A Newborn Test for MLD Could Help Prevent Lethal Consequences

By: Natalie Homan from In The Cloud Copy

Connie Elson was a happy, independent little girl before she started showing worrying symptoms at the age of four. After many doctor visits, her family learned that she had metachromatic leukodystrophy (MLD), a degenerative brain condition that will ultimately take her life. Connie’s family and friends have had to watch helplessly as Connie has lost her ability to walk, talk, and even sit on her own.

To Connie’s parents, perhaps their greatest tragedy is that Connie’s symptoms might have been prevented if they had known about her disease before it took hold. MLD has characteristically been a death sentence, but new research has opened up a door to help treat children with the disorder. This treatment can only work if it is done before symptoms appear.

Who Can Get MLD?

MLD is an inherited disorder caused by the failure of a specific gene to function as it should. For a child to inherit MLD, both of their parents must be genetic carriers of MLD (meaning that of the two copies of the gene in their DNA, one is healthy while the other is defective). Furthermore, each parent must pass the defective copy of the gene to their child. Siblings may have two copies of the healthy gene or else one each of the healthy and defective gene. In either of the latter cases, the siblings will not have the disease at all, although they do have the chance of passing it onto their children. Connie’s little brother, Joe, also carries both copies of the defective gene.

What are the Symptoms of MLD?

A person with MLD can’t produce arylsulfatase-A (ARSA), the enzyme that helps cells break down sulfatides, which are present in the myelin coating surrounding nerve cells. Without ARSA, the sulfatides build up so much that they gradually cause the myelin coating to break down. Without the myelin sheath, nerve cells will be permanently damaged. The liver and kidneys may also be damaged.

In a person with MLD, progressive nerve damage will cause gradual worsening of symptoms and eventually death. In children especially, it can be one of the most heartbreaking diseases to witness. Like Connie, a child who could once run and talk will gradually lose the ability to move freely, learn new things, and speak. This regression most commonly begins between 6 months and two years, although, as in Connie’s case, symptoms can begin later as well.

Is There a Cure?

Although Connie’s disease is heartbreaking to watch, the fact that she was diagnosed probably saved the life of her little brother, Joe, who tested positive for MLD in 2014 when he was three-and-a-half. Since Joe was not showing symptoms, he was eligible for gene therapy treatment. This treatment involves a transplant of stem cells from donated umbilical cord blood or bone marrow. These cells contain normal levels of the ARSA enzyme and can help stop the progression of the disease, although they cannot cure damage that has already been done. It was too late for Connie to try the treatment, but Joe did and today is well and thriving.

A Need for Better Screening

Connie’s parents are pushing for the UK, where they live, to expand the genetic testing done on newborns so that it includes MLD and other rare genetic diseases (in comparison, the United States tests for 59 conditions, Iceland tests for 47, and the UK tests for only nine). It’s impossible to be certain, but if they had known about Connie’s illness before symptoms started, she might have been eligible for gene therapy treatment and still be an active, vibrant little girl. Her parents are making every effort to ensure that other children have the chance to fight this life-threatening condition.

If you live in the UK, you can sign this petition to expand the newborn screening program.

Learn more about this story here.

 


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