Grammar Clinical Marker Yields Substantial Heritability for Language Impairments in 16-Year-Old Twins

TY - JOUR

T1 - Grammar Clinical Marker Yields Substantial Heritability for Language Impairments in 16-Year-Old Twins

AU - Dale, Philip S.

AU - Rice, Mabel L

AU - Rimfeld, Kaili

AU - Hayiou-Thomas, Marianna E

N1 - © 2017 American Speech-Language-Hearing Association. This is an author-produced version of the published paper. Uploaded in accordance with the publisher’s self-archiving policy. Further copying may not be permitted; contact the publisher for details

PY - 2018/1/5

Y1 - 2018/1/5

N2 - Purpose: There is a need for well-defined language phenotypes suitable for adolescents in twin studies and other large-scale research projects. Rice, Hoffman, and Wexler (2009) have developed a grammatical judgment measure as a clinical marker of language impairment, which has an extended developmental range to adolescence.Method: We conducted the first twin analysis, along with associated phenotypic analyses of validity, of an abridged, 20-item version of this grammatical judgment measure (GJ-20), based on telephone administration using prerecorded stimuli to 405 pairs of 16-year-olds (148 monozygotic and 257 dizygotic) drawn from the Twins Early Development Study (Haworth, Davis, & Plomin, 2012).Results: The distribution of scores is markedly skewed negatively, as expected for a potential clinical marker. Low performance on GJ-20 is associated with lower maternal education, reported learning disability (age 7 years), and low scores on language tests administered via the Twins Early Development Study (age 16 years) as well as General Certificate of Secondary Education English and Math examination performance (age 16 years). Liability threshold estimates for the genetic influence on low performance on GJ-20 are substantial, ranging from 36% with a lowest 10% criterion to 74% for a lowest 5% criterion.Conclusions: The heritability of GJ-20 scores, especially at more extreme cutoffs, along with the score distribution and association with other indicators of language impairments, provides additional evidence for the potential value of this measure as a clinical marker of specific language impairment.

AB - Purpose: There is a need for well-defined language phenotypes suitable for adolescents in twin studies and other large-scale research projects. Rice, Hoffman, and Wexler (2009) have developed a grammatical judgment measure as a clinical marker of language impairment, which has an extended developmental range to adolescence.Method: We conducted the first twin analysis, along with associated phenotypic analyses of validity, of an abridged, 20-item version of this grammatical judgment measure (GJ-20), based on telephone administration using prerecorded stimuli to 405 pairs of 16-year-olds (148 monozygotic and 257 dizygotic) drawn from the Twins Early Development Study (Haworth, Davis, & Plomin, 2012).Results: The distribution of scores is markedly skewed negatively, as expected for a potential clinical marker. Low performance on GJ-20 is associated with lower maternal education, reported learning disability (age 7 years), and low scores on language tests administered via the Twins Early Development Study (age 16 years) as well as General Certificate of Secondary Education English and Math examination performance (age 16 years). Liability threshold estimates for the genetic influence on low performance on GJ-20 are substantial, ranging from 36% with a lowest 10% criterion to 74% for a lowest 5% criterion.Conclusions: The heritability of GJ-20 scores, especially at more extreme cutoffs, along with the score distribution and association with other indicators of language impairments, provides additional evidence for the potential value of this measure as a clinical marker of specific language impairment.

KW - Journal Article

U2 - 10.1044/2017_JSLHR-L-16-0364

DO - 10.1044/2017_JSLHR-L-16-0364

M3 - Article

C2 - 29305597

SN - 1558-9102

SP - 1

EP - 13

JO - Journal of speech, language, and hearing research : JSLHR

JF - Journal of speech, language, and hearing research : JSLHR

ER -