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Purpose To demonstrate that early childhood speech sound disorders (SSD) and later school-age reading, written expression, and spelling skills are influenced by shared endophenotypes that may be in part genetic. Method Children with SSD and their siblings were assessed at early childhood (ages 4–6 years) and followed at school age (7–12 years). The relationship of shared endophenotypes with early childhood SSD and school-age outcomes and the shared genetic influences on these outcomes were examined. Results Structural equation modeling demonstrated that oral motor skills, phonological awareness, phonological memory, vocabulary, and speeded naming have varying influences on reading decoding, spelling, spoken language, and written expression at school age. Genetic linkage studies demonstrated linkage for reading, spelling, and written expression measures to regions on chromosomes 1, 3, 6, and 15 that were previously linked to oral motor skills, articulation, phonological memory, and vocabulary at early childhood testing. Conclusions Endophenotypes predict school-age literacy outcomes over and above that predicted by clinical diagnoses of SSD or language impairment. Findings suggest that these shared endophenotypes and common genetic influences affect early childhood SSD and later school-age reading, spelling, spoken language, and written expression skills. Supplemental Material https://doi.org/10.23641/asha.6170354

Numerous studies have examined genetic influences on developmental problems such as speech sound disorders, language impairment, and reading disability. Disorders such as speech sound disorder (SSD) are often analyzed using their component endophenotypes. Most studies, however, have involved comparisons of twin pairs or siblings of similar age, or have adjusted for age ignoring effects that are peculiar to age-related trajectories for phenotypic change. Such developmental changes in these skills have limited the usefulness of data from parents or siblings who differ substantially in age from the probands. Employing parent-offspring correlation in heritability estimation permits a more precise estimate of the additive component of genetic variance, but different generations have to be measured for the same trait. We report on a smoothing procedure which fits a series of lines that approximate a curve matching the developmental trajectory. This procedure adjusts for changes in measures with age, so that the adjusted values are on a similar scale for children, adolescents, and adults. We apply this method to four measures of phonological memory and articulation in order to estimate their heritability. Repetition of multisyllabic real words showed the best heritability estimate of 45% in this sample. We conclude that differences in measurement scales across the age span can be reconciled through non-linear modeling of the developmental process.

Disorders of articulation or speech-sound disorders (SSD) are common in early childhood. Children with these disorders may be at risk for reading difficulties because they may have poor auditory, phonologic, and verbal memory skills.We sought to characterize the reading and writing readiness of preschool children with SSD and identify factors associated with preliteracy skills. Subjects were 125 children aged 3 to 6 years with moderate to severe SSD; 53% had comorbid language impairment (LI). Reading readiness was measured with the Test of Early Reading Ability-2 (TERA) and writing skills with the Test of Early Written Language-2 (TEWL), which assessed print concept knowledge. Linear regression was used to examine the association between SSD severity and TERA and TEWL scores and analysis of variance to examine the effect of comorbid LI. Performance on a battery of speech and language tests was reduced by way of factor analysis to composites for articulation, narrative, grammar, and word knowledge skills.Early reading and writing scores were significantly lower for children with comorbid LI but were not related to SSD severity once language status was taken into account. Composites for grammar and word knowledge were related to performance on the TERA and TEWL, even after adjusting for Performance IQ. Below average language skills in preschool place a child at risk for deficits in preliteracy skills, which may have implications for the later development of reading disability.Preschool children with SSD and LI may benefit from instruction in preliteracy skills in addition to language therapy.

Purpose This study compared parents with histories of speech sound disorders (SSD) to parents without known histories on measures of speech sound production, phonological processing, language, reading, and spelling. Familial aggregation for speech and language disorders was also examined. Method The participants were 147 parents of children with SSD (58 fathers and 89 mothers) who were directly tested and interviewed for family history of disorders. Results Thirty-six parents (18 mothers and 18 fathers) reported enrollment in speech therapy as children for SSD. Parents with a history of speech therapy obtained lower scores on the Multisyllabic Word Repetition, Nonword Repetition, and Tongue Twister tasks than parents without such histories. These parents also had poorer reading, spelling, and receptive language skills. Parents with histories of SSD and additional language impairments (LI) performed worse than parents with isolated SSD on all measures except Pig Latin and oral motor skills. Familial aggregation for SSD and LI was supported. In addition, the likelihood of SSD in a family member increased by a factor of 1.9 over rates of SSD found in individuals without additional family members with SSD, and the odds of LI increased by a factor of 4.1 over rates of LI found in individuals without additional family members with LI for each additional family member with SSD or LI, respectively. Conclusions The results documented both residual effects in adulthood of childhood SSD and familial aggregation for SSD. These residual difficulties do not appear to affect educational and occupational outcomes.

