Mucosal manifestation
White cobblestone pattern of small papules
Overgrowth of gums
Usually affects the mouth, esophagus, rectum, vulva, vagina
Oral symptoms  can be diagnosed by a routine dental examination
Other symptoms and their overall prevalence in the affected population:In 80 to 90% of patients
Acrokeratosis verruciformisAcrokeratosis is characterized by several small wart-like and flat-topped bumps that line the skin on typically the hand and feet. Hypermelanotic macule
Patches on the skin that contain excess pigment, they often appear as dark patches in the skin. Pruritus
Itching
Subungual hyperkeratotic fragments
Thickened skin that is often discolored, under nails, on either hands or feet. Palmar pits
Usually red in color, they are pits or depressions in the palms or soles of the hands and feet. In 30 to 79% of patients
Abnormal hair morphology
Acne conglobata
Typically described as cystic acne

Genetics
Mutations in a single gene, ATP2A2, are responsible for the development of Dariers disease. ATP2A2 encodes the SERCA2 protein, which is a calcium pump localized to the membranes of the endoplasmic reticulum (ER) in nearly all cells and the sarcoplasmic reticulum (SR) in muscle cells. The ER is where protein processing and transport begins for proteins targeted for secretion. The SR is a specialized form of ER found in muscle cells that sequesters calcium, the regulated efflux of which into the cytosol stimulates muscle fiber contraction. Calcium acts as a second messenger in many cellular signal transduction pathways. SERCA2 is required for Ca2+ signaling in cells by removing nearly all Ca2+ ions from the cytoplasm and storing them in the ER/SR compartments.
1959–1969
The years between the first set of "sympathy money" agreements in 1959 and the start of the first legal action to be taken against Chisso in 1969 are often called the "ten years of silence". In fact, much activity on the part of the patients and fishermen took place during this period, but nothing had a significant impact on the actions of the company or the coverage of Minamata in the Japanese media. Continued pollution
Despite the almost universal assumption to the contrary, the wastewater treatment facilities installed in December 1959 had no effect on the level of organic mercury being released into the Shiranui Sea. The pollution and the disease it caused continued to spread. The Kumamoto and Kagoshima prefectural governments conducted a joint survey in late 1960 and early 1961 into the level of mercury in the hair of people living around the Shiranui Sea. The results confirmed that organic mercury had spread all around the inland sea and that people were still being poisoned by contaminated fish. Hundreds of people were discovered to have levels greater than 50 ppm of mercury in their hair, the level at which people are likely to experience nerve damage. The highest result recorded was that of a woman from Goshonoura island who had 920 ppm in her sample. The prefectural governments did not publish the results and did nothing in response to these surveys. The participants who had donated hair samples were not informed of their result, even when they requested it.