SNP Shot: Genomic Insights

RNAse T2-deficient leukoencephalopathy is a brain disorder causing neurological issues that typically appear in infancy. While these problems usually don't worsen over time, affected individuals often experience significant intellectual disability, muscle stiffness (spasticity), and delayed motor skill development (sitting, crawling, walking). Many are unable to walk or speak. Other possible neurological features include sensorineural hearing loss (inner ear abnormality), seizures, involuntary writhing hand movements (athetosis), uncontrolled muscle tensing (dystonia), and involuntary eye movements (nystagmus). Some individuals may also have distinctive facial features, sometimes described as a "doll-like face."

The neurological problems stem from brain abnormalities, specifically leukoencephalopathy, detectable through medical imaging. Leukoencephalopathy involves the brain's white matter, composed of myelin-covered nerve fibers. Myelin acts as insulation, facilitating rapid nerve impulse transmission. In RNAse T2-deficient leukoencephalopathy, insufficient myelin production during development leads to patchy white matter lesions in the brain. Furthermore, individuals may have cysts in the temporal lobes and enlarged brain ventricles (fluid-filled cavities). White matter lesions are mainly located around the cysts and ventricles. Microcephaly (abnormally small head and brain size) is also a common feature.

Inheritance:

RNAse T2-deficient leukoencephalopathy follows an autosomal recessive inheritance pattern. This means that an individual must inherit a variant in both copies of the responsible gene to develop the condition. Both parents of an affected child carry one copy of the altered gene, but usually do not exhibit any signs or symptoms of the disorder.