SNP Shot: Genomic Insights

Vici syndrome is a serious, early-onset disorder affecting numerous bodily systems. Key features include abnormalities in the brain, immune system, heart, skin, and eyes. Less frequently, other organs and tissues are affected.

A hallmark of Vici syndrome is agenesis of the corpus callosum, a brain malformation where the structure connecting the brain's hemispheres doesn't fully develop before birth. Pontine hypoplasia (underdevelopment of the pons) and reduced myelin (the protective covering of nerve cells) are other potential brain abnormalities. Furthermore, the brain tissue can deteriorate over time, leading to microcephaly (an unusually small head).

These brain problems cause significant developmental delays in individuals with Vici syndrome. Affected infants often exhibit hypotonia (weak muscle tone). While some may roll over, they often lose this ability. They are unable to sit or walk, and they do not develop speech.

Another defining characteristic of Vici syndrome is immune deficiency, leading to frequent, potentially life-threatening infections. Respiratory infections are the most common, followed by gastrointestinal and urinary tract infections.

Cardiomyopathy, a potentially fatal heart condition, frequently affects children with Vici syndrome. This condition progressively impairs the heart's ability to pump blood effectively. Some children also have congenital heart defects (present at birth).

Other significant features include hypopigmentation (lighter skin and hair compared to family members with similar ethnic backgrounds) and eye problems, such as cataracts (clouding of the lens) or other abnormalities, which can impair vision.

Less common signs and symptoms include seizures, sensorineural hearing loss (due to inner ear abnormalities), cleft lip (with or without cleft palate), unusual facial features, and impaired function of the thyroid, liver, or kidneys. Many affected infants experience failure to thrive, with slower growth and weight gain than expected.

Because of the severity of Vici syndrome, most individuals do not survive past the age of 5.

Inheritance:

Vici syndrome follows an autosomal recessive inheritance pattern. This means that both copies of the responsible gene must have mutations for the condition to manifest. Individuals with Vici syndrome inherit one mutated copy from each parent, who are typically carriers but do not exhibit symptoms themselves.