It is considered the most common form of syndromic hearing loss and accounts for upwards of 10% of hereditary deafness.
There is an autosomal recessive pattern inheritance, although this appears complex with most patients being compound heterozygotes. Variations in one gene (SLC26A4) which encodes for the protein pendrin, is found in ~50% of patients with this syndrome although multiple other genes (e.g. FOXI1, KCJN10) have been implicated .
Inner ear malformations are an invariable finding in Pendred syndrome. The most commonly described features are the following :
- modiolus deficiency
- vestibule enlargement
- vestibular aqueduct enlargement: see large vestibular aqueduct syndrome
- absent interscalar septum
Other associated malformations include:
- cochlear dysplasia/hypoplasia or Mondini malformation: common but not a constant feature
History and etymology
It was first described by Vaughan Pendred (1869–1946) in 1896 .