Correlation between genotype and phenotype in patients with bi-allelic SLC26A4 mutations.

[pendred syndrome]

Mutation of SLC 26 A 4 is the most common cause of prelingual hearing loss in East Asia . Patients with SLC 26 A 4 mutations have variable phenotypes ranging from non-syndromic hearing loss to Pendred syndrome . Here , we analyzed the correlation between genotype and various inner ear phenotypes and found a possible underlying mechanism . This study included 111 patients with bi -allelic SLC 26 A 4 mutations who had bilateral enlarged vestibular aqueduct (EVA ) and hearing loss . p .H 723 R (61 %), c .919 -2 A >G (24 %), and p .T 410 M (4 %) were the most common mutations in Korean patients with EVAs . Residual hearing in patients with c .919 -2 A >G or p .T 410 M mutations was better than that of patients with p .H 723 R homozygous mutations . Interestingly , quantitative polymerase chain reaction showed normal pendrin transcript (6 -17 % of normal levels ) was produced from patients with c .919 -2 A >G homozygous mutations . Surface expression ratio of pendrin and residual anion exchange activity were higher in cells transfected with p .T 410 M in comparison to cells transfected with p .H 723 R . These results suggest that there is a correlation between degree of residual hearing and the SLC 26 A 4 genotype commonly found in the East Asian population .

Diseases
Validation

Diseases presenting "hearing loss" symptom

22q11.2 deletion syndrome

achondroplasia

adrenomyeloneuropathy

alexander disease

benign recurrent intrahepatic cholestasis

canavan disease

cohen syndrome

congenital toxoplasmosis

dentinogenesis imperfecta

fabry disease

familial mediterranean fever

heparin-induced thrombocytopenia

hirschsprung disease

holt-oram syndrome

homocystinuria without methylmalonic aciduria

hydrocephalus with stenosis of the aqueduct of sylvius

kabuki syndrome

kallmann syndrome

neonatal adrenoleukodystrophy

pendred syndrome

von hippel-lindau disease

wolf-hirschhorn syndrome

This symptom has already been validated