Diagnostics (Sep 2021)

When Familial Hearing Loss Means Genetic Heterogeneity: A Model Case Report

  • Camille Cenni,
  • Luke Mansard,
  • Catherine Blanchet,
  • David Baux,
  • Christel Vaché,
  • Corinne Baudoin,
  • Mélodie Moclyn,
  • Valérie Faugère,
  • Michel Mondain,
  • Eric Jeziorski,
  • Anne-Françoise Roux,
  • Marjolaine Willems

DOI
https://doi.org/10.3390/diagnostics11091636
Journal volume & issue
Vol. 11, no. 9
p. 1636

Abstract

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We describe a family with both hearing loss (HL) and thrombocytopenia, caused by pathogenic variants in three genes. The proband was a child with neonatal thrombocytopenia, childhood-onset HL, hyper-laxity and severe myopia. The child’s mother (and some of her relatives) presented with moderate thrombocytopenia and adulthood-onset HL. The child’s father (and some of his relatives) presented with adult-onset HL. An HL panel analysis, completed by whole exome sequencing, was performed in this complex family. We identified three pathogenic variants in three different genes: MYH9, MYO7A and ACTG1. The thrombocytopenia in the child and her mother is explained by the MYH9 variant. The post-lingual HL in the paternal branch is explained by the MYO7A variant, absent in the proband, while the congenital HL of the child is explained by a de novo ACTG1 variant. This family, in which HL segregates, illustrates that multiple genetic conditions coexist in individuals and make patient care more complex than expected.

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