423 respondents across more than 10 countries. Here is what the numbers show.
42.1% report exclusively maternal transmission. The maternal-to-paternal ratio is 5.4:1. Only 7.8% report exclusively paternal transmission.
77.4% of respondents who answered this item report significant stressful or traumatic events during childhood (ages 0–18).
94.8% experienced difficulties before receiving appropriate care. 80.9% went through years of odyssey or still have no adequate care. 94.5% never had urinary histamine measured.
68.8% of parent respondents report their children present with similar conditions. 9.7% report a SIDS history in their family or close circle.
These findings support the hypothesis of a Programmed Mast Cell Hyperreactivity Syndrome (PMCHS) — a heritable terrain, transmitted predominantly along the maternal line, amplified by perinatal history and life stress. The term "idiopathic" no longer reflects what the data shows.