SNP Shot: Genomic Insights

Schindler disease is a genetic condition that mainly affects the nervous system.

This disease presents in three forms. Type I, also known as the infantile form, is the most serious. Infants with type I seem normal at birth, but between 8 and 15 months old, they cease acquiring new skills and begin to regress, losing previously learned abilities (developmental regression). As the disease progresses, individuals experience blindness and seizures, eventually becoming unaware and unresponsive. Life expectancy for those with type I is usually limited to early childhood.

Schindler disease type II, also called Kanzaki disease, is a less severe form that typically manifests in adulthood. Individuals may experience mild cognitive decline and sensorineural hearing loss due to inner ear abnormalities. Weakness and sensory loss can occur due to peripheral nervous system problems. Angiokeratomas, small, dark red spots caused by clusters of enlarged blood vessels on the skin, are a hallmark of this type.

Schindler disease type III exhibits severity between types I and II. Some individuals show symptoms from infancy, including developmental delays, seizures, cardiomyopathy (weakened, enlarged heart), and hepatomegaly (enlarged liver). Others display neurodevelopmental issues starting in early childhood, with features similar to autism spectrum disorder, which affects communication and socialization skills.

Inheritance:

The inheritance pattern for this condition is autosomal recessive. This means that a mutation must be present in both copies of the responsible gene within each cell for the disorder to manifest. Both parents of an affected individual carry one copy of the mutated gene, but generally do not display any signs or symptoms of the condition themselves.