# Brain Abnormalities and Neurobehavioral Deficits in Hypoplastic Left Heart Syndrome

> **NIH NIH F30** · UNIVERSITY OF PITTSBURGH AT PITTSBURGH · 2021 · $51,036

## Abstract

PROJECT SUMMARY
Hypoplastic left heart syndrome (HLHS), a severe congenital heart disease (CHD), is associated with high risk
for neurodevelopmental disabilities. In fact, over 30% of HLHS survivors experience moderate to severe
neurocognitive impairment. While brain abnormalities in HLHS patients are typically thought to be secondary to
substrate delivery deficits from circulatory disturbance, our recent recovery of HLHS mutant mice with brain
abnormalities point to a shared genetic etiology for the heart defects and the neurodevelopmental disabilities.
This is supported by other studies showing CHD patients with de novo mutations in chromatin modifying genes
are at increased risk for neurodevelopmental disorders that can include cognitive, motor, social and language
impairments. We observed HLHS mutant mice to have brain abnormalities involving the cortex, hippocampus,
and olfactory bulb, forebrain structures also frequently affected in HLHS patients. We showed HLHS and brain
abnormalities in the Ohia mouse line have a digenic etiology, arising from mutations in two genes: Sin3a-
associated protein 130 (Sap130), a chromatin modifying protein mediating transcriptional repression, and
protocadherin a9 (Pcdha9), a protein involved in cell-cell adhesion. As chromatin modifying genes are already
implicated in autism and also in neurodevelopmental impairment in CHD patients, insights into the role of Sap130
in the brain defects of the Ohia HLHS mice will have broad relevance for understanding the causes for poor
neurodevelopmental outcomes in CHD and non-CHD patients. In this study, we will investigate the hypothesis
that Sap130 deficiency perturbs brain development, causing brain dysmaturation with altered neural network
connectivity and neurobehavioral deficits. In Aim 1, we will investigate the cellular and molecular mechanisms
driving the brain dysmaturation, focusing on the forebrain. This will entail examining neurogenesis and cortical
plate formation and conducting molecular profiling with RNAseq and ChIPseq analyses. In Aim 2, we will conduct
multi-modal structural magnetic resonance imaging (MRI) that will include diffusion tensor imaging (DTI) to
characterize the forebrain dysplasia and neural network connectivity changes contributing to the brain
dysmaturation defects. To determine if behavioral defects may be elicited by the brain dysmaturation and neural
network connectivity perturbations, in Aim 3 we will conduct a battery of rodent neurobehavioral assessments.
The studies in Aims 2 and 3 will be carried out using a floxed Sap130 allele with forebrain targeted Cre mediated
Sap130 deletion. This will allow mutant mice to survive to adulthood without heart defects. Such mice will be
generated with or without the Pcdha9 mutation, allowing determination of the role of Pcdha9 in the brain
abnormalities. Together these studies will yield new insights into the developmental etiology of the HLHS
associated brain abnormalities and whether specif...

## Key facts

- **NIH application ID:** 10189677
- **Project number:** 5F30HD097967-03
- **Recipient organization:** UNIVERSITY OF PITTSBURGH AT PITTSBURGH
- **Principal Investigator:** George Christopher Gabriel
- **Activity code:** F30 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2021
- **Award amount:** $51,036
- **Award type:** 5
- **Project period:** 2019-05-17 → 2024-05-16

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10189677

## Citation

> US National Institutes of Health, RePORTER application 10189677, Brain Abnormalities and Neurobehavioral Deficits in Hypoplastic Left Heart Syndrome (5F30HD097967-03). Retrieved via AI Analytics 2026-06-11 from https://api.ai-analytics.org/grant/nih/10189677. Licensed CC0.

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