Lack of association between inherited thrombophilic risk factors and idiopathic sudden sensorineural hearing loss in Italian patients.
OBJECTIVE
We investigated the presence of congenital thrombophilic risk factors in a population of consecutive Italian patients affected by idiopathic sudden sensorineural hearing loss (SSNHL).


METHODS
We investigated 48 patients with idiopathic SSNHL for the presence of congenital thrombophilic risk factors. The factor V Leiden G1691A, the prothrombin G20210A allele, and methylenetetrahydrofolate reductase (MTHFR) C677T genotypes were investigated. Allele frequencies and genotype distribution of all factors found in patients were compared to those of 48 healthy subjects of the same ethnic background by Chi2 and odds-ratio analysis. Odds ratios and 95% confidence intervals were calculated for allele and genotype frequencies of all thrombophilia variants. Statistical significance was accepted with a p value of less than .05. We also performed the following blood tests: hemacytometric analysis including platelet count, prothrombin time, activated partial thromboplastin time, fibrinogen, erythrocyte sedimentation rate, C-reactive protein, protein S, protein C, antithrombin III, and activated protein C resistance.


RESULTS
In our series, we did not find an association between SSNHL and abnormal levels of antithrombin III, protein C, protein S, D-dimer, or fibrinogen; activated protein C resistance; or factor V G1691A, prothrombin G20210A, or MTHFR C677T mutations.


CONCLUSIONS
At present, the few studies regarding genetic polymorphisms of congenital thrombophilic factors in SSNHL are not conclusive. According to our data, factor V G1691A, prothrombin G20210A, and MTHFR C677T variants should be not considered risk factors for SSNHL. Further large prospective studies are needed to provide currently lacking information and to improve our knowledge in the field before we recommend the determination of genetic polymorphism in SSNHL as routine practice.
Cadoni
Gabriella
G
Department of Otorhinolaryngology, Catholic University of the Sacred Heart, Rome, Italy.
Scipione
Simona
S
Rocca
Bianca
B
Agostino
Stefania
S
La Greca
Carmelo
C
Bonvissuto
Davide
D
Paludetti
Gaetano
G
D000293:Adolescent; D000328:Adult; D000368:Aged; D005165:Factor V / Q000235:genetics; D005260:Female; D005500:Follow-Up Studies; D005787:Gene Frequency; D020022:Genetic Predisposition to Disease; D005838:Genotype; D006319:Hearing Loss, Sensorineural / Q000150:complications / Q000453:epidemiology / Q000235:genetics*; D006801:Humans; D015994:Incidence; D007558:Italy / Q000453:epidemiology; D008297:Male; D042965:Methylenetetrahydrofolate Reductase (NADPH2) / Q000235:genetics; D008875:Middle Aged; D011516:Prothrombin / Q000235:genetics; D012307:Risk Factors; D019851:Thrombophilia / Q000150:complications / Q000453:epidemiology / Q000235:genetics*
C095381:factor V Leiden; D005165:Factor V; D011516:Prothrombin; D042965:Methylenetetrahydrofolate Reductase (NADPH2)