# Aging Language Trajectories in Premutation Carrier Mothers

> **NIH NIH R03** · UNIVERSITY OF SOUTH CAROLINA AT COLUMBIA · 2020 · $74,500

## Abstract

PROJECT SUMMARY/ABSTRACT
 About 1 in 151 women in the US are carriers of a genetic abnormality called the FMR1 premutation.
Mothers who carry the FMR1 premutation are at risk for passing the mutated gene to their children, which may
result in fragile X syndrome. The FMR1 premutation is also associated with its own clinical symptoms, which
appear to worsen with age. New, emerging evidence suggests that premutation carrier mothers may
experience premature age-related decline in language production skills that may begin as early as the third or
fourth decade of life. Language production deficits impede effective communication, reduce perceptions of
competence, and negatively impact social interaction. Premutation carrier mothers are particularly vulnerable to
the negative consequences of language deficits, as they are the primary caregivers for their children with fragile
X and effective communication skills are necessary to care and advocate for their disabled children. Yet, a major
obstacle in the field is that all existing evidence has been gleaned from cross-sectional data. Longitudinal
research is needed to confirm the presence of age-related linguistic decline across early-to-middle adulthood.
There is also a need to better understand how environmental factors, such as elevated parenting stress
associated with caring for a child with a disability, contribute to the expression of premutation symptoms over
time. Poor understanding of the aging premutation phenotype and its mechanisms represents a substantial
barrier to effective clinical management of premutation carriers, as we lack the data needed to understand the
long-term effects of this genetic abnormality over time.
 The present study will represent one of the first longitudinal investigations of premutation carriers. We will
delineate age-related changes in language skills across early-to-mid adulthood (Aim 1) and determine the
effect of elevated parenting stress on aging trajectories (Aim 2). We are uniquely poised to pursue this work
given our access to a rare corpus of previously-collected longitudinal language samples from premutation
carrier mothers. We will use well-established language sample analytic techniques to extract new language
variables from these existing samples: propositional density, grammatical complexity, and dysfluency. Adopting
an innovative statistical approach—an accelerated longitudinal design-- we will track age-related change in
these features across early-to-mid adulthood (30-62 years). This work will contribute significantly to current
understanding of the aging premutation phenotype, inform critical age periods for intervention, and shed light on
parenting stress as a potential intervention target for ameliorating premutation symptoms.

## Key facts

- **NIH application ID:** 9892021
- **Project number:** 5R03HD098291-02
- **Recipient organization:** UNIVERSITY OF SOUTH CAROLINA AT COLUMBIA
- **Principal Investigator:** Jessica Klusek
- **Activity code:** R03 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $74,500
- **Award type:** 5
- **Project period:** 2019-04-01 → 2022-03-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9892021

## Citation

> US National Institutes of Health, RePORTER application 9892021, Aging Language Trajectories in Premutation Carrier Mothers (5R03HD098291-02). Retrieved via AI Analytics 2026-05-25 from https://api.ai-analytics.org/grant/nih/9892021. Licensed CC0.

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