SNP Shot: Genomic Insights

Arterial tortuosity syndrome (ATS) is a connective tissue disorder. Connective tissue provides strength and flexibility to various body structures, including blood vessels, skin, joints, and the digestive system.

As the name implies, ATS is marked by irregularities in blood vessels, specifically abnormal twists and turns (tortuosity) in the arteries, which carry blood from the heart throughout the body. This tortuosity arises from an unusual lengthening of the arteries; because the ends of the arteries are fixed, the extra length causes them to twist and curve. Other blood vessel abnormalities seen in ATS can include narrowing (stenosis), abnormal bulging (aneurysm), and small clusters of enlarged blood vessels visible under the skin (telangiectasia).

The complications from these abnormal arteries can be life-threatening. An aneurysm rupture or a sudden tear (dissection) in the artery wall can lead to severe blood loss. Blockage of blood flow to critical organs like the heart, lungs, or brain can cause heart attacks, breathing problems, and strokes. Stenosis forces the heart to overwork to pump blood, potentially leading to heart failure. Consequently, ATS is often fatal during childhood, although some individuals with milder cases can live into adulthood.

Beyond the circulatory system, ATS features stem from abnormal connective tissue elsewhere in the body. These can include extremely flexible joints (hypermobility) or joints with limited movement due to deformities (contractures), as well as unusually soft and stretchable skin. Some individuals may have long, thin fingers and toes (arachnodactyly), a curved spine (scoliosis), or a sunken (pectus excavatum) or protruding (pectus carinatum) chest. Organ protrusion through muscle gaps (hernias), intestinal elongation, or pouches in the intestinal walls (diverticula) can also occur.

Individuals with ATS often appear older than their actual age and have distinct facial characteristics. These include a long, narrow face with sagging cheeks, narrowed eye openings (blepharophimosis) with downward-sloping outer corners (downslanting palpebral fissures), a beaked nose with soft cartilage, a high-arched palate, a small lower jaw (micrognathia), and large ears. The cornea, the clear front part of the eye, may become cone-shaped and abnormally thin (keratoconus).

Inheritance:

ATS is inherited in an autosomal recessive manner. This means that both copies of the gene in each cell must carry a mutation for the condition to develop. Individuals with autosomal recessive conditions inherit one mutated copy of the gene from each parent, who are usually carriers and do not show signs or symptoms of the condition.