According to Healthline, part of the reason that distichiasis can be so dangerous is that the FOX2C gene isn’t just responsible for eyelashes. It’s also a building block of both lymphatic and blood vascular health, so a deviation can have major impact on the body. Recent research suggests that the gene also aids in the formation of veins and the development of the “lungs, eyes, kidneys and urinary tract” while in the womb (per Medline Plus).
Because of this, a majority of people with distichiasis are also affected by lymphedema-distichiasis syndrome (LDS). To get a brief overview, understand that lymph fluid leaks from blood vessels and into the surrounding tissue. In the average human body, this lymph fluid is filtered out through lymphatic vessels. However, if these vessels are not properly developed or have other issues, the fluid cannot be filtered out and instead accumulates in body tissue, leading to pain and swelling.
Worse still, LDS is associated with several cardiac issues, including structural heart abnormalities and an abnormal heart rhythm. Accordingly, an estimated 5% of LDS patients also suffer from congenital heart disease.
