BCS1L

BCS1L is a gene that encodes a protein involved in the assembly of the respiratory chain complex III in the mitochondria. Mutations in this gene have been associated with a variety of diseases, including Björnstad syndrome, Gracile syndrome, and Mitochondrial complex III deficiency, nuclear type 1.

Function

The BCS1L gene provides instructions for making a protein that is found in mitochondria, the energy-producing centers within cells. This protein is involved in the final stages of assembly of an enzyme complex called cytochrome c reductase, also known as respiratory chain complex III. This complex is essential for normal mitochondrial function.

Clinical significance

Mutations in the BCS1L gene can lead to a variety of diseases. These include:

• Björnstad syndrome: This condition is characterized by hearing loss and a distinctive hair abnormality called pili torti, which increases the risk of hair breakage.
• Gracile syndrome: This is a severe metabolic disorder that affects several body systems, particularly the nervous system. Affected individuals often have a buildup of a molecule called lactic acid in the body (lactic acidosis), which can cause nausea, vomiting, severe breathing problems, and an abnormal heartbeat.
• Mitochondrial complex III deficiency, nuclear type 1: This is a severe condition that affects many parts of the body, including the brain, heart, liver, and muscles. Symptoms can include muscle weakness, heart problems, and a variety of other symptoms.

See also

• Mitochondrial disease
• Respiratory chain