Nance-Horan syndrome pedigree due to a novel microdeletion and skewed X chromosome inactivation.

Background: Nance-Horan syndrome (NHS) is a rare and often overlooked X-linked dominant disorder characterized by dense congenital cataracts, dental abnormalities, and mental retardation. The majority of NHS variations include frameshift mutations, nonsense mutations, microdeletions, and insertions.

Methods: Copy number variation sequencing was performed to determine the microdeletion.