METHODOLOGY
This study was approved by Institutional Ethical Committee and informed
consent was obtained from all participants. Sixty four probands were
recruited from various schools, hospitals and speech therapy clinics and
clinically diagnosed for stuttering by speech pathologist using
Stuttering Severity Instrument 3(SSI-3)34. A
structured interview using questionnaire was conducted to elicit
demogenetic details (table A1). More details on recruitment of the
probands is given in our previous paper6.
Eight milliliters of blood was collected by venipuncture into labelled
EDTA coated vacutainers (Beckon and Dickinson Co., USA). Genomic DNA was
isolated using Phenol-Chloroform extraction method35.