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

• Published in: European journal of human genetics : EJHG Vol. 21; no. 4; pp. 455 - 459
• Main Authors: Raca, Gordana, Baas, Becky S, Kirmani, Salman, Laffin, Jennifer J, Jackson, Craig A, Strand, Edythe A, Jakielski, Kathy J, Shriberg, Lawrence D
• Format: Journal Article
• Language: English
• Published: England Nature Publishing Group 01.04.2013
• Subjects: Acoustics; Apraxias - diagnosis; Apraxias - genetics; Child; Children; Chromosome 16; Chromosome deletion; Chromosomes; Chromosomes, Human, Pair 16 - genetics; Cognitive ability; Comparative Genomic Hybridization; Forkhead Transcription Factors - genetics; Foxp2 protein; Genomes; genomics; Genotype & phenotype; Humans; Hybridization analysis; Intellectual disabilities; Language; Linguistics; Mutation; Pediatrics; Pedigree; Phenotypes; Repetition; Schizophrenia; Sequence Deletion; Sound; Speech; Speech disorders; Standard scores; Studies; Syndrome; United States > US
• ISSN: 1018-4813; 1476-5438
• DOI: 10.1038/ejhg.2012.165

We report clinical findings that extend the phenotype of the ~550 kb 16p11.2 microdeletion syndrome to include a rare, severe, and persistent pediatric speech sound disorder termed Childhood Apraxia of Speech (CAS). CAS is the speech disorder identified in a multigenerational pedigree ('KE') in which half of the members have a mutation in FOXP2 that co-segregates with CAS, oromotor apraxia, and low scores on a nonword repetition task. Each of the two patients in the current report completed a 2-h assessment protocol that provided information on their cognitive, language, speech, oral mechanism, motor, and developmental histories and performance. Their histories and standard scores on perceptual and acoustic speech tasks met clinical and research criteria for CAS. Array comparative genomic hybridization analyses identified deletions at chromosome 16p11.2 in each patient. These are the first reported cases with well-characterized CAS in the 16p11.2 syndrome literature and the first report of this microdeletion in CAS genetics research. We discuss implications of findings for issues in both literatures.