Which gene is commonly implicated in lissencephaly?

Which gene is commonly implicated in lissencephaly?

• A. FLNA
• B. LIS1
• C. SHH
• D. CTIP2

Answer: (B)

Lissencephaly arises when neurons fail to migrate properly to form the layered cerebral cortex during development. The LIS1 gene encodes a protein that works with the dynein motor complex to move migrating neurons along radial fibers. When LIS1 is mutated, this migration process is disrupted, leading to a smooth brain surface with abnormal or absent gyri and sulci—the hallmark of lissencephaly. This gene is one of the classic causes of the condition, explaining why it’s the best choice. The other genes have different roles in brain development. FLNA is mainly associated with periventricular nodular heterotopia, not lissencephaly. SHH is a signaling molecule important for early brain patterning, and CTIP2 is a transcription factor involved in cortical neuron differentiation, not a primary driver of lissencephaly.

Lissencephaly arises when neurons fail to migrate properly to form the layered cerebral cortex during development. The LIS1 gene encodes a protein that works with the dynein motor complex to move migrating neurons along radial fibers. When LIS1 is mutated, this migration process is disrupted, leading to a smooth brain surface with abnormal or absent gyri and sulci—the hallmark of lissencephaly. This gene is one of the classic causes of the condition, explaining why it’s the best choice.

The other genes have different roles in brain development. FLNA is mainly associated with periventricular nodular heterotopia, not lissencephaly. SHH is a signaling molecule important for early brain patterning, and CTIP2 is a transcription factor involved in cortical neuron differentiation, not a primary driver of lissencephaly.