Underfolded helix

What it means

Underdevelopment of the helix that either affects the entire helix, or is localized.

Helix folding is highly variable, and the range is illustrated in Figures 29 and 30. To use this term, the affected area must be too long to be considered a Cleft helix. Underdevelopment of part of the helix can lead to the impression that the scaphal area is enlarged.

Rare diseases that can present with this4

The range is how often this sign appears among people diagnosed with each disease — it is not a probability of having any of them. Many of these signs also occur in common, non-rare conditions. A sign on this page is a conversation to have with a clinician, not a conclusion.

Part of the broader category

Also called: Poorly folded helices