The underlying mechanism is not well understood.

The hypothesis that embryonic uptake of folate might be impaired by circulating maternal folate-receptor autoantibodies presents a biologically plausible mechanism for the pathogenesis of folate-responsive neural-tube defects. Even though authors needed further studies to verify their results, data are limited.3 One factor that could donate to the limited study of this question may be the complex complexity of the assays in the original report, which included the use of folate receptors purified from human being placental tissue. Moreover, adjustments were designed to the assay in follow-up work from the same laboratory..

A mole with central dark branches Melanomas that arise in pre-existing moles may initially alter the pigment network within the central region and extra the borders. Case presentation Over a three-month period, a 45-year-old girl noted progressive darkening of a longstanding mole, measuring 6 mm in diameter, on the dorsum of her right foot . Dermoscopy demonstrated an asymmetrical mole with an irregular pigment network with regional variation in intensity.