Identification of two heterozygous deafness mutations in SLC26A4 (PDS) in a Chinese family with two siblings

Abstract

Objective: To detect genetic cause of two Chinese siblings (patient 1 and 2) with Pendred syndrome. Design: Patients and their parents underwent clinical and genetic evaluations. To identify genetic mutations, sequencing of SLC26A4 was carried out. Study sample: Two siblings and their parents. Results: Clinical evaluations showed that patient 1 suffered from bilateral postlingual progressive sensorineural hearing loss with enlarged vestibular aqueduct and slight diffuse multinodular goiter with euthyroid, and patient 2 suffered from bilateral prelingual progressive sensorineural hearing loss with enlarged vestibular aqueduct and no goiter with euthyroid. Furthermore, the sequence analysis of SLC26A4 indicated that either of the two siblings presented a compound heterozygote for the c.919A>G mutation in the splice site of intron 7 and for the c.1548insC mutation in exon 14. Their mother was a heterozygous carrier of the splice site mutation in intron 7, and their father was a heterozygous carrier of the insertion mutation in exon 14. Conclusions: Mutation analysis identified a compound heterozygous mutation (c.919A>G/c.1548insC) in SLC26A4 in two Chinese siblings with Pendred syndrome. Also, c.1548insC was first reported in the Chinese population. Although the two siblings from the same family carried the same genotype, they presented different phenotypes.

Key Words::

• Hearing loss
• SLC26A4
• mutation
• Pendred syndrome
• enlarged vestibular aqueduct

Acknowledgements

This work was supported by the grants from the Key Project supported by Medical Science and Technology Development Foundation, Nanjing Department of Health (No. 201108019), the National Natural Science Foundation of China (No. 30973302; No.31171217), Medical Key Talent program of the Health Department of Jiangsu Province (No. RC2007010), and the Priority Academic Program Development of Jiangsu Higher Education Institutions (PAPD).

Declaration of interest: The authors declare no conflict of interest.