# Discovery and characterization of a novel candidate gene for inherited hearing loss

> **NIH NIH F30** · UNIVERSITY OF WASHINGTON · 2021 · $39,876

## Abstract

PROJECT SUMMARY/ABSTRACT
The goal of this proposal is to characterize a novel candidate gene for inherited hearing loss using clinical, genomic,
and biological tools. The approach combines clinical evaluation of informative families, genome sequencing to identify
candidate genes, in vitro analysis of the consequences of candidate mutant alleles on gene and protein function, and in
vivo recreation and full evaluation of the phenotype observed in CRISPR-Cas9 mice bearing the human candidate
genotype. The identification of new genes for hearing loss will expand diagnostic genetic testing, yield insight into cellular
and molecular mechanisms of hearing, and allow for future development of therapies targeting these mechanisms.
My proposal describes the application of this approach to a consanguineous family with two children with congenital,
bilateral, profound, non-syndromic hearing loss. The children are homozygous for the missense mutation ALDOC
p.R149C. ALDOC encodes aldolase C, one of three aldolase isozymes (A, B, and C) that are critical for glycolysis and
fructose metabolism. ALDOC is highly expressed in brain and in the sensory epithelium of the inner ear and plays a role
in neurodevelopment. Mutations in its paralog, ALDOB, lead to hereditary fructose intolerance where accumulation of
the substrate fructose-1-phosphate causes hepatocyte injury and cell death. Here, we propose a similar mechanism
within the inner ear for ALDOC-related hearing loss and outline experimental approaches to test this hypothesis.
Aim 1. To evaluate the biochemical properties of mutant ALDOC p.R149C, I first purified wild-type and mutated aldolase
C from E. coli and demonstrated near complete loss of catalytic activity of the mutant protein. To further quantify this
mutation’s effects, I will complete thermostability testing, Michael-Menten enzyme kinetics calculations, and also
evaluate its effect on aldolase heteromers by creating and assaying an aldolase A/C hybrid set.
Aim 2. To evaluate the phenotypic effects of Aldoc p.R149C, I designed a CRISPR-Cas9 mouse carrying the human
mutation. Preliminary results from homozygous mice show a mild hearing loss. Next, I will thoroughly evaluate the
hearing of the homozygotes, with and without fructose supplementation, by auditory brainstem response (ABR) testing
and analyze cochlear explants by immunohistochemistry and scanning electron microscopy.
Aim 3. To determine the cell type(s) involved in ALDOC p.R149C hearing loss, I will utilize single-cell RNA sequencing
to identify differences in inner ear cell populations between wild type and Aldoc p.R149C homozygous mice.
My project will provide training across auditory neuroscience, biochemistry, and genomics. It will afford ample
opportunities for growth in scientific literacy and communication, experimental design and execution, and
interdisciplinary collaboration. It is complemented by clinical exposure to otolaryngology and embedded in the UW
MSTP, which has 50 years’ ...

## Key facts

- **NIH application ID:** 10228506
- **Project number:** 1F30DC018702-01A1
- **Recipient organization:** UNIVERSITY OF WASHINGTON
- **Principal Investigator:** Ryan James Carlson
- **Activity code:** F30 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2021
- **Award amount:** $39,876
- **Award type:** 1
- **Project period:** 2021-06-16 → 2022-03-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10228506

## Citation

> US National Institutes of Health, RePORTER application 10228506, Discovery and characterization of a novel candidate gene for inherited hearing loss (1F30DC018702-01A1). Retrieved via AI Analytics 2026-05-28 from https://api.ai-analytics.org/grant/nih/10228506. Licensed CC0.

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