothelial Growth Factor (VEGF) and basic Fibroblast Growth Factor (bFGF), which are often found at elevated levels in actively growing hemangiomas.
Another hypothesis involves a localized response to low oxygen levels, or hypoxia, during fetal development, which can trigger an increase in Hypoxia-Inducible Factor-1α (HIF-1α). This can promote the formation of new blood vessels. Hemangiomas are not caused by anything parents did or did not do during pregnancy. They are more frequently observed in premature infants, babies with low birth weight, females, and those from multiple gestations.
Hemangiomas and Genetic Syndromes
While most hemangiomas are not directly inherited, they can occasionally be a feature of certain rare, inherited genetic syndromes. In these situations, the hemangioma is a manifestation of an underlying genetic condition, rather than being an inherited condition itself. One such example is PHACE syndrome, an acronym for Posterior fossa malformations, Hemangioma, Arterial anomalies, Cardiac defects, and Eye abnormalities. Children with PHACE syndrome often present with large hemangiomas on the face, head, or neck, alongside these other developmental issues.
Another rare condition is GLUT1 deficiency syndrome, a genetic disorder impacting brain metabolism. Hemangiomas linked to this syndrome are characterized by the presence of Glucose Transporter 1 (GLUT1), a protein normally found in red blood cells and certain barrier tissues, a distinctive marker for infantile hemangiomas.
What to Expect and When to Seek Medical Advice
Most infantile hemangiomas follow a predictable course of development. They undergo a period of rapid growth, known as the proliferative phase, typically during the first few months of life. Following this, they enter a slower shrinking phase, called involution, which can take several years. Many hemangiomas resolve on their own, often leaving minimal or no residual trace.
While many hemangiomas are harmless and resolve without intervention, seek medical advice in specific situations: Consult a doctor if the hemangioma is growing rapidly or developing an ulcer. Medical evaluation is also important if the hemangioma is located near the eyes, mouth, or airway, as it can potentially interfere with vision, feeding, or breathing. Other reasons to seek advice include:
- Pain
- Bleeding
- Infection
- Multiple hemangiomas
- A very large hemangioma, which could indicate internal involvement or an underlying syndrome.