HSD10 disease, infantile type is a rare neurometabolic disorder that typically shows normal development until about 6 to 18 months of age. After this period, children begin to experience a decline in development along with worsening neurological functions. This includes loss of previously acquired skills and issues with movement, vision, and hearing. In addition to neurodegeneration, affected children may develop seizures, epilepsy, severe heart problems (cardiomyopathy), lethargy, weak muscle tone (hypotonia), poor feeding, and abnormal movements such as choreoathetosis. Laboratory findings often reveal high levels of isoleucine metabolites in the blood and urine. The condition is usually life-limiting, with many children not surviving beyond 2 to 4 years of age.

People with this condition may experience developmental regression, progressive loss of motor skills, visual and hearing problems, seizures, and epilepsy. They can also develop serious heart problems, experience lethargy, hypotonia, poor feeding, and abnormal movements such as choreoathetosis.

The underlying cause of HSD10 disease, infantile type relates to a neurometabolic disorder, indicated by the abnormal metabolism of isoleucine. However, specific genetic factors or detailed causes are not provided in the available information.