thioredoxin like 4A
The TXNL4A gene provides instructions for making one part (subunit) of a protein complex called the major spliceosome, which is the larger of two types of spliceosomes found in human cells. Spliceosomes help process messenger RNA (mRNA), which is a chemical cousin of DNA that serves as a genetic blueprint for making proteins. The spliceosomes recognize and then remove regions called introns to help produce mature mRNA molecules from immature mRNA molecules.
At least 10 TXNL4A gene mutations have been identified in people with Burn-McKeown syndrome, a disorder that is present from birth (congenital) and involves abnormalities of the nasal passages, characteristic facial features, hearing loss, heart abnormalities, and short stature. Most people with Burn-McKeown syndrome have a different genetic change in each of the two copies of the TXNL4A gene in each cell; this situation is called compound heterozygosity. In one copy of the gene, a TXNL4A gene mutation results in a protein with impaired function, or no protein at all is produced. The other copy of the TXNL4A gene has a deletion of a small amount of genetic material in an area near the TXNL4A gene called the promoter region, which controls the production of protein from that gene. This genetic change reduces protein production.
Research suggests that reduced quantities of the protein produced from the TXNL4A gene affect the assembly of the major spliceosome and change the production of a particular group of mRNA molecules. The details of these changes and their relationship to the specific signs and symptoms of Burn-McKeown syndrome are unknown. However, mutations in several genes involved in the spliceosome have been shown to cause other conditions with abnormalities affecting the head and face (craniofacial malformations), so craniofacial development is thought to be particularly sensitive to spliceosome problems.
- DIM1 protein homolog
- spliceosomal U5 snRNP-specific 15 kDa protein
- thioredoxin-like 4A
- thioredoxin-like U5 snRNP protein U5-15kD