Swift diagnosis and new trials could help people with lysosomal storage disorders.
Clinical trials could help tackle some types of lysosomal storage disorders (LSDs)
LSDs are inherited genetic disorders in which the body’s cells lack specific enzymes needed to break down substances that would normally be recycled. The result is a build-up of substances that cause a range of medical problems depending on the enzyme that is lacking, the degree of deficiency and how that affects the body.
For instance, lysosomal acid lipase (LAL) deficiency results in accumulation of cholesterol esters and triglycerides in the cells, leading to an accumulation of fats in the liver, gut and blood vessels. “Babies born with early-onset LAL deficiency, often called Wolman disease, rarely live beyond a year,” says Dr Derralynn Hughes, a lysosomal storage disorders specialist and researcher at the Royal Free London NHS Foundation Trust.
Rarely seen diseases lead to multiple diagnoses
Late onset LAL deficiency (cholesteryl ester storage disease), affects 25 individuals per million and appears in older children and adults. It may lead to liver fibrosis, cirrhosis, liver failure and death. “This is rarely seen by doctors, so many patients are only identified after having multiple diagnoses,” says Dr Hughes. Swift diagnosis is important because treatment delay means greater damage.
Survival rates are increasing
There are no cures at present and treatment under development involves enzyme replacement therapy, but Dr Hughes says: “Recent drugs trails in babies with Woman disease seem to indicate that survival past 12 months is a possibility.”
Clinical trials on older LAL disease patients are under way now, and there are screening initiatives among people with suggestive lipid profiles.
MPS III-B, or Sanfillipo syndrome, another LSD, results from a deficiency of the enzyme required to break down heparan sulfate. It appears in young children who show developmental delay, sleep disturbances, cognitive and behavioural problems, and characteristic facial features.
“Treatment is in trial with ERT but often much damage is done before the child is diagnosed,” says Dr Hughes. “That’s why we must raise awareness among patients and physicians, many of whom never see LSDs. If you suspect your child might have one of these disorders, consult a doctor, if necessary taking this article with you.”
