GENETICS OF STUTTERING

Stuttering is characterized by frequent repetition or lengthening of sounds, syllables words, hesitations pauses that disrupt the rhythmic flow speech. It may be accompanied movements face and/or other parts body coincide in time with repetitions, prolongations, speech flow. The prevalence stuttering ranges from 0.3% to 5.6%. Usually for 80%-90% patients starts gradually when children are 2-7 years old. Longitudinal research shows 65% -85% recover. rate heritability about 70%, indicating almost one third disorder caused environmental factors. Currently four genes have been identified involved intracellular metabolism: GNPTAB, GNPTG, NAGPA and AP4E1. single nucleotide synonymous missense mutations exons these genes. Different people affected can carry different sets mutant variants ‒ several. effect on neurobiological processes human brain development remains unknown. So far it has only discovered occurs due lysosomal dysfunction, which adversely affects organization neurofilaments neural networks. contribution cumulatively 20%. There were also 9 candidate (FADS2, PLXNA4, CTNNA3, ARNT2, EYA2, PCSK5, SLC24A3, FMN1 ADARB2) 7 regions 6 chromosomes (2p, 3p, 3q, 12q, 14q, 15q 16q) reliably linked this disorder.
 Further successful genetic studies needed improve our understanding treatment long-enigmatic disorder.