Stuttering is a speech disorder long recognized to have a genetic component. Recent linkage studies mapped a susceptibility locus for stuttering to chromosome 12 in 46 highly inbred families ascertained in Pakistan. We report here on linkage studies in 100 families of European descent ascertained in the United States, Sweden, and Israel. These families included 252 individuals exhibiting persistent stuttering, 45 individuals classified as recovered from stuttering, and 19 individuals too young to classify. Primary analyses identified moderate evidence for linkage of the broader diagnosis of "ever stuttered" (including both persistent and recovered stuttering) on chromosome 9 (LOD = 2.3 at 60 cM) and of the narrower diagnosis of persistent stuttering on chromosome 15 (LOD = 1.95 at 23 cM). In contrast, sex-specific evidence for linkage on chromosome 7 at 153 cM in the male-only data subset (LOD = 2.99) and on chromosome 21 at 34 cM in the female-only data subset (LOD = 4.5) met genomewide criteria for significance. Secondary analyses revealed a significant increase in the evidence for linkage on chromosome 12, conditional on the evidence for linkage at chromosome 7, with the location of the increased signal congruent with the previously reported signal in families ascertained in Pakistan. In addition, a region on chromosome 2 (193 cM) showed a significant increase in the evidence for linkage conditional on either chromosome 9 (positive) or chromosome 7 (negative); this chromosome 2 region has been implicated elsewhere in studies on autism, with increased evidence for linkage observed when the sample is restricted to those with delayed onset of phrase speech. Our results support the hypothesis that the genetic component to stuttering has significant sex effects.

This study examines the production and reduction patterns of initial /s/ clusters by Hebrew-speaking children with phonological disorders. Data were collected from 30 children with phonological disorders between the ages of 3;5-5;2. The data were elicited by means of a picture-naming task combined with a sentence completion task. Target words consisted of initial clusters, including #sC and #CC clusters. Results revealed that the percentage of correct productions of /s/+approximant clusters were significantly lower than those of the correct productions of other /s/ clusters. The differences between /s/+approximant clusters and the other /s/ clusters also emerged in the reduction patterns, where clusters from the first group were reduced to C1 but clusters from the second group were reduced to C2. There were no differences in the correct productions between the productions of SSP-violating clusters and the SSP-following clusters.

Objective: The aim of this paper was to describe the error patterns of the dorsal rhotic /ʁ ̞ / in the speech of typically developing Hebrew-speaking children and to examine the prosodic effect (i.e., position in the word and stress pattern) of its production. Method and Participants: The participants included 50 monolingual Hebrew-speaking children aged 2; 6-3; 3 years. The children performed an articulation task in which they were asked to articulate 18 disyllabic words composed of vowel-adjacent rhotics in initial, medial, and final word positions in both stressed and unstressed syllables. Results: The results revealed that dorsal rhotics were produced correctly in 78.7% of the target words. The main error patterns were rhotic deletion and devoicing. There were fewer correct productions in initial word positions than in both medial and final word positions. No stress effect was found. In addition, 76% of the children produced the consonant correctly in over half of their productions. Conclusions: The result demonstrating a higher rate of errors in initial word positions may be due to the relatively late acquisition of the initial onset position in multisyllabic Hebrew words. Alternatively, this finding may result from the greater degree of allophonic variation found in this position. The finding that languages with dorsal rhotics have unique error patterns compared to other rhotics strengthens the evidence that rhotic error patterns are dependent on the rhotics' phonetic characteristics.