To study the occurrence of congenital aural atresia in patients with a deletion of the long arm of chromosome 18 (18q- deletion or de Grouchy syndrome).
Study Design and Patients
This retrospective study presents an overview of the otologic findings in 33 Dutch and Belgian patients with a deletion of 18q.
Materials and Methods
Detailed information on otorhinolaryngological findings was obtained from otorhinolaryngologists and audiologic centers. Data about medical and developmental history and phenotype were collected from physical examination by a clinical geneticist, by interviewing parents, and by reviewing medical and developmental records. Determination of deletion breakpoints was established by routine karyotyping, prometaphase studies, and/or fluorescence in-situ hybridization (FISH).
Twenty out of 33 patients (61%) with a deletion 18q had congenital aural atresia (CAA) ranging from narrow external auditory canals to meatal atresia type IIB. Fifteen patients (45%) had conductive hearing impairment (range: 30dB–70dB). Twelve of these 15 patients (80%) received hearing aids, which resulted in improved hearing but not in speech development. CAA was found only in patients with a distal deletion of 18q (including band 18q22.3 or 18q23) and not in patients with more proximal 18q deletions.
In patients with narrow ear canals or meatal atresia and unexplained mental retardation, chromosomal analysis is indicated. If de Grouchy syndrome is diagnosed in a young patient, auditory examination and surveillance are highly recommended.