Those with these types of dysfluencies will exhibit the afore mentioned repetitions about once every 10 sentencesMistiming and stuttering are common ways that developmental dysfluency manifests itself. When a child mistimes, they prolong a certain letter/syllable in the word they are saying, thereby taking much longer for their sentence to be said. Pauses or blocking are another side effect relating to developmental dysfluency. This is when one inserts a silent interval within the word. Revision is similar to this but is the halting completely, mid-flow of a sentence and taking the thought in a different direction. There is evidence to show that this may not only be an issue of speech motor areas but also the auditory cortex. In a MEG study by Beal et al. they found that adults with "persistent developmental stuttering" or PDS, had slower cortical timing than those who spoke completely fluent. This shows us something is wrong in their auditory motor integration. As far as the underlying ailments behind stuttering, It is not well known whether this side effect has to do with "errors in linguistic planning" or issues with "access or retrieval of linguistic elements" and it could very well involve both issues.On occasion, children will go beyond the normal dysfluency patterns. Instances like the previously mentioned example indicate that the child is learning to use language. In contrast, children with stuttering disorder, will likely repeat sounds or one-syllable words three or more times. They may also prolong sounds for two or more seconds.
Mutations on the GNPTAB, GNPTG, and NAGPA have been found to disrupt the signal that directs enzymes to target locations in the brain and cause stuttering in vocal and linguistic processes. Cluttering
Cluttering (Tachyphemia) is a fluency disorder that can co-occur with stuttering but may also occur individually. When someone is experiencing cluttering disorder their conversation segments may be perceived as too fast, too irregular or both. Other symptoms may include stuttering, language or phonological errors, and attention deficits. It may result from disorganized speech planning or being unsure of what to say. Both cluttering and stuttering are forms of fluency disorders that develop beyond the key years of about ages 2–6. During these ages, dysfluency is mainly just considered to be developmental dysfluency. Cluttering, unlike stuttering, can be distinguished by little to no physical structure, little to no secondary behaviors, decreased awareness of speech problems and the aforementioned typical dysfluencies such as revisions and interjections. Both stuttering and cluttering both have a genetic component. About 1/3 of those who stutter will also clutter which can prove even more difficult to overcome with Speech therapy. A consequence of cluttering is individuals may not be willing to attempt to repair breakdowns in communication which may result in less effective social integration and interactions that can lead to a sense of isolation, anxiety, and depression. Differences between disorders and developmental dysfluency
There are several warning signs of speech delays that are not considered developmentally normal.