Genomics of human congenital hydrocephalus

Area of Science:

• Neuroscience
• Genetics
• Developmental Biology

Background:

• Congenital hydrocephalus (CH) involves enlarged brain ventricles due to cerebrospinal fluid (CSF) accumulation, typically managed with neurosurgical CSF diversion.
• Persistent ventriculomegaly and poor neurodevelopmental outcomes post-surgery indicate gaps in understanding CH pathogenesis.
• Current treatments focus on CSF shunting, but underlying disease mechanisms remain incompletely understood.

Purpose of the Study:

• To investigate the genetic underpinnings of congenital hydrocephalus (CH) beyond pathological CSF accumulation.
• To explore the role of genetic mutations in early brain development as a cause of CH.
• To assess the potential of whole-exome sequencing (WES) for re-classifying CH and improving patient management.

Main Methods:

• Analysis of whole-exome sequencing (WES) data from patients with sporadic congenital hydrocephalus (CH).
• Examination of genetic mutations, including de novo and inherited variants, contributing to CH.
• Investigation of the functional roles of identified CH genes in neural stem cell regulation and human transcriptional networks.

Main Results:

• Rare, damaging mutations (de novo and inherited) with significant effect explain approximately 25% of sporadic CH cases.
• Many identified CH genes are critical regulators of neural stem cell growth and differentiation.
• These genes converge in transcriptional networks and cell types involved in fetal neurogliogenesis.

Conclusions:

• Genetic disruption of early brain development is a primary pathomechanism in a substantial portion of sporadic CH.
• This finding offers new insights into both human brain development and hydrocephalus pathogenesis.
• WES can serve as a clinical tool for molecular re-classification of CH, enhancing genetic counseling, prognostication, and treatment stratification.