Multiple sulfatase deficiency (MSD) is a condition that affects different parts of the body, including the brain, bones, and skin.
There are three main types of MSD; the neonatal type is the most severe type, and symptoms start soon after birth. Sadly, individuals with neonatal MSD usually don’t live past their first year. They experience various problems like fluid around the brain, enlarged organs, hearing loss, delays in development, movement issues, seizures, dry/scaly skin, and bone abnormalities. The late-infantile form of MSD is the most common type, and symptoms typically show up between birth and 2 years of age. Children with late-infantile MSD initially develop normally but then start losing speech and mental abilities progressively. They become weak, have difficulty walking, and experience muscle stiffness. Other symptoms include changes in bones and dry/scaly skin. Unfortunately, individuals with this form usually don’t survive past childhood. The third form, juvenile MSD, is the rarest type, and symptoms appear between 2 and 4 years of age. Affected individuals have a normal start in development but then face a loss of speech and motor skills. The juvenile form usually progresses more slowly than the late-infantile form. There is no cure for MSD, so treatment focuses on managing specific symptoms and providing support. For instance, orthopedists can help with bone changes like scoliosis, and dry, scaly skin can be treated with petroleum jelly or lotion.
MSD is caused by pathogenic (disease-causing) variants in the SUMF1 gene and exhibits autosomal recessive inheritance. This means that both parents must be carriers to have a 25% chance to have a child with the condition. The risk of being a carrier is based on a person’s ancestry or ethnic background. For example, individuals of Ashkenazi Jewish descent have a 1 in 298 chance to be a carrier.
Other names for this condition are Austin syndrome, juvenile sulfatidosis (Austin type), and mucosulfatidosis.