Developmental brain malformations are at the core of significant neurological diseases affecting many families in the United States and around the world. Epilepsy, specific learning deficits and intellectual disabilities, cerebral palsy, and abnormalities of brain size can often be attributed to pathological malformations of the cerebral cortex. Although symptoms such as epilepsy and intellectual disabilities may appear broadly in the population for any number of reasons, our focus on those cases associated with cortical malformations highlights individual developmental pathways likely represented by innumerable and rare Mendelian alleles. Our lab has uncovered dozens of genes associated with these conditions, and we are beginning to dissect the mechanisms underlying early cortical development. However, we know many more genes are yet to be discovered and these currently unidentified genes will provide even more important insight into brain development and function. The goal of our research is to identify novel genetic factors that result in abnormal human cerebral cortical development. This is achieved through 1] ascertaining families with congenital brain malformations, presumably due to inherited factors, and categorizing conditions using neuroimaging data, 2] identifying the genes that harbor mutations that cause the malformations, and 3] describing the function of these genes. We focus on the Middle East for ascertainment of families, where the prevalence of intra-familial marriage and large family size enriches this population for rare Mendelian disorders and offers significant power to distinguish gene targets through homozygosity mapping. The causative mutations are then identified using whole exome sequencing. The mutated gene is further characterized in cell lines, zebrafish, and mouse models in order to elucidate its function. The discovery of new genes, which when mutated result in abnormal brain development, impacts human health in several ways. These discoveries 1] provide insight into classification and diagnosis of these often devastating conditions that can be quickly translated to clinical practice, 2] permit improved genetic counseling and testing for concerned families, and 3] offer an enhanced understanding of the underlying molecular processes of the developing human brain which can inform the conception of potential future therapies or interventions. These treatments may apply not only to our specific, often under-served, patient populations, but also more broadly to numerous patients impacted by the relatively common symptoms of seizures and intellectual and motor impairments. Hence, our research works to reduce the burden of neurologic disease on our human society and does so with important short and long-term implications.

Public Health Relevance

Human brain development is a complicated and poorly understood process and when something interferes with it, devastating medical problems can result. Our goal is to better understand the normal process of brain formation and growth, which we do by studying patients with severe neurological symptoms and abnormal brain structure. These individuals provide examples of when something has gone wrong with the normal process and by trying to understand exactly what happened, we can gain insight into the normal pathways of brain development while finding ways of identifying and treating patients affected by these significant neurological conditions.

Agency
National Institute of Health (NIH)
Institute
National Institute of Neurological Disorders and Stroke (NINDS)
Type
Research Project (R01)
Project #
5R01NS035129-20
Application #
9312883
Study Section
Developmental Brain Disorders Study Section (DBD)
Program Officer
Whittemore, Vicky R
Project Start
1997-07-01
Project End
2019-07-31
Budget Start
2017-08-01
Budget End
2018-07-31
Support Year
20
Fiscal Year
2017
Total Cost
Indirect Cost
Name
Boston Children's Hospital
Department
Type
DUNS #
076593722
City
Boston
State
MA
Country
United States
Zip Code
02115
Walsh, Christopher A (2018) Rainer W. Guillery and the genetic analysis of brain development. Eur J Neurosci :
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