title: The DYX2 locus and neurochemical signaling genes contribute to speech sound disorder and related neurocognitive domains.
abstract: A major milestone of child development is the acquisition and use of speech and language. Communication disorders, including speech sound disorder (SSD), can impair a child's academic, social and behavioral development. Speech sound disorder is a complex, polygenic trait with a substantial genetic component. However, specific genes that contribute to SSD remain largely unknown. To identify associated genes, we assessed the association of the DYX2 dyslexia risk locus and markers in neurochemical signaling genes (e.g., nicotinic and dopaminergic) with SSD and related endophenotypes. We first performed separate primary associations in two independent samples - Cleveland SSD (210 affected and 257 unaffected individuals in 127 families) and Denver SSD (113 affected individuals and 106 unaffected individuals in 85 families) - and then combined results by meta-analysis. DYX2 markers, specifically those in the 3' untranslated region of DCDC2 (P = 1.43 × 10(-4) ), showed the strongest associations with phonological awareness. We also observed suggestive associations of dopaminergic-related genes ANKK1 (P = 1.02 × 10(-2) ) and DRD2 (P = 9.22 × 10(-3) ) and nicotinic-related genes CHRNA3 (P = 2.51 × 10(-3) ) and BDNF (P = 8.14 × 10(-3) ) with case-control status and articulation. Our results further implicate variation in putative regulatory regions in the DYX2 locus, particularly in DCDC2, influencing language and cognitive traits. The results also support previous studies implicating variation in dopaminergic and nicotinic neural signaling influencing human communication and cognitive development. Our findings expand the literature showing genetic factors (e.g., DYX2) contributing to multiple related, yet distinct neurocognitive domains (e.g., dyslexia, language impairment, and SSD). How these factors interactively yield different neurocognitive and language-related outcomes remains to be elucidated.
authors.affiliation: Department of Genetics, Yale University School of Medicine, New Haven, CT.
authors.forename: J D
authors.initials: JD
authors.lastname: Eicher
authors.forename: C M
authors.initials: CM
authors.lastname: Stein
authors.forename: F
authors.initials: F
authors.lastname: Deng
authors.forename: A A
authors.initials: AA
authors.lastname: Ciesla
authors.forename: N R
authors.initials: NR
authors.lastname: Powers
authors.forename: R
authors.initials: R
authors.lastname: Boada
authors.forename: S D
authors.initials: SD
authors.lastname: Smith
authors.forename: B F
authors.initials: BF
authors.lastname: Pennington
authors.forename: S K
authors.initials: SK
authors.lastname: Iyengar
authors.forename: B A
authors.initials: BA
authors.lastname: Lewis
authors.forename: J R
authors.initials: JR
authors.lastname: Gruen
mesh_terms: D019208:Brain-Derived Neurotrophic Factor / Q000235:genetics; D004410:Dyslexia / Q000235:genetics*; D056426:Genetic Loci; D006801:Humans; D008869:Microtubule-Associated Proteins / Q000235:genetics; D020641:Polymorphism, Single Nucleotide; D017346:Protein Serine-Threonine Kinases / Q000235:genetics; D017448:Receptors, Dopamine D2 / Q000235:genetics; D011978:Receptors, Nicotinic / Q000235:genetics; D012045:Regulatory Sequences, Nucleic Acid / Q000235:genetics*; D066229:Speech Sound Disorder / Q000235:genetics*
chemical_list: D019208:Brain-Derived Neurotrophic Factor; D008869:Microtubule-Associated Proteins; D017346:Protein Serine-Threonine Kinases; D017448:Receptors, Dopamine D2; D011978:Receptors, Nicotinic; C510451:DCDC2 protein, human; C581293:DRD2 protein, human; C489948:ANKK1 protein, human
keywords: DCDC2; DYX2; dopaminergic; nicotinic; speech sound disorder