SNP Shot: Genomic Insights

Isolated ectopia lentis is a condition affecting the eyes where the lens, the clear focusing structure at the front of the eye, is displaced from its normal central position. This displacement can occur in one or both eyes and is typically noticed during childhood. The lens may shift further out of position as time passes.

Visual impairment is common in isolated ectopia lentis. Individuals may experience nearsightedness (myopia) and astigmatism, a blurred vision caused by an irregularly shaped lens or cornea. They are also at risk for developing cataracts (clouding of the lens) and glaucoma (increased eye pressure) earlier in life than the general population. In rare cases, retinal detachment, a tear in the back lining of the eye, can occur, potentially leading to severe vision problems and even blindness.

The severity and nature of eye problems can differ significantly between individuals with isolated ectopia lentis, and even between the two eyes of the same person. The symptoms can also vary among affected family members.

Ectopia lentis is termed "isolated" when it occurs as the only health issue, without any related signs or symptoms affecting other parts of the body. In contrast, "syndromic" ectopia lentis occurs as part of a broader syndrome that involves multiple body systems. It is a characteristic of genetic syndromes like Marfan syndrome and Weill-Marchesani syndrome.

Inheritance:

Isolated ectopia lentis due to FBN1 gene mutations follows an autosomal dominant inheritance pattern. This means that only one copy of the mutated gene is enough to cause the condition. A person may inherit the mutation from an affected parent, or the mutation may arise spontaneously in a person with no family history of the disorder. Isolated ectopia lentis caused by ADAMTSL4 gene mutations follows an autosomal recessive inheritance pattern. This means that both copies of the gene must be mutated for the individual to develop the condition. Individuals with autosomal recessive conditions inherit one copy of the mutated gene from each parent, who are typically carriers and do not exhibit symptoms.