Of unknown or obscure origin; arising from causes that are not clearly visible or easily determined, especially used in medicine for diseases of uncertain cause.
From Greek 'kryptos' (hidden) + 'genetikos' (relating to origin/birth), a medical term appearing in the early 1900s to classify conditions whose etiology remained mysterious.
Doctors use 'cryptogenetic' when they're basically admitting 'we have no idea why this happened'—it's medical honesty in a single word, and some conditions stayed cryptogenetic for centuries until technology finally revealed their secrets.
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