Characterization of a mutation commonly associated with persistent stuttering: evidence for a founder mutation

Area of Science:

• Genetics
• Speech disorders
• Molecular biology

Background:

• Stuttering is a speech fluency disorder with high heritability.
• Recent research links stuttering to mutations in the GNPTAB gene.
• The specific Glu1200Lys mutation has been observed in multiple unrelated individuals.

Purpose of the Study:

• To determine if the recurrent Glu1200Lys mutation in GNPTAB arose independently or from a single common ancestor.
• To investigate the origin and age of the Glu1200Lys stuttering-associated mutation.

Main Methods:

• Analysis of haplotype sharing across 12 chromosomes with the Glu1200Lys mutation in eight unrelated individuals.
• Phylogenetic analysis using cladogram construction to trace the mutation's lineage.

Main Results:

• All analyzed chromosomes carrying the Glu1200Lys mutation shared a common haplotype.
• This indicates the mutation is of founder origin, stemming from a single ancestral chromosome.
• The estimated age of the Glu1200Lys founder mutation is approximately 572 generations.

Conclusions:

• The Glu1200Lys mutation in the GNPTAB gene, associated with stuttering, is a founder mutation.
• The findings support a single origin for this mutation, prevalent in stuttering populations.
• Understanding the mutation's origin aids in genetic counseling and research into stuttering etiology.