Hydrops-ectopic calcification-moth-eaten skeletal dysplasia is a defect in cholesterol biosynthesis.

[6] Hydrops-ectopic calcification-moth-eaten skeletal dysplasia causes the bones in a fetus to develop abnormally.

This leads to a characteristic "moth eaten" appearance of the bones when viewed under an X-ray.

Micromelia, polydactyly and ectopic calcification, or the built up of calcium in the soft tissues of the body, may all occur.

[7] The second defining feature of hydrops-ectopic calcification-moth-eaten skeletal dysplasia is hydrops fetalis.