Prevalence and Phenotype of Childhood Apraxia of Speech in Youth With Galactosemia

Abstract

Purpose-We address the hypothesis that the severe and persistent speech disorder reported in persons with galactosemia meets contemporary diagnostic criteria for Childhood Apraxia of Speech (CAS). A positive finding for CAS in this rare metabolic disorder has the potential to impact treatment of persons with galactosemia and inform explanatory perspectives on CAS in neurological, neurodevelopmental, and idiopathic contexts.Method-Thirty-three youth with galactosemia and significant prior or persistent speech sound disorder were assessed in their homes in 17 states. Participants completed a protocol yielding information on their cognitive, structural, sensorimotor, language, speech, prosody, and voice status and function.Results-Eight of the 33 participants (24%) met contemporary diagnostic criteria for CAS. Two participants, one of whom was among the 8 with CAS, met criteria for ataxic or hyperkinetic dysarthria. Group-wise findings for the remaining 24 participants are consistent with a classification category termed Motor Speech Disorder-Not Otherwise Specified (MSD-NOS; Shriberg, Fourakis, et al., in press-a).Conclusion-We estimate the prevalence of CAS in galactosemia at 18 per hundred, 180 times the estimated risk for idiopathic CAS. Findings support the need to study risk factors for the high occurrence of motor speech disorders in galactosemia, despite early compliant dietary management. Keywords apraxia; dyspraxia; genetics; motor speech disorder; speech sound disorder Consistent trends in the sparse literature on galactosemia and communicative disorders indicate high occurrence of significant and persistent speech sound disorder (SSD) in persons with galactosemia, with most reported speech findings consistent with developmental verbal dyspraxia. As recommended by the American Speech-LanguageHearing Association (ASHA, 2007), we hereafter reference apraxia of speech in children as Childhood Apraxia of Speech (CAS). The following three sections, respectively, review cognitive, language, and speech findings in galactosemia, summarize contemporary research issues in CAS, and describe rationale for the three questions about galactosemia and CAS addressed in this study. NIH-PA Author ManuscriptNIH-PA Author Manuscript NIH-PA Author Manuscript Galactosemia DescriptionGalactosemia is an autosomal recessive metabolic disorder estimated to occur in 1 in 53,000 infants in the United States (National Newborn Screening and Genetics Resource Center; Newborn Screening and Genetic Testing Symposium, 2002). Galactose is one of two sugars that make up the complex milk sugar, lactose. Individuals with galactosemia lack or have insufficient amounts of the galactose-1-phosphate uridylyltransferase enzyme needed to break down galactose, resulting in a toxic build-up of galactose -1-phosphate in the red blood cells. The most common genotype for galactosemia, Q188R/Q188R, was found in 62% of 107 cases of galactosemia described in Elsas, Langley, Paulk, Hjelm, and Dembure (1995). Individuals homozygous for galactosemia ...

Childhood Apraxia of Speech (CAS) in two patients with 16p11.2 microdeletion syndrome

“…42 In one recent study of 33 youth with classic galactosemia and a history of speech disorders, CAS was documented in 8 (24.2%) of patients. 43 Such findings suggest that patients with CAS should be considered for aCGH testing to look for 16p11.2 deletions or other genomic CNVs associated with increased risk for speech and language impairments. Similarly, referrals for speech assessment for undiagnosed CAS may be appropriate for children with 16p11.2 deletions and significant speech sound disorder.…”

Speech characteristics of 8-year-old children: Findings from a prospective population study

“…Increasingly however, it has been recognised that difficulties can persist beyond the early years and into older childhood. This is evident from recent studies that have investigated samples of children with persistent speech disorder (PSD) (Clark, Harris, Jollef, Price & Neville, 2010;Goozee, Murdoch, Ozanne, Cheng, Hill & Gibbon, 2007;McGrath, Hutaff-Lee, Scott, Boada & Shriberg, 2008;Peterson, Pennington, Shriberg & Boada, 2009;Shriberg, Potter & Strand, 2011). Yet population data on the speech characteristics of children beyond the age when speech acquisition is generally considered to be complete is lacking.…”

“…Moreover, studies of PSD have typically used small clinical samples rather than reference to a normative dataset. These small clinical samples were identified either through referral to speechlanguage pathology services Pascoe, Stackhouse & Wells, 2005), identification of speech sound disorder when younger (Goozee et al, 2007;Kenney, Barac-Cikoja, Finnegan, Jeffries & Ludlow, 2006;Lewis, Freebairn, Hansen, Iyengar & Taylor, 2004;Lewis & Freebairn, 1992) or presence of a comorbid condition (Clark et al, 2010;Gibbon, McNeill, Wood & Watson, 2003;Shriberg, Potter & Strand, 2011). Tomblin (2010) highlights the limitations of studies based solely on clinical samples and advocates for the use of population sampling methods.…”

A Diagnostic Marker to Discriminate Childhood Apraxia of Speech From Speech Delay: II. Validity Studies of the Pause Marker

“…The 296 participants whose data appear in Table 1 were from three groups: children and adults suspected to have active or persistent CAS (n = 60), adults meeting Mayo Clinic System (MCS; Shriberg, Potter, & Strand, 2011) criteria for one of two types of adult-onset apraxia of speech (AAS) described later (n = 31), and children meeting the Speech Disorders Classification System (SDCS; Shriberg, Strand, & Mabie, 2017) criteria for SD (see PM I; n = 205).…”