A homozygous deletion of a normal variation locus in a patient with hearing loss from non-consanguineous parents

Jeroen Knijnenburg (1) , Saskia a J Lesnik Oberstein (1) , Klemens Frei (2) , Trevor Lucas (2) , Antoinet C J Gijsbers (1) , Claudia a L Ruivenkamp (1) , Hans J Tanke (1) , Karoly Szuhai (1)

1 Department of neurology
2 Medizinische Universität Wien = Medical University of Vienna

International databases with information on copy number variation of the human genome are an important reference for laboratories using high resolution whole genome screening. Genomic deletions or duplications which have been detected in the healthy population and thus marked as normal copy number variants (CNVs) can be filtered out using these databases when searching for pathogenic copy number changes in patients. However, a potential pitfall of this strategy is that reported normal CNVs often do not elicit further investigation, and thus may remain unrecognized when they are present in a (pathogenic) homozygous state. The impact on disease of CNVs in the homozygous state may thus remain undetected and underestimated.

Mots clés: Clinical genetics; Cytogenetics; Genetic screening/counselling; Molecular genetics

Jeroen Knijnenburg, Saskia a J Lesnik Oberstein, Klemens Frei, Trevor Lucas, Antoinet C J Gijsbers, et al.. A homozygous deletion of a normal variation locus in a patient with hearing loss from non-consanguineous parents. Journal of Medical Genetics, 2009, 46 (6), pp.412. ⟨10.1136/jmg.2008.063685⟩. ⟨hal-00552672⟩