African Families Provide New Avenues for Genetic Research
By Dennis Drayna, Ph.D.
Studies of several remarkable families in West Africa have reinforced evidence for genetic factors in some cases of stuttering, and these families are giving us opportunities for research aimed at understanding these factors.
These families live in the Republic of Cameroon, and were originally discovered due to the efforts of the Speak Clear Association of Cameroon (SCAC), one of the leading stuttering self-help organizations in Africa. Led by Mr. Joseph Lukong, Founder and Coordinator General , SCAC has reached out to stutterers across the many diverse regions of Cameroon, and helped coordinate therapy training and practice in that country, with the aid of stuttering programs from both Europe and the United States.
In the course of SCAC's outreach activities, they became aware of several large families in which almost half of all family members stutter beyond young childhood. SCAC then contacted researchers at the National Institutes of Health, in Bethesda, Maryland, regarding these families, which sparked the interest of researchers there. Over the past few years, these families have been carefully documented, and the stuttering that occurs has been shown to be typical of stuttering worldwide. Importantly, the affected individuals in these families do not appear to have any other symptoms or disorders beyond stuttering, making them especially helpful for genetic studies.
Two families have been carefully studied so far. One family consists of roughly 100 individuals in three generations, while the other has 48 members, also in three generations. In these two families there are a remarkable 60 individuals who stutter.
The rare occurrence of these families presents remarkable opportunities for research. We don't yet know if the gene or genes responsible for stuttering in these families cause stuttering in other populations, but we're making progress finding these genes. If and when we find them, we hope they'll tell us important things about the cause of stuttering in general.
Stuttering therapy might be significantly improved if these underlying causes of stuttering were known.