The purpose of this article is to review recent findings suggesting a genetic susceptibility for speech sound disorders (SSD), the most prevalent communication disorder in early childhood. The importance of genetic studies of SSD and the hypothetical underpinnings of these genetic findings are reviewed, as well as genetic associations of SSD with other language and reading disabilities. The authors propose that many genes contribute to SSD. They further hypothesize that some genes contribute to SSD disorders alone, whereas other genes influence both SSD and other written and spoken language disorders. The authors postulate that underlying common cognitive traits, or endophenotypes, are responsible for shared genetic influences of spoken and written language. They review findings from their genetic linkage study and from the literature to illustrate recent developments in this area. Finally, they discuss challenges for identifying genetic influence on SSD and propose a conceptual framework for study of the genetic basis of SSD.

The goal of this study was to classify children with speech sound disorders (SSD) empirically, using factor analytic techniques. Participants were 3-7-year olds enrolled in speech/language therapy (N = 185). Factor analysis of an extensive battery of speech and language measures provided support for two distinct factors, representing the skill dimensions of articulation/phonology and semantic/syntactic skills. To validate these factors, 38 of the children were followed to school age to re-evaluate speech and language skills and assess reading/spelling achievement. The validity of the two factors was supported by their differential associations with school-age reading and spelling achievement, persistence of SSD, and affection status in family members. A closer relationship of the family member to the proband and male gender predicted higher odds of a disorder. The findings suggest that articulation/phonology and language abilities are at least partially independent in children with SSD and that these constructs have distinct clinical and biological correlates.The reader will develop knowledge about subtypes of speech sound disorders, understand the relationship between early speech sound disorders and later reading and spelling difficulties, and obtain information concerning familial transmission of speech sound disorders.

Purpose: The primary aim of this study was to examine differences in speech/language and written language skills between children with suspected childhood apraxia of speech (CAS) and children with other speech-sound disorders at school age. Method: Ten children (7 males and 3 females) who were clinically diagnosed with CAS (CAS group) were followed from the preschool years (ages 4–6) to school age (ages 8–10) and were compared with children with isolated speech-sound disorders (S group; n =15) and combined speech-sound and language disorders (SL group; n =14). Assessments included measures of articulation, diadochokinetic rates, language, reading, and spelling. Results: At follow-up, 8 of the children with CAS demonstrated improvement in articulation scores, but all 10 continued to have difficulties in syllable sequencing, nonsense word repetition, and language abilities. The children also exhibited comorbid disorders of reading and spelling. Group comparisons revealed that the CAS group was similar to the SL group, but not the S group during the preschool years. By school age, however, the SL group made more positive changes in language skills than the CAS group. Clinical Implications: These findings suggest that the phenotype for CAS changes with age. Language disorders persist in these children despite partial resolution of articulation problems. Children with CAS are also at risk for reading and spelling problems.

Forty-two children (29 boys and 13 girls), ages 3–10 years, were referred from the caseloads of clinical speech-language pathologists for suspected childhood apraxia of speech (CAS). According to results from tests of speech and oral motor skills, 22 children met criteria for CAS, including a severely limited consonant and vowel repertoire, difficulty sequencing syllables, and inconsistent and unusual errors. Family pedigrees for these children were constructed through parent interviews and direct testing of nuclear family members. Familial aggregation for speech-sound and language disorders was demonstrated with 86% reporting at least one nuclear family member affected. Based on parent report, 13 of the 22 children (59%) had at least one affected parent. However, CAS was evident in only two siblings of probands with CAS and two probands with other speech-sound disorders. Based on testing, overall affection rates of speech-sound/language disorders were higher in families of children with CAS than in families of children with other speech-sound disorders. Mothers of children with CAS demonstrated a higher affection rate than mothers of children with other speech-sound disorders. A sex-related threshold model of transmission was also supported with brothers more often affected than sisters for male probands only. If our inclusionary criteria for CAS are valid, these findings support a general verbal trait deficit hypothesis. Learning outcomes (1) As a result of this activity, the participant will understand potential familial risk factors for CAS; (2) will differentiate aggregation for speech-sound and language disorders in families with CAS from families of children who have other speech-sound disorders; (3) will distinguish how familial aggregation differs in families of boys and girls with CAS; (4) will determine how children with CAS differ in severity from those with other speech-sound disorders.

