The WDR4gene provides instructions for making a protein that works together with another protein, METTL1, to help the cell make proteins correctly. This team adds a tiny chemical “mark” (called m⁷G46) onto certain tRNAs—small molecules that carry building blocks for making proteins.
What kinds of gene changes occur?
In children with WDR4-related conditions, several types of gene changes (variants) have been found:
• Missense changes:where one “letter” in the gene is changed, leading to a protein that has one incorrect building block. These changes can weaken the WDR4 protein or stop it from attaching properly to METTL1.
• Frameshift changes: small duplications in the gene that cause the protein to be cut short, making it nonfunctional.
• Splice-site changes: changes that affect how the gene’s instructions are put together, often leading to little or no workable WDR4 protein.
What do these mutations do?
All these changes interfere with the WDR4 protein’s ability to help place the m⁷G46 chemical mark on tRNAs. Without this mark:
• tRNAs do not fold or function properly
• protein production becomes less accurate and less efficient
• tissues that rely on rapid growth—especially the brain and kidneys—are most affected
How does this lead to disease?
Because the brain and kidneys need high levels of accurate protein production during development, the lack of proper tRNA modification can lead to:
• slowed brain growth (microcephaly)
• developmental delays
• seizures
• kidney problems (in some conditions)
• poor growth before and after birth
WDR4