International Journal of Clinical Pediatrics, ISSN 1927-1255 print, 1927-1263 online, Open Access
Article copyright, the authors; Journal compilation copyright, Int J Clin Pediatr and Elmer Press Inc
Journal website http://www.theijcp.org

Original Article

Volume 4, Number 1, March 2015, pages 121-126

GJB2 Gene Testing, Etiologic Diagnosis and Genetic Counseling in Romanian Persons With Prelingual Hearing Loss

Figures

Figure 1.
Figure 1. Detection of c.35delG mutation. (A) PCR amplification of DNA using normal and common primers for GJB2 and β-actin primers. (B) PCR amplification of DNA using mutant and common primers for GJB2 and β-actin primers. Lane A01: pUC18/HaeIII marker; lane A02: homozygous 35delG positive control; lane A03: heterozygous c.35delG positive control; lanes A04 to A06: wild type DNA samples; lane A07: homozygous c.35delG DNA sample; lane A08: wild type DNA sample; lanes A09 to A10: heterozygous c.35delG DNA samples; lane A11: homozygous c.35delG DNA sample; lane A12: negative control (a sample to which no DNA was added during the PCR).
Figure 2.
Figure 2. Sequences of GJB2 gene fragments of patients (A-D). Sequencing with forward (left) and reverse (right) primers. Mutations are highlighted with arrows.

Tables

Table 1. Clinical Manifestations of the c.35delG Homozygous Individuals With HL
 
No. of cases (N = 46)Age of onsetDegree of hearing impairmentPrognosis
42PrelingualProfoundStable
2PrelingualSevereStable
1PrelingualModerateStable
1PrelingualMildStable

 

Table 2. List of Identified Mutations After the Sequencing of the GJB2 Identified in the Hearing Impaired Romanian Children
 
GenotypeStateNo. of cases (N = 21)Mode of inheritanceDeafness degree
?: unidentified responsible gene for recessive HL other than DFNB1 (GJB2 and GJB6); SP: sporadic case; AR: autosomal recessive.
W24X/W24XHomozygote3SP; ARProfound
W24X /?Heterozygote2SP; ARSevere
-23+1G>A/- 23+1G>AHomozygote3SP; ARProfound
R127H/?Heterozygote2SP; ARMild
35delG/W24XCompound heterozygote6SP; ARProfound
35delG/?Heterozygote5SP; ARProfound