Speech-sound disorder (SSD) is a complex behavioral disorder characterized by speech-sound production errors associated with deficits in articulation, phonological processes, and cognitive linguistic processes. SSD is prevalent in childhood and is comorbid with disorders of language, spelling, and reading disability, or dyslexia. Previous research suggests that developmental problems in domains associated with speech and language acquisition place a child at risk for dyslexia. Recent genetic studies have identified several candidate regions for dyslexia, including one on chromosome 3 segregating in a large Finnish pedigree. To explore common genetic influences on SSD and reading, we examined linkage for several quantitative traits to markers in the pericentrometric region of chromosome 3 in 77 families ascertained through a child with SSD. The quantitative scores measured several processes underlying speech-sound production, including phonological memory, phonological representation, articulation, receptive and expressive vocabulary, and reading decoding and comprehension skills. Model-free linkage analysis was followed by identification of sib pairs with linkage and construction of core shared haplotypes. In our multipoint analyses, measures of phonological memory demonstrated the strongest linkage (marker D3S2465, P =5.6×10 −5 , and marker D3S3716, P =6.8×10 −4 ). Tests for single-word decoding also demonstrated linkage (real word reading: marker D3S2465, P =.004; nonsense word reading: marker D3S1595, P =.005). The minimum shared haplotype in sib pairs with similar trait values spans 4.9 cM and is bounded by markers D3S3049 and D3S3045. Our results suggest that domains common to SSD and dyslexia are pleiotropically influenced by a putative quantitative trait locus on chromosome 3.

Background/Aims: Genetic studies have raised the possibility of common bases for cognitive linguistic disorders such as speech sound disorder (SSD), reading disorder (RD) and language impairment (LI). Thus, some of the same genes may jointly influence cognitive components within and between these three disorders. We examined the plausibility of this theory in a sample of families ascertained on the basis of a child with SSD. Methods: Using the method of generalized estimating equations to solve a bivariate family predictive model we obtained measures of comorbidity and familial aggregation of SSD and LI. We then used two methods of multipoint model-free linkage analysis to evaluate SSD and LI psychometric test measures over a region previously implicated in linkage studies of RD, DYX8 region, 1p34-p36. Results: Bivariate phenotypic analyses show evidence of comorbidity and within family aggregation and coaggregation of SSD and LI. In addition, two regions on chromosome 1 show suggestive evidence of linkage. The first region was previously reported in dyslexia studies. Our maximum linkage signal in this region measured articulation (p = 0.0009) in SSD sibling pairs. The second region is characterized by processes involved in language production, with the maximum linkage signal measuring listening comprehension (p = 0.0019) using all sibling pairs. Conclusion: We conclude that the DYX8 region could bear genes controlling pleiotropic effects on SSD, LI and RD.

Despite a growing body of evidence indicating that speech sound disorder (SSD) has an underlying genetic etiology, researchers have not yet identified specific genes predisposing to this condition. The speech and language deficits associated with SSD are shared with several other disorders, including dyslexia, autism, Prader-Willi Syndrome (PWS), and Angelman’s Syndrome (AS), raising the possibility of gene sharing. Furthermore, we previously demonstrated that dyslexia and SSD share genetic susceptibility loci. The present study assesses the hypothesis that SSD also shares susceptibility loci with autism and PWS. To test this hypothesis, we examined linkage between SSD phenotypes and microsatellite markers on the chromosome 15q14–21 region, which has been associated with autism, PWS/AS, and dyslexia. Using SSD as the phenotype, we replicated linkage to the 15q14 region (P = 0.004). Further modeling revealed that this locus influenced oral-motor function, articulation and phonological memory, and that linkage at D15S118 was potentially influenced by a parent-of-origin effect (LOD score increase from 0.97 to 2.17, P = 0.0633). These results suggest shared genetic determinants in this chromosomal region for SSD, autism, and PWS/AS.