What chromosome is TCOF1?

The Treacher Collins Syndrome Collaborative Group (1996) found that the treacle gene (TCOF1), which is mutant in Treacher Collins syndrome, is located on chromosome 5q in a gene-rich region of the human genome.

Can you be a carrier of Treacher Collins syndrome?

If an individual receives one normal gene and one gene for the disease, the person will be a carrier for the disease, but usually will not show symptoms. The risk for two carrier parents to both pass the defective gene and, therefore, have an affected child is 25% with each pregnancy.

What chromosome is Treacher Collins syndrome?

Treacher Collins Syndrome is believed to be caused by a change in the gene on chromosome 5, which affects facial development. About 40% of the time, one parent has Treacher Collins Syndrome.

How does the TCS affect the person’s appearance?

People with TCS often have eyes that slant downward, sparse eyelashes, and a notch in the lower eyelids called an eyelid coloboma. Some individuals have additional eye abnormalities that can lead to vision loss. It also characterized by absent, small, or unusually formed ears.

What causes Treacher Collins syndrome?

Mutations in the TCOF1, POLR1C, or POLR1D gene can cause Treacher Collins syndrome. TCOF1 gene mutations are the most common cause of the disorder, accounting for 81 to 93 percent of all cases. POLR1C and POLR1D gene mutations cause an additional 2 percent of cases.

What is the history of Treacher Collins syndrome?

Thomson was the first to refer to this syndrome in 1846. In 1900, Dr E Treacher Collins, a British ophthalmologist, described two children who had very small cheek bones and notches in their lower eyelids. Therefore, the condition gets its name from him.

What are the signs and symptoms of TCOF1 mutations?

Teber et al. (2004) identified TCOF1 mutations in 28 of 36 (78%) patients with a clinically unequivocal diagnosis of TCS. The most frequent findings were downward-slanting palpebral fissures, hypoplasia of the zygomatic complex, hypoplasia of the mandible, conductive deafness, any degree of microtia, and atresia of the external ear canal.

How many exons are in the TCOF1 gene?

So et al. (2004) examined mouse Tcof1 transcripts and identified a variant containing an additional exon (16A). Gladwin et al. (1996) defined the intron-exon structure of the TCOF1 gene, identified 7 exons, and derived intronic sequences.

How many domains does TCOF1 have?

Dixon et al. (1997) isolated the coding sequence of the gene, designated TCOF1, and determined that it encodes a low complexity, serine/alanine-rich protein of approximately 144 kD. The deduced 1,411-amino acid protein has 3 domains with unique N and C termini and a large central repeat domain.