Recent advances in the genetics of language impairment

Dianne F Newbury,Simon E Fisher,Anthony P Monaco

doi:10.1186/gm127

Dianne F Newbury, Simon E Fisher + Show 1 more

Open Access

https://doi.org/10.1186/gm127

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Abstract

Specific language impairment (SLI) is defined as an unexpected and persistent impairment in language ability despite adequate opportunity and intelligence and in the absence of any explanatory medical conditions. This condition is highly heritable and affects between 5% and 8% of pre-school children. Over the past few years, investigations have begun to uncover genetic factors that may contribute to susceptibility to language impairment. So far, variants in four specific genes have been associated with spoken language disorders - forkhead box P2 (FOXP2) and contactin-associated protein-like 2 (CNTNAP2) on chromosome7 and calcium-transporting ATPase 2C2 (ATP2C2) and c-MAF inducing protein (CMIP) on chromosome 16. Here, we describe the different ways in which these genes were identified as candidates for language impairment. We discuss how characterization of these genes, and the pathways in which they are involved, may enhance our understanding of language disorders and improve our understanding of the biological foundations of language acquisition.

Highlights

Language is a quintessential human trait that, for the most part, proceeds along a recognized trajectory with minimal explicit instruction [1]
forkhead box P2 (FOXP2) mutations seem to contribute to only a relatively small number of language disorder cases, it seems likely that variations in the genes it controls, such as contactinassociated protein-like 2 (CNTNAP2), may be implicated in common forms of language impairment
The expression of FOXP2 seems to be important for neurological mechanisms rele vant to motor skills, we predict that ATPase 2C2 (ATP2C2) and c-MAF inducing protein (CMIP) are likely to be involved in memory-related circuits

Summary

Introduction

Language is a quintessential human trait that, for the most part, proceeds along a recognized trajectory with minimal explicit instruction [1]. The CNTNAP2 gene has recently been implicated in multiple neurodevelopmental disorders, including Gilles de la Tourette syndrome [58], schizophrenia [59], epilepsy [59,60], autism [57,61,62,63,64,65], ADHD [66] and mental retardation [45] (Table 1) This diverse range of studies provides evidence for the disruption of CNTNAP2 by copy number variants (CNVs), gross chromosomal rearrangements and mutations as well as association with common variants. The fact that neither ATP2C2 nor CMIP have been identified as downstream targets of FOXP2 suggests that the eventual combination of information from converging routes of investigation will enable the characterization of over lapping and interacting neurological systems that serve the acquisition of language

Conclusions

Pinker S: The Language Instinct

Findings

67. The SLI Consortium