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Osteogenesis Imperfecta: the audiological phenotype lacks correlation with the genotype
Freya K R Swinnen1, Paul J Coucke, Anne M De Paepe
1Department of Otorhinolaryngology, Ghent University Hospital, De Pintelaan 185, B-9000 Ghent, Belgium. Freya.Swinnen@UGent.be
Orphanet Journal of Rare Diseases
|December 31, 2011
Summary
Hearing loss in Osteogenesis Imperfecta (OI) exhibits significant intrafamilial variability, even among relatives with similar COL1A1/COL1A2 gene mutations. Other genetic factors likely influence the expression of hearing impairment in OI patients.
Area of Science:
- Genetics
- Otolaryngology
- Connective Tissue Diseases
Background:
- Osteogenesis Imperfecta (OI) is a heritable connective tissue disorder primarily caused by COL1A1/COL1A2 gene mutations.
- Approximately 50% of OI patients experience hearing loss, typically starting as conductive and progressing to mixed hearing loss.
Purpose of the Study:
- To evaluate inter- and intrafamilial variability in hearing loss among Osteogenesis Imperfecta patients.
- To investigate correlations between specific COL1A1/COL1A2 mutations and audiological characteristics.
Main Methods:
- Audiological examination of 184 OI patients (types I, III, IV) with COL1A1/COL1A2 mutations.
- Analysis of a subsample (n=114) aged over 40 or with early-onset hearing loss to assess mutation-specific associations.
Main Results:
- Hearing loss detected in 48.4% of OI patients, with higher prevalence in older individuals.
- Mixed hearing loss was most common (27.5%), followed by sensorineural (12.5%) and conductive (8.4%).
- No significant association found between COL1A1/COL1A2 mutation type and hearing loss characteristics; intrafamilial variability was notable.
Conclusions:
- Hearing loss in OI demonstrates substantial intrafamilial variability.
- The expression of hearing loss in OI is likely influenced by additional genetic modifiers beyond COL1A1/COL1A2 mutations.
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