New light on genetic factors

By Dennis Drayna, Ph.D.alt text
NIDCD

Studies in Pakistan over the past few years have added new impetus?ÿto research on genetic factors in stuttering.?ÿ Research at the?ÿNational Institutes of Health has recently identified a specific?ÿlocation for a gene that seems to be an important contributor to?ÿstuttering in this population.?ÿ Scientists have found that this gene?ÿresides on chromosome 12, which provides a start to identifying the?ÿgene itself.?ÿThese results were recently published in the American?ÿJournal of Human Genetics, a leading scientific journal.

Like elsewhere in the world, stuttering in Pakistan appears to come?ÿfrom both genetic and non-genetic causes.?ÿ Although stuttering does?ÿnot seem to occur at a higher rate in the Pakistani population?ÿoverall, it often occurs in large family clusters. This may be due to?ÿtraditional marriage patterns that have existed in Pakistan for many?ÿgenerations, in which marriage between cousins is considered highly?ÿdesirable.

ƒ??We are fortunate to have wonderful cooperation from the many?ÿPakistani families involved in this study.ƒ?? said Dr. Dennis Drayna, a?ÿleader of the NIH study. ƒ??While we have not yet identified this gene?ÿon chromosome 12, we know where to look, and weƒ??re optimistic that?ÿweƒ??ll see rapid progress in the coming year,ƒ?? said Dr. Drayna.

The work was carried out at the National Institute on Deafness and?ÿOther Communication Disorders, in collaboration with scientists at?ÿthe University of Chicago and the Centre of Excellence in Molecular?ÿBiology at the University of the Punjab, in Lahore, Pakistan.

Finding a gene alteration that causes stuttering is of great?ÿinterest, as it may help shed light on the underlying causes?ÿinvolved. Of particular interest will be what the gene codes for, and?ÿhow it acts, both in stutterers and in normally fluent individuals.

ƒ??Even finding one gene is unlikely to be the whole story.ƒ?? cautioned?ÿDr. Drayna, who emphasized that itƒ??s likely there will be other?ÿgenes, as well as non-genetic factors involved in stuttering. ƒ??But?ÿweƒ??d be delighted to have one gene to study to get us started on?ÿunderstanding the bigger picture.ƒ?? he said.

Reference:
Riaz, N., Steinberg S., Ahmad, J., Pluzhnikov, A., Raizuddin, S.,?ÿ
Cox, N., and D. Drayna. Genomewide significant linkage to stuttering?ÿ
on chromosome 12. American Journal of Human Genetics. 76:647-651 (2005)