Nonword Repetition as a Behavioural Marker for Inherited Language Impairment: Evidence From a Twin Study

TLDR

The Children's Nonword Repetition Test was administered to 39 children with persistent language impairment, 13 with resolved impairment, and 79 controls aged 7–9 years, all of whom were twins from a prior genetic study. Both resolved and persistent language‑impaired children performed significantly worse on the CNRep, and twin comparisons revealed a significant heritable component, supporting CNRep as a marker of heritable developmental language impairment.

Abstract

The Children's Nonword Repetition Test (CNRep) was given to 39 children with persistent language impairment (LI), 13 with a history of having received speech‐language therapy (resolved LI), and 79 controls, all aged from 7 to 9 years. The children with LI were twins who had participated in a previous genetic study. Children with resolved LI, as well as those with persistent LI. were significantly impaired on the CNRep. Comparisons of MZ and DZ twins indicated significant heritability of a CNRep deficit. It is concluded that CNRep provides a marker of the phenotype of heritable forms of developmental language impairment.