Consanguineous Pakistani families reveal new loci in a complex genetic trait: stuttering

Friday, November 08, 2013 — Poster Session III
10:00 a.m. – 12:00 p.m.	FAES Academic Center (Upper-Level Terrace)	NIDCD	GEN-30

Authors

M.H. Raza
E. Paris
E. Sainz
R. Amjad
S. Riazuddin
D. Drayna

Abstract

Stuttering is a complex genetic disorder which is characterized by involuntary disruption of the flow of speech. Although the twin and adoption studies have demonstrated high heritability of stuttering, incomplete penetrance and the general lack of Mendelian segregation contribute to the limited success of linkage studies and create difficulties for next generation sequencing approaches to this disorder. Linkage and gene finding studies of consanguineous stuttering families previously led to the identification of mutations in the GNPTAB gene associated with stuttering in Pakistani families. We performed additional SNP linkage scans in 32 medium-to-large size consanguineous stuttering families from Pakistan using a ~ 6000 SNP chip from Illumina. Two-point linkage analysis revealed a significant LOD score of 4.23 in PKST77 at chromosome 3q13 and a LOD score of 4.35 at chromosome 16q under recessive mode of inheritance. Multipoint analyses produced LOD scores of 4.92 in PKST77 and 4.42 in PKST58. Multipoint analysis revealed two more loci with LOD scores >3 at chromosome 6p22 in PKST20 and 2q12 in PKST80 under recessive and dominant mode of inheritance respectively. These studies indicate the power of consanguineous families for identifying rare variants of large effect that underlie common complex genetic disorders.